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"Efecto macho" y su relación con el anestro postparto en la oveja pelibuey amamantando

FRANCISCO CRUZ ESPINOZA (2011)

Tesis (Maestría en Ciencias, especialista en Ganadería).- Colegio de Postgraduados, 2011.

Se realizaron dos experimentos para evaluar el “efecto macho” y el amamantamiento en el restablecimiento de la actividad ovárica postparto en ovejas Pelibuey. En el experimento 1, se utilizaron 73 ovejas, que se distribuyeron al azar en cuatro tratamientos: T1, amamantamiento continuo sin macho (n=18), crías con madres durante todo el experimento; T2, amamantamiento continuo con macho (n=18), igual que T1 más “efecto macho” (07:00 a 07:30 h y de 16:00 a 16:30 h); T3, amamantamiento controlado con macho (n=18), las crías tuvieron contacto con sus madres en dos periodos (08:00 a 08:30 h y de 18:00 a18:30 h); y, T4, amamantamiento controlado sin macho (n=19). En el experimento 2, se utilizaron 108 ovejas, distribuidas al azar en dos tratamientos: T1, amamantamiento continuo con macho (n=53), crías junto con sus madres durante toda la fase experimental más “efecto macho” (07:00 a 07:30 h y de 16:00 a 16:30 h); y T2, amamantamiento controlado con macho (n=55), igual que T1, solo que las crías tenían contacto con sus madre en dos periodos (08:00 a 08:30 h y de 18:00 a 18:30 h). El estudio se realizó durante noviembre-febrero de 2009-2010 (experimento 1) y en noviembre-enero 2010-2011 (experimento 2). En el experimento 1, se observó que las ovejas de T3 ovularon a los 27.72 ± 0.56 d postparto (p<0.05) diferente de las ovejas de T1, T2 y T4. Las ovejas de T3 ovularon el 100% siendo diferente de las de T4 (p<0.05). En el experimento 2, se observó que las ovejas con T2, presentaron el primer estro a los 34.02 ± 1.28 (p<0.05) diferente de las de T1, pero no al segundo estro (p>0.05) (52.19 ± 1.58 y 48.36 ± 1.17 d; T1 y T2 respectivamente). No se observaron diferencias (p>0.05) en el porcentaje de ovulación con T1 y T2, al primer y segundo celo; tampoco en el porcentaje de gestación total (58.49 y 67.27 %), porcentaje de parición total (54.72 y 63.64 %), prolificidad total (1.79 y 1.74) y fecundidad (0.98 y 1.11). Por lo anterior, se concluye que en las ovejas Pelibuey amamantando, el “efecto macho” induce el restablecimiento ovárico más temprano. _______________ “MALE EFFECT” AND ITS RELATION WITH THE POSTPARTUM ANESTRUS IN PELIBUEY NURSING EWE. ABSTRACT: To evaluate the “male effect” and the suckling on the reestablishment of the ovarian activity postpartum in Pelibuey ewes, two experiments were conducted. In experiment 1, 73 ewes were distributed at random into four treatments: T1, continuous suckling without male (n=18), the lambs remained with their mothers throughout the experiment; T2, continuous suckling with male (n=18) just as T1 plus the “male effect” (07:00 to 07:30 h and 16:00 to 16:30 h); T3, controlled suckling with male (n=18), the lambs had contact with their mothers in two periods (08:00 to 08:30 h and 18:00 to 18:30 h) and, T4, controlled suckling without male (n=19). In experiment 2, 108 ewes were distributed at random in two treatments: T1, continuous suckling with male (n=53), lambs along with their mothers during all the experimental phase plus the “male effect” (07: 00 to 07:30 h and 16:00 to 16:30 h); and T2, controlled suckling with male (n=55), just as in T1, only that the lambs had contact with their mothers in two periods (08: 00 to 08:30 h and 18:00 to 18:30 h). The study was carried out from November 2009 to February 2010 (experiment 1) and from November 2010 to January 2011 (experiment 2). In experiment 1, it was observed that the ewes of T3 ovulated 27,72 ± 0,56 d postpartum different (p<0.05) from the ewes of T1, T2 and T4. All of the ewes of T3 ovulated compared to those of T4 (p<0.05). In experiment 2, it was observed that the ewes of T2 displayed first oestrus 34,02 ± 1.28 different (p<0.05) from the T1 ewes, but not in the second oestrus (p>0.05) (52.19 ± 1.58 and 48.36 ± 1.17 d; T1 and T2 respectively). Differences were not observed (p> 0.05) in the percentage of ovulation with T1 and T2, to first and the second estrus; neither in the percentage of total gestation (58,49 and 67,27%), percentage of total deliveries (54,72 and 63,64%), total prolificacy (1,79 and 1.74) and fecundity (0,98 and 1.11). In conclusion, in Pelibuey nursing ewes the “male effect” induces an early ovarian reestablishment activity.

