Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion
Marked sexual and ontogenic differences have been described in gonadotropin regulation in the rat. These could arise from events occurring both at the hypothalamic or hypophyseal levels. The present experiments were designed to evaluate the capacity of the hypothalamus in releasing GnRH in vitro, ba...
Guardado en:
| Autores principales: | , , , , , |
|---|---|
| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00379727_v217_n4_p445_LacauMengido |
| Aporte de: |
| id |
todo:paper_00379727_v217_n4_p445_LacauMengido |
|---|---|
| record_format |
dspace |
| spelling |
todo:paper_00379727_v217_n4_p445_LacauMengido2023-10-03T14:48:15Z Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion Lacau-Mengido, I.M. Iglesias, A.G. Díaz-Torga, G. Thyssen-Cano, S. Libertun, C. Becú-Villalobos, D. gonadorelin sex hormone androgen therapy animal experiment animal model article controlled study embryo development gonadotropin release hormonal regulation hormone release hypothalamus hypothalamus hypophysis adrenal system in vitro study membrane depolarization neurotransmitter release nonhuman ontogeny rat Aging Animals Animals, Newborn Female Follicle Stimulating Hormone Gonadotropin-Releasing Hormone Hypothalamus Luteinizing Hormone Male Potassium Rats Rats, Sprague-Dawley Sex Characteristics Testosterone Animalia Marked sexual and ontogenic differences have been described in gonadotropin regulation in the rat. These could arise from events occurring both at the hypothalamic or hypophyseal levels. The present experiments were designed to evaluate the capacity of the hypothalamus in releasing GnRH in vitro, basally and in response to depolarization with KCl, during ontogeny in the rat. To that end we chose two well-defined developmental ages that differ markedly in sexual and ontogenic characteristics of gonadotropin regulation, 15 and 30 days. We compared GnRH release from hypothalami of females, neonatal androgenized females and males. Mediobasal hypothalami were perifused in vitro, and GnRH measured in the effluent. Basal secretion of the decapeptide increased with age in the three groups with no sexual differences encountered. When studying GnRH release induced by membrane depolarization, no differences within sex or age were encountered. On the other hand FSH serum levels decreased with age in females and increased in males, and in neonatal androgenized females followed a similar pattern to that of females. LH levels were higher in infantile females than in age-matched males or androgenized females. Such patterns of gonadotropin release were therefore not correlated to either basal or K+-induced GnRH release from the hypothalamus. We conclude that sexual and ontogenic differences in gonadotropin secretion in the developing rat era not dependent on the intrinsic capability of the hypothalamus to release GnRH in response to membrane depolarization. The hormonal differences observed during development and between sexes are probably related to differences in the sensitivity of the GnRH neuron to specific secretagogue and neurotransmitter regulation, and/or to differences in hypophyseal GnRH receptors and gonadotrope sensitivity. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00379727_v217_n4_p445_LacauMengido |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
gonadorelin sex hormone androgen therapy animal experiment animal model article controlled study embryo development gonadotropin release hormonal regulation hormone release hypothalamus hypothalamus hypophysis adrenal system in vitro study membrane depolarization neurotransmitter release nonhuman ontogeny rat Aging Animals Animals, Newborn Female Follicle Stimulating Hormone Gonadotropin-Releasing Hormone Hypothalamus Luteinizing Hormone Male Potassium Rats Rats, Sprague-Dawley Sex Characteristics Testosterone Animalia |
| spellingShingle |
gonadorelin sex hormone androgen therapy animal experiment animal model article controlled study embryo development gonadotropin release hormonal regulation hormone release hypothalamus hypothalamus hypophysis adrenal system in vitro study membrane depolarization neurotransmitter release nonhuman ontogeny rat Aging Animals Animals, Newborn Female Follicle Stimulating Hormone Gonadotropin-Releasing Hormone Hypothalamus Luteinizing Hormone Male Potassium Rats Rats, Sprague-Dawley Sex Characteristics Testosterone Animalia Lacau-Mengido, I.M. Iglesias, A.G. Díaz-Torga, G. Thyssen-Cano, S. Libertun, C. Becú-Villalobos, D. Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion |
