RESUMEN
There is considerable evidence of the neuroendocrine control involved in luteal regression in the rat. In addition, circulating prolactin (PRL), which increases during the night before parturition, may gain access to the coeliac ganglion (CG), indirectly impacting the physiology of the ovary because of the known connection between the CG and the ovary via the superior ovarian nerve (SON). In this work we investigated in the CG-SON-ovary system and whether PRL added to the CG has an impact, indirectly via the SON, on luteal regression on Day 21 of pregnancy. The system was incubated without (control) or with PRL added to the CG. We measured the ovarian release of progesterone (P), oestradiol and prostaglandin F2 alpha (PGF2α) by radioimmunoassay, and nitrites (NO) by the Griess method. Luteal mRNA expression of 3ß-hydroxysteroid dehydrogenase (3ß-HSD), 20α-HSD, aromatase, inducible nitric oxide synthase (iNOS) and apoptosis regulatory factors was analysed by reverse transcription-polymerase chain reaction. P release, the expression of Bcl-2 and the Bcl-2:Bax ratio was lower than control preparations, while the expression of 20α-HSD and the release of NO and PGF2α were higher in the experimental group. In conclusion, PRL acts at the CG and, by a neural pathway, modulates luteal function at the end of pregnancy.
Asunto(s)
Cuerpo Lúteo/inervación , Ganglios Simpáticos/efectos de los fármacos , Luteólisis/efectos de los fármacos , Ovario/inervación , Prolactina/farmacología , 20-alfa-Hidroxiesteroide Deshidrogenasa/genética , 20-alfa-Hidroxiesteroide Deshidrogenasa/metabolismo , 3-Hidroxiesteroide Deshidrogenasas/genética , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Animales , Aromatasa/genética , Aromatasa/metabolismo , Cuerpo Lúteo/enzimología , Cuerpo Lúteo/patología , Dinoprost/metabolismo , Estradiol/metabolismo , Femenino , Ganglios Simpáticos/fisiología , Edad Gestacional , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Nitritos/metabolismo , Ovario/metabolismo , Embarazo , Progesterona/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas Sprague-Dawley , Factores de Tiempo , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
OBJECTIVE: To investigate whether cholinergic ganglionic stimulus modifies the release of gonadotropin-releasing hormone (GnRH), catecholamines, and progesterone at the ovarian level. DESIGN: Animal study. SETTING: University animal laboratory. ANIMAL(S): Six to eight virgin adult Holtzman rats. INTERVENTION(S): Superior mesenteric ganglion-ovarian nerve plexus-ovary system removed and placed in one cuvette with two compartments, with acetylcholine added to the ganglion in the experimental group. MAIN OUTCOME MEASURE(S): Measurement of ovarian liquid obtained from catecholamines by high-performance liquid chromatography; measurement of progesterone (P(4)), GnRH, and luteinizing hormone (LH) by radioimmunoassay; and measurement of gene expression of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and 20α-hydroxysteroid dehydrogenase (20α-HSD) by reverse-transcriptase polymerase chain reaction (RT-PCR). RESULT(S): The study focused on the estrus and diestrus II (DII) stages. On the estrus days, the release of GnRH, NA, and 20α-HSD increased, while P(4) and 3ß-HSD decreased. On the DII days, GnRH, P(4), and 3ß-HSD increased, while 20α-HSD and NA decreased. The ovarian liquid with GnRH showed biologic activity, namely, an increase in LH release during the DII stage and a decrease during the estrus stage. CONCLUSION(S): Neural stimulus from the superior mesenteric ganglion influences the release of NA, adrenaline, and GnRH. We also have demonstrated that these neurotransmitters participate in the atretogenic processes of the ovary, thus providing evidence of the necessity of the sympathetic neural pathway.
Asunto(s)
Catecolaminas/metabolismo , Ganglios Simpáticos/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Ovario/inervación , Ovario/metabolismo , Progesterona/metabolismo , Receptores Colinérgicos/metabolismo , 20-alfa-Hidroxiesteroide Deshidrogenasa/genética , 20-alfa-Hidroxiesteroide Deshidrogenasa/metabolismo , 3-Hidroxiesteroide Deshidrogenasas/genética , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Acetilcolina/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Diestro/metabolismo , Estro/metabolismo , Femenino , Ovario/enzimología , ARN Mensajero/metabolismo , Radioinmunoensayo , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de TiempoRESUMEN
The aims of this work were to investigate if oestradiol 10(-8)M in the incubation media of either the ovary alone (OV) or the ganglion compartment of an ex vivo coeliac ganglion-superior ovarian nerve-ovary system (a) modifies the release of ovarian progesterone (P4) and oestradiol (E2) on dioestrus II, and (b) modifies the ovarian gene expression of 3ß-HSD and 20α-HSD enzymes and markers of apoptosis. The concentration of ovarian P4 release was measured in both experimental schemes, and ovarian P4 and E2 in the ex vivo system by RIA at different times. The expression of 3ß-hydroxysteroid dehydrogenase, 20α-hydroxysteroid dehydrogenase and antiapoptotic bcl-2 and proapoptotic bax by RT-PCR were determined. E2 added in the coeliac ganglion caused an increase in the ovarian release of the P4, E2 and 3ß-HSD, while in the ovary incubation alone it decreased P4 and 3ß-HSD but increased and 20α-HSD and bax/bcl-2 ratio. It is concluded that through a direct effect on the ovary, E2 promotes luteal regression in DII rats, but the addition of E2 in the coeliac ganglion does not have the same effect. The peripheral nervous system, through the superior ovarian nerve, has a protective effect against the apoptotic mechanism on DII.