Master thesis

Ovinos Bioestimulación Periodo postparto Ovulación Amamantamiento Sheep Bioestimulation Postpartum period Ovulation Suckling CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

"Efecto macho" en la ovulación postparto de ovejas pelibuey amamantando

MA. ISABEL MONTIEL CASTELÁN (2014)

Tesis (Maestría en Ciencias, especialista en Ganadería).- Colegio de Postgraduados, 2014.

Se realizaron dos experimentos para evaluar el efecto del amamantamiento y “efecto macho” en la ovulación en el periodo postparto (PP) en la oveja Pelibuey. En el experimento 1, a los 10 días postparto, dos tratamientos se asignaron al azar a las ovejas con sus crías: Amamantamiento continuo (AC) y amamantamiento controlado (Ac). En AC, las crías permanecieron todo el tiempo con ellas (24h d-1) y en Ac, crías permanecieron por dos periodo de 30 min d-1 (08:00 a 08:30 h y de 17:00 a 17:30 h). En el experimento 2, se hizo el mismo sistema de manejo de amamantamiento que en experimento 1, al azar se conformaron cuatro grupos; amamantamiento continuo (AC), amamantamiento continuo con “efecto macho” (AC+EM), amamantamiento controlado (Ac) y amamantamiento controlado con “efecto macho” (Ac+EM). En el día 24 PP se sincronizaron con CIDR por 9 días, al retiro del dispositivo se empezó el “efecto macho” (cada 6 h por 3 d). A partir del día 7 al 45 postparto, se tomaron muestras de sangre para determinar progesterona en plasma en ambos experimentos, así como el registro cada semana de peso corporal de ovejas y corderos desde el parto hasta el destete (60 d). En el experimento 1 se observó, que las ovejas con Ac ovularon 52.50 %, siendo diferente (p˂0.05) de las de AC. En el experimento 2, el porcentaje de ovejas que ovularon fue menor en AC (47.37 %; p˂0.05) comparado con AC+EM, Ac y Ac+EM (95, 85 y 95 %, respectivamente). Los cambios de peso corporal de ovejas y corderos no fueron diferentes (p>0.05) entre tratamientos; sin embargo, fue evidente la pérdida de peso en corderos con Ac+EM. Por lo anterior, se concluye que el amamantamiento controlado restablece la actividad ovárica en la oveja Pelibuey y el “efecto macho” induce y sincroniza la ovulación sin afectar el peso corporal de ovejas y corderos. _______________ “MALE EFFECT” ON POST-PARTUM OVULATION IN SUCKLING PELIBUEY EWES. ABSTRACT: Two experiments were carried out to evaluate the effect of suckling and “male effect” on ovulation in the post-partum period (PP) of Pelibuey ewes. In experiment 1, 10 days post-partum, two treatments were randomly assigned to ewes and their offspring: continuous suckling (AC) and controlled suckling (Ac). In AC, the lambs remained continuously with the ewes (24h d-1), while in Ac, the lambs were placed with the ewes for two 30 min d-1 periods (08:00 to 08:30 h and 17:00 to 17:30 h). In experiment 2, the same suckling treatments as in experiment 1 were used. Four groups were randomly formed: continuous suckling (AC), continuous suckling with “male effect” (AC+EM), controlled suckling (Ac), and controlled suckling with “male effect” (Ac+EM). On day 24 PP, the ewes were synchronized with CIDR for 9 days and the “male effect” was started after removing the device (every 6 h for 3 d). From day 7 to 45 PP, blood samples were taken to determine progesterone in plasma in both experiments. A weekly registry was kept of the weight of the ewes and lambs from birthing to weaning (60 d). In experiment 1, it was observed that the ewes under Ac ovulated 52.50%, being different from (p<0.05) those under AC. In experiment 2, the percentage of ovulating ewes was lower in AC (47.37%) as compared against AC+EM, Ac, and Ac+EM (95, 85, and 95 %, respectively). Changes in body weight of both ewes and lambs were not different (p>0.05) among treatments; however, there was an evident weight loss in lambs under Ac+EM. Because of this, it is concluded that controlled suckling reestablishes ovarian activity in Pelibuey ewes, while the “male effect” induces and synchronizes ovulation without affecting body weight of ewes and lambs.