| topic_facet |
gonadorelin sex hormone androgen therapy animal experiment animal model article controlled study embryo development gonadotropin release hormonal regulation hormone release hypothalamus hypothalamus hypophysis adrenal system in vitro study membrane depolarization neurotransmitter release nonhuman ontogeny rat Aging Animals Animals, Newborn Female Follicle Stimulating Hormone Gonadotropin-Releasing Hormone Hypothalamus Luteinizing Hormone Male Potassium Rats Rats, Sprague-Dawley Sex Characteristics Testosterone Animalia |
| description |
Marked sexual and ontogenic differences have been described in gonadotropin regulation in the rat. These could arise from events occurring both at the hypothalamic or hypophyseal levels. The present experiments were designed to evaluate the capacity of the hypothalamus in releasing GnRH in vitro, basally and in response to depolarization with KCl, during ontogeny in the rat. To that end we chose two well-defined developmental ages that differ markedly in sexual and ontogenic characteristics of gonadotropin regulation, 15 and 30 days. We compared GnRH release from hypothalami of females, neonatal androgenized females and males. Mediobasal hypothalami were perifused in vitro, and GnRH measured in the effluent. Basal secretion of the decapeptide increased with age in the three groups with no sexual differences encountered. When studying GnRH release induced by membrane depolarization, no differences within sex or age were encountered. On the other hand FSH serum levels decreased with age in females and increased in males, and in neonatal androgenized females followed a similar pattern to that of females. LH levels were higher in infantile females than in age-matched males or androgenized females. Such patterns of gonadotropin release were therefore not correlated to either basal or K+-induced GnRH release from the hypothalamus. We conclude that sexual and ontogenic differences in gonadotropin secretion in the developing rat era not dependent on the intrinsic capability of the hypothalamus to release GnRH in response to membrane depolarization. The hormonal differences observed during development and between sexes are probably related to differences in the sensitivity of the GnRH neuron to specific secretagogue and neurotransmitter regulation, and/or to differences in hypophyseal GnRH receptors and gonadotrope sensitivity. |
| format |
JOUR |
| author |
Lacau-Mengido, I.M. Iglesias, A.G. Díaz-Torga, G. Thyssen-Cano, S. Libertun, C. Becú-Villalobos, D. |
| author_facet |
Lacau-Mengido, I.M. Iglesias, A.G. Díaz-Torga, G. Thyssen-Cano, S. Libertun, C. Becú-Villalobos, D. |
| author_sort |
Lacau-Mengido, I.M. |
| title |
Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion |
| title_short |
Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion |
| title_full |
Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion |
| title_fullStr |
Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion |
| title_full_unstemmed |
Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion |
| title_sort |
effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion |
| url |
http://hdl.handle.net/20.500.12110/paper_00379727_v217_n4_p445_LacauMengido |
| work_keys_str_mv |
AT lacaumengidoim effectofstageofdevelopmentandsexongonadotropinreleasinghormonesecretionininvitrohypothalamicperifusion AT iglesiasag effectofstageofdevelopmentandsexongonadotropinreleasinghormonesecretionininvitrohypothalamicperifusion AT diaztorgag effectofstageofdevelopmentandsexongonadotropinreleasinghormonesecretionininvitrohypothalamicperifusion AT thyssencanos effectofstageofdevelopmentandsexongonadotropinreleasinghormonesecretionininvitrohypothalamicperifusion AT libertunc effectofstageofdevelopmentandsexongonadotropinreleasinghormonesecretionininvitrohypothalamicperifusion AT becuvillalobosd effectofstageofdevelopmentandsexongonadotropinreleasinghormonesecretionininvitrohypothalamicperifusion |
| _version_ |
1807321409039368192 |