Asunto(s)
Apoptosis/efectos de los fármacos , Diestro , Estradiol/farmacología , Ganglios Simpáticos/efectos de los fármacos , Ovario , 20-alfa-Hidroxiesteroide Deshidrogenasa/genética , 20-alfa-Hidroxiesteroide Deshidrogenasa/metabolismo , 3-Hidroxiesteroide Deshidrogenasas/genética , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Animales , Estradiol/biosíntesis , Estradiol/metabolismo , Femenino , Ganglios Simpáticos/metabolismo , Ovario/efectos de los fármacos , Ovario/inervación , Ovario/metabolismo , Progesterona/metabolismo , Ratas , Proteína X Asociada a bcl-2/metabolismo , Proteína Letal Asociada a bcl/biosíntesis , Proteína Letal Asociada a bcl/metabolismoRESUMEN
There is evidence suggesting that estradiol (E(2)) regulates the physiology of the ovary and the sympathetic neurons associated with the reproductive function. The objective of this study was to investigate the effect of E(2) on the function of late pregnant rat ovaries, acting either directly on the ovarian tissue or indirectly via the superior ovarian nerve (SON) from the celiac ganglion (CG). We used in vitro ovary (OV) or ex vivo CG-SON-OV incubation systems from day 21 pregnant rats. Various concentrations of E(2 )were added to the incubation media of either the OV alone or the ganglion compartment of the CG-SON-OV system. In both experimental schemes, we measured the concentration of progesterone in the OV incubation media by radioimmunoassay at different times. Luteal messenger RNA (mRNA) expression of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and 20α-hydroxysteroid dehydrogenase (20α-HSD) enzymes, respectively, involved in progesterone synthesis and catabolism, and of antiapoptotic B-cell lymphoma 2 (Bcl-2) and proapoptotic Bcl-2-associated X protein (Bax), were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) at the end of the incubation period. Estradiol added directly to the OV incubation or to the CG of the CG-SON-OV system caused a decline in the concentration of progesterone accumulated in the incubation media. In addition, E(2), when added to the OV incubation, decreased the expression of 3ß-HSD and the ratio of Bcl-2/Bax. We conclude that through a direct effect on the OV, E(2) favors luteal regression at the end of pregnancy in rats, in association with neural modulation from the CG via the SON.
Asunto(s)
Cuerpo Lúteo/efectos de los fármacos , Estradiol/farmacología , Ganglios Simpáticos/efectos de los fármacos , Luteólisis/efectos de los fármacos , Ovario/efectos de los fármacos , Progesterona/metabolismo , 20-alfa-Hidroxiesteroide Deshidrogenasa/genética , 20-alfa-Hidroxiesteroide Deshidrogenasa/metabolismo , 3-Hidroxiesteroide Deshidrogenasas/genética , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Animales , Cuerpo Lúteo/enzimología , Cuerpo Lúteo/inervación , Cuerpo Lúteo/fisiología , Femenino , Ganglios Simpáticos/enzimología , Ganglios Simpáticos/fisiología , Técnicas In Vitro , Luteólisis/fisiología , Ovario/enzimología , Ovario/inervación , Ovario/fisiología , Embarazo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Mensajero/química , ARN Mensajero/genética , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
The ovarian function is controlled by endocrine factors and neural influence. In late pregnant rat, androstenedione, from the coeliac ganglion, has a luteotrophic effect in the ex vivo coeliac ganglion-superior ovarian nerve-ovary system. In this work we investigate the presence of androgen receptors in the coeliac ganglion of late pregnant rats by immunohistochemistry. We also explore, from a physiological point of view, the potential participation of these receptors in the androstenedione ganglionic action on progesterone release and metabolism, as well as on nitrites release in the ovary compartment. The coeliac ganglion was isolated after being fixed in situ and immunohistochemistry was performed. In the system, three experimental groups were used with the addition of (a) androstenedione, (b) flutamide, and (c) androstenedione plus flutamide in the ganglion compartment. Progesterone and nitrite concentrations were determined in the ovary compartment at different incubation times. Corpora lutea samples isolated at the end of incubation were used to determine the expressions and activities of the progesterone synthesis (3beta-hydroxysteroid-dehydrogenase, 3beta-HSD) and degradation (20alpha-hydroxysteroid-dehydrogenase, 20alpha-HSD) enzymes. Immunohistochemistry revealed cytoplasmatic androgen receptor immunoreactivity in neural somas in the coeliac ganglion. In the coeliac ganglion-superior ovarian nerve-ovary system, androstenedione addition increased 3beta-HSD and decreased 20alpha-HSD, showed a tendency to decrease 20alpha-HSD expression, and increased nitrites release in relation to control. Androstenedione plus flutamide decreased progesterone and nitrites release in relation to the androstenedione group. This work demonstrates the presence of androgen receptors in neurons of celiac ganglion and provides evidence for the luteotrophic action of androstenedione via a neural pathway that may be mediated by these receptors.