Master thesis

Amamantamiento Efecto macho Ovulación Período postparto Ovejas Pelibuey Suckling Male effect Ovulation Post-partum period Pelibuey ewes Ganadería Maestría CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Muscarinic receptors type 1 and 2 in the preoptic-anterior hypothalamic areas regulate ovulation unequally in the rat oestrous cycle

Yadira L. López Ramírez Kayro López Ramírez ISABEL ARRIETA CRUZ ANGELICA FLORES RAMIREZ LUCIANO MENDOZA GARCES Raúl Alejandro Librado Osorio ROGER GUTIERREZ JUAREZ ROBERTO DOMINGUEZ CASALA MARIA ESTHER CRUZ BELTRAN (2017)

Abstract: Muscarinic receptors types 1 (m1AChR) and 2 (m2AChR) in the preoptic and anterior hypothalamus areas (POA-AHA) were counted, and the effects of blocking these receptors on spontaneous ovulation were analysed throughout the rat oestrous cycle. Rats in each phase of the oestrous cycle were assigned to the following experiments: (1) an immunohistochemical study of the number of cells expressing m1AChR or m2AChR in the POA-AHA and (2) analysis of the effects of the unilateral blockade of the m1AChR (pirenzepine, PZP) or m2AChR (methoctramine, MTC) on either side of the POA-AHA on the ovulation rate. The number of m2AChR-immunoreactive cells was significantly higher at 09:00 h on each day of the oestrous cycle in the POA-AHA region, while no changes in the expression profile of m1AChR protein were observed. The ovulation rate in rats treated with PZP on the oestrous day was lower than that in the vehicle group. Animals treated on dioestrous-1 with PZP or MTC had a higher ovulation rate than those in the vehicle group. In contrast, on dioestrous-2, the MTC treatment decreased the ovulation rate. These results suggest that m1AChR or m2AChR in the POA-AHA could participate in the regulation of spontaneous ovulation in rats.

Article

MEDICINA Y CIENCIAS DE LA SALUD Ciencias médicas Ciencias clínicas Fenómenos fisiológicos reproductivos Reproducción Ovulación Receptores muscarínicos M1 Receptores muscarínicos M2 Reproductive physiological phenomena Reproduction Ovulation Receptor, muscarinic M1 Receptor, muscarinic M2

Somatotropina bovina recombinante (rbST) y su efecto en la inducción de la ovulación en ovejas pelibuey amamantando

HADAILA ZADI MENDEZ ROBLERO (2014)

Tesis (Maestría en Ciencias, especialista en Ganadería).- Colegio de Postgraduados, 2014.

