Effect of Metapyrone on LH and FSH Responses to GnRH

Abstract

Contemporary endocrinology has doubtlessly established the existence of a negative feedback loop system between the Leydig and the pituitary cells. However, the physiology of this endocrine circuit cannot adequately explain the blood testosterone fall observed during a surgical stress (CluJrters, Odelt and Thompson 1968); it was indeed reported that neither blood ICSH, FSH and TSH levels did vary significantly during such stressful situations.Recently, we reported a significant (p < .005) blood testosterone increase in 23 healthy varsity students undergoing a 30-Requests for reprints should be addressed to: Or.Oisturbances of gonadal function are common in adrenal disorders. Intake of large amounts of glucocorticoids or Cushing's syndrome are associated with menstrual disorders. Amenorrhea and irnpaired fertility are sequelae of untreated adrcnogenital syndrome. Glucocorticoid administration depressed and metyrapone enhanced LH response to LHRH in men and women (Sakakura, Takebe and Nakagawa 1975). We re port here the LH and FSH responses to GnRH in heaIthy men hcforc and after metyrapone.

Suppression of Luteinizing Hormone Induced by Adrenocorticotrophin in Healthy Women

“…Glucocorticoids lower the basal secretion of luteinizing hormone (LH) and folliclestimulating hormone (FSH) and blunt the gonadotrophin response to luteinizing hormone releasing hormone (LH-RH; Sakakura, Takebe & Nakagawa, 1975;Sowers & Fayez, 1979;Sowers, Rice & Blanchard, 1979), whereas the response to LH-RH in men and women is enhanced by pretreatment with metyrapone (Sakakura et al 1975;Muraleedharan, Sialy & Rastogi, 1977). While these observations suggest interactions of glucocorticoids with gonadotrophin secretion, unchanged plasma levels of LH and FSH have been reported in healthy men after the administration of adrenocorticotrophin (ACTH) in spite of a stimulation of endogenous production of cortisol (Beitins, Bayard, Kowarski & Migeon, 1973;Irvine, Toft, Wilson, Fraser, Wilson, Young, Hunter, Ismail & Burger, 1974;Schaison, Durand & Mowszowicz 1978).…”

Alterations of Plasma Levels of Pituitary Hormones after Oral Application of Metyrapone

“…Particularly, the findings about influences on the somatotrophic system are rather controversial (Kunita, Takebe, Nakagawa, Sawano and Horiuchi 1970;Sawin, Spark and Mitchell 1971;Bruno, Leclerq, Virasor and Copinski 1971; Takahara, Ogawa and Ofuji 1972; Sawano, Saito, Shizume and Takebe 1972;Bacon, Larson, Spencer and Kelch 1975). Similarly contradictory, scanty or non-existent is the information about alterations of the gonadotrophic (Sakakura, Takebe and Nakagawa 1975;Muraleedharan, Sialy and Rastogi 1977; Sakakura, Yoshioka and Takebe 1978), the thyrotrophic (Re, Kourides, Ridgway, Weintraub and Maloof 1976), and lactotrophic function of the pituitary. We report here on the short-time kinetic profiles of plasma ACTH, STH, LH, FSH, prolactin and TSH after oral application of M. § 100 | 50 u < 10 a. I 5 3.5 3.0 -2.5 | 2.0 -1.5 £ i.o 0.5 J i M \H -^ •-.…”