The effect of clomiphene and cyclofenil upon pituitary LH and hypothalamic LH-Releasing-Factor content in the female rat

Zusammenfassung Der Effekt von Clomifenhydrogencitrat und von Cyclofenil auf den LH-Gehalt der Hypophyse und den LH-RF-Gehalt des Hypothalamus wurde an kastrierten, weiblichen Ratten untersucht, die mit Östradiol und Progesteron blockiert worden waren. Während die Injektion von Cyclofenil im Dosisbereich von 100 bis 600 g/Tier zu einem Abfall von sowohl LH als auch LH-RF führte, konnte bei Verabreichung von Clomifen nur bei der Gabe von 25 g/Tier eine signifikante Herabsetzung von LH und LH-RF beobachtet werden.     

FSH-releasing effect of clomiphene in the female rat

Zusammenfassung Der Effekt von Clomifendihydrogenzitrat auf den FSH-Release der Ratte wurde untersucht. Die i.v. Injektion von 300 bzw. 600 µg Clomifendihydrogenzitrat/Tier führte bei oophorektomierten, weiblichen Ratten, die mit Östradiol und Progesteron blokkiert worden waren, zu einer signifikanten Erhöhung der FSH-Aktivität im Plasma. Eine Beeinträchtigung des FSH-Nachweises durch noch im Plasma befindliches Clomifendihydrogencitrat konnte ausgeschlossen werden.     

DNA synthesis in the pituitary gland of the rat: effect of sulpiride and clomiphene.

Sulpiride administration to rats releases prolactin and increases DNA replication in the anterior pituitary gland. Clomiphene prevents the stimulation of DNA synthesis produced by sulpiride, but does not affect prolactin release from the gland. These findings suggest that the intracellular prolactin content of the anterior pituitary gland plays a role in the regulation of DNA synthesis through a mechanism mediated by oestrogens.     

An early effect of testosterone propionate upon hypothalamic function in the neonatal rat

Rats treated neonatally with testosterone propionate exhibit a reduced uterine growth response to estradiol administration prepubertally. This androgen-induced impairment is the consequence of developmental effects on both the ovary and the hypothalamic-pituitary complex, although the latter is the more sensitive.     

Effect of hypothalamic lesions on MSH content of the intermediate lobe of the pituitary gland in the rat

Zusammenfassung Es wird gezeigt, dass Elektrokoagulation in verschiedenen Teilen des basalen Hypothalamus einen Einfluss auf den Melanophorenhormongehalt im Hypophysenzwischenlappen der Ratte hat.     

The influence of oestrogen and thyroid on the pituitary and blood content of FSH and LH

Résumé L'effet de l'administration du «Benzoate d'stradiol» et des hormones thyroïdales seuls ou en combinaison sur le FSH et LH contenus dans le sang et les hypophyses des femelles rats castrés a été étudié. Il a été trouvé que l'stradiol et l'extract de la thyroïde quand ils sont administrés seuls produisent une baisse, dans le sang, du FSH et une hausse du LH. L'administration combinée de ces deux hormones renforce cet effet.     

DNA synthesis in the pituitary gland of the rat: Effect of sulpiride and clomiphene

Summary Sulpiride administration to rats releases prolactin and increases DNA replication in the anterior pituitary gland. Clomiphene prevents the stimulation of DNA synthesis produced by sulpiride, but does not affect prolactin release from the gland. These findings suggest that the intracellular prolactin content of the anterior pituitary gland plays a role in the regulation of DNA synthesis through a mechanism mediated by oestrogens.This work was supported by PLAMIRH 99.178.1.78, by the Consejo Nacional de Investigaciones Científicas y Técnicas and by the Comisión Nacional de Energía Atómica (Argentina). We are grateful to Dr P. Scacchi for performing the radioimmunoassay and to Prof. C. J. Gómez for the opportunity to perform this work.     

The effect of reserpine upon gastrointestinal serotonin in the sprague-dawley rat

Zusammenfassung Der Serotoningehalt der Schleimhaut von 14 gastrointestinalen Geweben von Sprague-Dawley Rattenmännchen und -weibchen wurde nach i.p. Injektion von Reserpin spektrophotofluorimetrisch gemessen. Die Verteilung von Serotonin im Magendarmkanal 4 und 16 h nach der Reserpininjektion zeigte, dass Magengewebe und Kolongewebe nach 16 h mehr entleert waren als nach 4 h, während Dünndarm und Appendix nach 4 h mehr entleert waren als nach 16 h.

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This research was supported by U.S.P.H.S. grant No. AM 07909, toJ. H. Thompson.     

The effect of continuously cooling the hypothalamic preoptic area on antibody titre in the rat

Summary Continuous cooling of the hypothalamic preoptic area for 5 days, as well as sublethal infection withSalmonella enteritidis, increased the titre of antibodies against sheep erythrocytes, suggesting that the febrile response stimulates the humoral immune response.We thank Dr W. Mannheim from the Institute of Hygiene for kindly supplying the cultures ofS. enteritidis. This work was supported by the Schwerpunktprogramm Temperaturregulation und-adaptation of the Deutsche Forschungsgemeinschaft.     

Stimulation of pituitary LH and FSH secretion after immunoneutralization of endogenous substance P in the cycling rat]

In the cycling female Rat, administration of substance P antisera performed at noon on the proestrous day provokes a significant increase in LH and FSH serum level, right before or after the preovulatory surges, but had no effect on its occurrence or magnitude. These results suggest that substance P has a normal physiological inhibitory role in gonadotropin regulation.     

Suppression by LH-releasing hormone (LHRH) of the augmenting effect of estradiol on the secretion of LH and FSH by the rat pituitary gland

Summary Estradiol sensitizes the pituitary gland for the gonadotropin-releasing activity of LHRH. LHRH desensitizes the pituitary gland and does so in a dose-dependent manner. Moreover, LHRH dose-dependently suppresses the sensitizing effect of EB. In rats with an LHRH concentration in the plasma of about 90 pg/ml, the sensitizing effect of estradiol is absent.     

Suppression by LH-releasing hormone (LHRH) of the augmenting effect of estradiol on the secretion of LH and FSH by the rat pituitary gland

Estradiol sensitizes the pituitary gland for the gonadotropin-releasing activity of LHRH. LHRH desensitizes the pituitary gland and does so in a dose-dependent manner. Moreover, LHRH dose-dependently suppresses the sensitizing effect of EB. In rats with an LHRH concentration in the plasma of about 90 pg/ml, the sensitizing effect of estradiol is absent.     

Cellular and subcellular localization of3H-diethylstilbestrol in the pituitary,oviduct and uterus of the female rat

Summary Female rats were injected with³H-diethylstilbestrol. The pituitaries, oviducts, and uteri were removed and processed for autoradiography. The nuclear uptake and retention in these tissues appeared similar to that seen after the injection of³H-estradiol except in the pars nervosa of the pituitary gland.This study was supported by US PHS Career Development Award No. NS00164 and PHS Grant No. NS21933.