El objetivo de este estudio fue probar la aplicación de somatotropina bovina recombinante (rbST) junto al manejo del amamantamiento, en el restablecimiento de la actividad ovárica postparto en ovejas Pelibuey. Se utilizaron 65 ovejas Pelibuey. Al momento del parto, las ovejas con sus crías fueron asignadas al azar a uno de cuatro tratamientos: amamantamiento continuo (AC; n=18); amamantamiento continuo con somatotropina bovina recombinante (AC+rbST; n=16); amamantamiento controlado (Ac, n=16) y amamantamiento controlado con somatotropina bovina recombinante (Ac+rbST; n=15). Al día 30 postparto, se aplicó un dispositivo intravaginal de liberación de progesterona (CIDR), con una duración de cinco días y 1 mL de prostaglandina F2α (PGF2α), dos días antes del retiro del dispositivo. Las ovejas con rbST, recibieron dos aplicaciones de 250 mg (Boostin-S®, Schering-Plough, México; día 18 y día 33 postparto). No se observaron diferencias (p>0.05) en el porcentaje de ovulación antes y después de la aplicación del CIDR, en el inicio de estro, en el porcentaje de retorno a estro, en la prolificidad y en los cambios de peso en corderos. El porcentaje de presentación de estro, porcentaje de gestación y fecundidad fueron menores (p<0.05) en las ovejas de AC+rbST; 56.26 %, 12.5 %, 0.25±0.17 corderos oveja-1, respectivamente. Los cambios de peso corporal de las ovejas fue menor (p<0.05) en las ovejas de AC+rbST. La aplicación de rbST en ovejas Pelibuey amamantando reduce las manifestaciones de estro y no mejora el porcentaje de gestación, así mismo, reduce el peso corporal de las ovejas, pero no incrementa el peso de los corderos. Independientemente de los tratamientos, inducir la ovulación en ovejas amamantando a los 30 días postparto con CIDR por cinco días y una aplicación de prostaglandina F2α, se logra que el 100 % de las ovejas ovulen. _______________ Recombinant bovine Somatotropin (rbST) AND ITS EFFECT ON OVULATION INDUCTION IN PELIBUEY SHEEP SUCKLING. ABSTRACT: The aim of this study was to evaluate the application of recombinant bovine Somatotropin (rbST) by the management of breastfeeding in the restoration of ovarian activity postpartum in Pelibuey sheep. Sixty-six Pelibuey ewes were used. At parturition, the ewes and their lambs were randomly assigned to one of four treatments: continuous suckling (AC; n=18); continuous suckling with recombinant bovine Somatotropin (AC+rbST; n=16); controlled suckling (Ac, n=16) and controlled suckling with recombinant bovine Somatotropin (Ac+rbST; n=15). At 30 days postpartum, an intravaginal progesterone-releasing device (CIDR) was applied, with a duration of five days and 1 mL of prostaglandin F2α (PGF2α), two days before the removal of the device. Sheep treated with rbST, received two applications of 250 mg (rbST; BOOSTIN-S ®, Schering-Plough, Mexico; day 18 and day 33 postpartum). No differences (p> 0.05) in ovulation percentage before and after the application of CIDR, in the estrus onset, in the percentage return to estrus, in the prolificacy and lamb weight changes were observed. The percentage presence of estrus, pregnancy percentage and fecundity were low (p <0.05) in sheep AC+rbST; 56.26 %, 12.5 %, 0.25 ± 0.17 lambs sheep-1, respectively. Changes in body weight of the sheep was low (p <0.05) in sheep AC+rbST. The application of rbST in Pelibuey ewes suckling reduces the manifestations of estrus, and does not improve the pregnancy percentage, also reduces the body weight of the sheep, but does not increase the weight of the lambs. Regardless of the treatments, to induce ovulation in lactating ewes at 30 days postpartum with CIDR for five days and an application of prostaglandin F2α, is achieved that 100% of ewes ovulating.

Master thesis

Amamantamiento Anestro postparto Ovulación Oveja Pelibuey rbST Suckling Postpartum anoestrus Ovulation Pelibuey ewe Ganadería Maestría CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

The participation of the muscarinic receptors in the preoptic-anterior hypothalamic areas in the regulation of ovulation depends on the ovary

FLORENCIA ADRIANA ESPINOSA VALDEZ MAURA ANGELICA FLORES AGUILAR ISABEL ARRIETA CRUZ MARIO CARDENAS LEON DAVID ROBERTO CHAVIRA RAMIREZ ROBERTO DOMINGUEZ CASALA MARIA ESTHER CRUZ BELTRAN (2016)

Abstract:

Background

Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation.

Methods

Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 μl of saline or atropine solution (62.5 ng) in the left or right POA-AHA; 2) removal (unilateral ovariectomty, ULO) of the left (L-ULO) or right (R-ULO) ovary, and 3) rats microinjected with atropine into the left or right POA-AHA plus L-ULO or R-ULO. The ovulation rate and the number of ova shed were measured during the predicted estrus, as well as the levels of estradiol, FSH and LH during the predicted proestrus and the effects of injecting synthetic LH-releasing hormone (LHRH) or estradiol benzoate (EB).

Results

Atropine in the left POA-AHA decreased both the ovulation rate and estradiol and LH levels on the afternoon of proestrus, also LHRH or EB injection restored ovulation. L- or R-ULO resulted in a lower ovulation rate and smaller number of ova shed, and only injection of LHRH restored ovulation. EB injection at diestrus-2 restored ovulation in animals with L-ULO only. The levels of estradiol, FSH and LH in rats with L-ULO were higher than in animals with unilateral laparotomy. In the group microinjected with atropine in the left POA-AHA, ovulation was similar to that in ULO rats. In contrast, atropine in the right POA-AHA of ULO rats blocked ovulation, an action that was restored by either LHRH or EB injection.

Conclusions: These results indicated that the removal of a single ovary at noon on diestrus-2 day perturbed the neuronal pathways regulating LH secretion, which was mediated by the muscarinic system connecting the right POA-AHA and the ovaries.

Article

MEDICINA Y CIENCIAS DE LA SALUD Ciencias médicas Farmacodinámica Compuestos heterocíclicos Alcaloides solanáceos Alcaloides de belladona Derivados de atropina Atropina Procedimientos quirúrgicos operativos Procedimientos quirúrgicos urogenitales Castración Ovariectomía Ovulación Farmacodynamic Heterocyclic compounds Solanaceous alkaloids Belladonna alkaloids Atropine derivatives Atropine Surgical procedures, operative Urogenital surgical procedures Castration Ovariectomy Ovulation

La reducción en la duración de los tratamientos fotoperiódicos de los machos cabríos, y del tiempo de contacto entre machos y hembras, no disminuyen la eficiencia del efecto macho

JOSÉ LUIS PONCE COVARRUBIAS (2015)

"En los machos cabríos está documentado que los tratamientos fotoperiódicos que incluyen la exposición de 75 días largos (DL) alternados con el fotoperiodo natural correspondiente a días cortos (DC) crecientes, son eficientes para inducir una intensa actividad sexual durante el periodo de reposo sexual natural. Además, cuando estos machos foto-estimulados son puestos en contacto con hembras anovulatorias durante al menos 15 días estimulan su actividad estral y ovulatoria.Sin embargo, no se conoce si los tratamientos de DL menores a 75 días reducen la respuesta sexual de los machos a dicho tratamiento, así como su capacidad para estimular la actividad ovulatoria de las hembras anéstricas durante el efecto macho. Asimismo, no se conoce si un tiempo de contacto macho-hembra menor a 15 días reduce la respuesta ovulatoria. Por ello, en la presente tesis se llevaron a cabo 3 experimentos para aclarar los planteamientos anteriores"

"In male goats is documented that the photoperiodic treatments that include the exposure to 75 long days (LD) alternating with short days (DC) corresponding to increasing natural photoperiod, are efficient to induce an intense sexual activity during the natural sexual rest. Furthermore, when these males photo-stimulated are contacted with anovulatory females for at least 15 days, stimulate estrus and ovulatory activity. However, it isn´t known whether treatments of less than 75 days DL reduce male sexual response to treatment, as well as its ability to stimulate ovulatory activity of anestrus females during the male effect. Also isn´t known whether time male-female contact less than 15 days reduces the ovulatory response. Therefore, in this thesis were conducted three experiments to clarify the above statements.In the study 1, two experiments were conducted to determine i) the decrease in DL treatments at 45, 30, or 15 days, does not reduce the sexual response of male goats to treatment; ii) determine whether photo-stimulated males 45 or 30 DL induce ovulation in anovulatory goats activity. In both experiments females and males local goats from the Comarca Lagunera, located in the Mexican subtropics (26°N) were used. In experiment 1 was used 25 adult goats. A group of males (n=5) was exposed to the photoperiod natural variations, while 4 groups (n=5/group) were exposed to 16 hours of light per day for 75, 45, 30, or 15 DL artificial. In the 4 groups, photoperiodic treatments ended on January 15th. Plasma concentrations of"

Doctoral thesis

Estacionalidad reproductiva Testosterona Comportamiento sexual Efecto macho Duración del contacto Ovulación CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

La reducción del tiempo de contacto diario entre machos y hembras no disminuye las respuestas ovulatoria y reproductiva de las cabras expuestas al efecto macho durante el anestro

MARIE CHRISTINE ALINE BEDOS (2013)

"La introducción de un macho cabrío o un carnero en un grupo de hembras anovulatorias estimula el comportamiento de estro y la ovulación en los primeros 5 días de contacto con los machos. Esta técnica de bioestimulación sexual se conoce como efecto macho. Las respuestas ovulatoria y reproductiva de las hembras expuestas al efecto macho puede variar con la intensidad del comportamiento sexual de los machos. El uso de machos cabríos inducidos a un comportamiento sexual intenso durante el ix periodo de reposo sexual al someterlos a un tratamiento de días largos - machos foto-estimulados- incrementa considerablemente los porcentajes de cabras que ovulan, se gestan y paren al someterlas al efecto macho (Flores et al., 2000; Delgadillo et al., 2002). La duración del tiempo de contacto entre ambos sexos, es otro factor que influye sobre la respuesta ovulatoria de las hembras expuestas al efecto macho. En ovejas, es necesario mantener el contacto entre machos y hembras 24 h por día durante 13 días para que ovule la mayoría de las hembras (61 %; Signoret et al., 1982). En cambio, Rivas-Muñoz et al. (2007) demostraron que en las cabras locales de la Comarca Lagunera, la duración de contacto con machos cabríos fotoestimulados puede ser reducida a 16 h por día sin que se disminuya la respuesta estral de las hembras. Sin embargo, no se sabe si el tiempo de contacto entre machos cabríos foto-stimulados y cabras anéstricas se puede reducir aun más, sin disminuir la respuesta ovulatoria y reproductiva de las hembras. Por lo tanto, se realizaron 2 estudios para determinar si una reducción del tiempo de contacto diario entre los sexos no disminuye la respuesta ovulatoria y reproductiva de las cabras."

"The introduction of a buck or ram in a group of anovulatory females stimulates estrus behavior and ovulation within the first 5 days of contact with males. This technique of biostimulation is known as the male effect. Ovulatory and reproductive responses of females exposed to the male effect may vary with the intensity of male sexual behavior. The use of bucks induced to an intense sexual behavior during the non-breeding season by subjecting them to a long-day treatment -photo-stimulated males- increases significantly the percentages of goats ovulating, getting pregnant and giving birth in response to the male effect (Flores et al., 2000; Delgadillo et al., 2002). The duration of contact between males and females is another factor that modulates the response of females exposed to the male effect. In sheep, it is necessary to maintain contact between males and females 24 h per day for 13 days so that most females ovulate (61%; Signoret et al., 1982). On the contrary, Rivas-Muñoz et al. (2007) demonstrated that in local goats from the “Comarca Lagunera”, reducing contact with photo-stimulated bucks from 24 h to 16 h per day did not reduce the response of females submitted to the male effect. However, it remains unknown if the duration of contact between photostimuladed bucks and anestrous goats can be further reduced without decreasing the ovulatory and reproductive responses of females. Therefore, two studies were carried out to determine whether a decrease of the duration of contact between sexes does not reduce the ovulatory and reproductive xvi responses of anestrous goats exposed to the male effect. Since the decrease of the duration of contact to 4 daily hours did not reduce the sexual and reproductive response of females, in a third study, we determined whether the photo-stimulated bucks were able to stimulate 3 groups of females being in contact with them 4 daily hours."

Doctoral thesis

Efecto macho Duración de contacto Ovulación Olfato Proporción macho-hembra CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Estrogen receptors alpha and beta in POA-AHA region regulate asymmetrically ovulation

ISABEL ARRIETA CRUZ Raúl Alejandro Librado Osorio ANGELICA FLORES RAMIREZ LUCIANO MENDOZA GARCES DAVID ROBERTO CHAVIRA RAMIREZ MARIO CARDENAS LEON ROGER GUTIERREZ JUAREZ ROBERTO DOMINGUEZ CASALA MARIA ESTHER CRUZ BELTRAN (2019)

We examined the role of the estrogen receptors alpha (ERα) and beta (ERβ) in of the preoptic-anterior hypothalamic area (POA-AHA) in the regulation of ovulation in rats. The number of ERα- and ERβ-immunoreactive (-ir) cells was determined at 09:00, 13:00, and 17:00 h of each stage of the estrous cycle in intact rats. Additionally, the effects of blocking ERα and ERβ on ovulation rate at 09:00 h on diestrus-2 or proestrus day through the microinjection of methyl-piperidino-pyrazole (MPP) or cyclofenil in either side of POA-AHA were evaluated. The number of ERα-ir and ERβ-ir cells in POA-AHA varied in each phase of estrous cycle. Either MPP or cyclofenil in the right side of POA-AHA on diestrus-2 day reduced the ovulation rate, while at proestrus day it was decreased in rats treated in either side with MPP, and in those treated with cyclofenil in the left side. MPP or cyclofenil produced a decrease in the surge of luteinizing hormone levels (LH) and an increase in progesterone and follicle stimulating hormone (FSH). Replacement with synthetic luteinizing hormone-releasing hormone in non-ovulating rats treated with MPP or cyclofenil restored ovulation. These results suggest that activation of estrogen receptors on the morning of diestrus-2 and proestrus day asymmetrically regulates ovulation and appropriately regulates the secretion of FSH and progesterone in the morning and afternoon of proestrus day. This ensures that both, the preovulatory secretion of LH and ovulation, occur at the right time.

Article

MEDICINA Y CIENCIAS DE LA SALUD Ciencias médicas Ciencias Clínicas Fenómenos fisiológicos reproductivos Reproducción Ovulación Reproductive phsysiological phenomena Reproduction Ovulation

The participation of the muscarinic receptors in the preoptic-anterior hypothalamic areas in the regulation of ovulation depends on the ovary

FLORENCIA ADRIANA ESPINOSA VALDEZ MAURA ANGELICA FLORES AGUILAR ISABEL ARRIETA CRUZ MARIO CARDENAS LEON DAVID ROBERTO CHAVIRA RAMIREZ ROBERTO DOMINGUEZ CASALA MARIA ESTHER CRUZ BELTRAN (2016)

Abstract:

Background

Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation.

Methods

Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 μl of saline or atropine solution (62.5 ng) in the left or right POA-AHA; 2) removal (unilateral ovariectomty, ULO) of the left (L-ULO) or right (R-ULO) ovary, and 3) rats microinjected with atropine into the left or right POA-AHA plus L-ULO or R-ULO. The ovulation rate and the number of ova shed were measured during the predicted estrus, as well as the levels of estradiol, FSH and LH during the predicted proestrus and the effects of injecting synthetic LH-releasing hormone (LHRH) or estradiol benzoate (EB).

Results

Atropine in the left POA-AHA decreased both the ovulation rate and estradiol and LH levels on the afternoon of proestrus, also LHRH or EB injection restored ovulation. L- or R-ULO resulted in a lower ovulation rate and smaller number of ova shed, and only injection of LHRH restored ovulation. EB injection at diestrus-2 restored ovulation in animals with L-ULO only. The levels of estradiol, FSH and LH in rats with L-ULO were higher than in animals with unilateral laparotomy. In the group microinjected with atropine in the left POA-AHA, ovulation was similar to that in ULO rats. In contrast, atropine in the right POA-AHA of ULO rats blocked ovulation, an action that was restored by either LHRH or EB injection.

Conclusions: These results indicated that the removal of a single ovary at noon on diestrus-2 day perturbed the neuronal pathways regulating LH secretion, which was mediated by the muscarinic system connecting the right POA-AHA and the ovaries.

Article

MEDICINA Y CIENCIAS DE LA SALUD Ciencias médicas Farmacodinámica Compuestos heterocíclicos Alcaloides solanáceos Alcaloides de belladona Derivados de atropina Atropina Procedimientos quirúrgicos operativos Procedimientos quirúrgicos urogenitales Castración Ovariectomía Ovulación Farmacodynamic Heterocyclic compounds Solanaceous alkaloids Belladonna alkaloids Atropine derivatives Atropine Surgical procedures, operative Urogenital surgical procedures Castration Ovariectomy Ovulation

Las cabras en contacto restringido con machos adelantan el inicio de la pubertad

SERGIO RAMIREZ GOMEZ (2014)

"El objetivo del actual estudio fue determinar si la presencia restringida del macho cabrío adelanta el inicio de la pubertad de las hembras caprinas del subtrópico mexicano. Las hembras nacieron el 10 de enero ± 2 días, a los 3 días de edad fueron separadas de sus madres. Posteriormente, fueron criadas artificialmente con leche de cabra hasta los 40 días de edad. A esta edad promedio fueron asignadas al azar a tres grupos. El primer grupo de hembras (n = 9) fue aislado de machos y de otras hembras de su misma especie. El segundo grupo (n = 10) tuvo contacto visual, auditivo, olfativo y táctil restringido permanente con 2 machos vasectomizados y la cópula no fue permitida mediante una malla ciclónica. El tercer grupo (n = 10) tuvo contacto visual, auditivo, olfativo y táctil total permanente con 2 machos vasectomizados. Los machos vasectomizados permanecieron en contacto restringido y total con las hembras a partir del destete. La primera ovulación se consideró como el inicio de la pubertad, la cual fue detectada mediante la concentración de progesterona plasmática (≥ 1 ng/ml), en al menos dos muestreos sanguíneos consecutivos. La proporción de hembras que iniciaron la pubertad se analizó con la prueba Chi-cuadrada. La primera ovulación no difirió significativamente entre las hembras en contacto restringido y total con machos (277 ± 5.0 días y 280 ± 8.0 días, respectivamente; P = 0.9). Mientras que las hembras aisladas de machos fue 23 días después (P = 0.05). La proporción de hembras que inició la pubertad de acuerdo a la edad en días no difirió entre los grupos de hembras en contacto restringido y total con machos o en aquellas aisladas de ellos (9/10 90%; 9/10 90%; 9/9 100%, respectivamente; P = 0.6). El peso y la condición corporal al inicio de la pubertad no difirió entre las hembras en contacto restringido y total con machos (20.8 ± 0.7 kg y 2.5 ± 0.05; 18.7 ± 0.7 kg y 2.3 ± 0.1; P = 0.3 y P = 0.09, respectivamente). Mientras que en las hembras aisladas de machos registraron mayor peso en comparación a los otros 2 grupos de hembras (26.6 ± 1.3 kg y 2.8 ± 0.08; P = 0.01). Se concluye que las cabras prepúberes en contacto restringido o total con machos adelantan el inicio de la pubertad."

"The objective of this study was to determine whether pre-pubertal goats in restricted contact or total with males advance the onset of puberty, comparing with those remained isolated from males. Female kids were born in January 10th ± 2 days, and were separated from their mothers at 3 days of age. Subsequently, the females were artificially reared with goat milk until 40 days of age. At this average age were randomly assigned into three groups. The first group of females (n = 9) was isolated from males and other females of the same species. The second group (n = 10) had visual, auditory, olfactory and tactile contact with 2 vasectomized males, and intromission were not allowed throughout a fence. The third group (n = 10), had visual, auditory, olfactory and tactile total contact with 2 vasectomized males. The vasectomaized males remained with females from May until December. The first ovulation was considered as the onset of puberty, which was detected by means of the plasma progesterone concentration (≥ 1 ng/ml) in at least two consecutive blood samples. The proportion of females to the onset of puberty was analyzed using a Chi-square test. The first ovulation detected did not differ significantly between females in restricted contact with males and those in full contact with them (277 ± 5.0 days and 280 ± 8.0 days, respectively; P = 0.9). While the first ovulation detected in females isolated from males was 23 days late. In this group the onset puberty was at 300 ± 5.0 days (P = 0.05), compared with other 2 female groups. The proportion of females to the onset of puberty by age in days did not differ between females in restricted contact, full contact permanent with males or those isolated from them (9/10 90%, 9/10 90%, 9/9 100%, respectively; P = 0.6). The body weight and body condition score to the onset of puberty did not differ x between females in restricted and full contact of them (20.8 ± 0.7 kg and 2.5 ± 0.05; 18.7 ± 0.7 kg and 2.3 ± 0.1; P = 0.3 and P = 0.09, respectively). While those isolated from males were significantly different from other 2 groups of females (26.6 ± 1.3 kg and 2.8 ± 0.08; P = 0.01). In conclusion, pre-pubertal goats in restricted contact or total with males advance the onset of puberty"

Master thesis

Cabras Pubertad Ovulación CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA