Steroids gonadal

Testiculat androgens are synthesized in the interstitial tissue by the Leydig cells. The immediate precursor of the gonadal steroids, as for the adrenal steroids, is cholesterol. The rate-limiting step, as in the adrenal, is delivery of cholesterol to the inner membrane of the mitochondria by the transport protein StAR. Once in the proper location, cholesterol is acted upon by the side chain cleavage enzyme P450scc. The conversion of cholesterol to pregnenolone is identical in adrenal, ovary, and testis. In the latter two tissues, however, the reaction is promoted by LH rather than ACTH. 

Gonadal Steroids Are Transported by Sex Hormone-Binding Globulin... 

Dantzer R. (1998). Vasopressin, gonadal steroids and social recognition. Prog Brain Res 119, 409-441. 

Ovarian hormones influence fluid intake by interaction with the brain renin-angiotensin system and it has been shown that gonadal steroids affect brain fluid-electrolyte balance by interactions with vasopressin. Both hyperos-molarity and increased intracranial pressure stimulate vasopressin release and intraperitoneal administration of vasopressin antagonists decrease brain volume. 

Both aromatization and 5a-reductase are regulated by gonadal steroids. In mammals such as the rat, it is principally the neural aromatase activity that is upregulated by androgens acting via neural androgen receptors [1],... 

McEwen, B. S. Gonadal steroid influences on brain development and sexual differentiation. In Reproductive Physiology IV. Ed Greep, R. University Park University Park Press, 1983, pp99-145. 

Matsumoto, A., Arai, Y., Urano, A. and Hyodo, S. Molecular basis of neuronal plasticity to gonadal steroids. Functional Neurol 10 59-76,1995. 

Somjen D, Kohen F, Jaffe A, Amir-Zaltsman Y, Knoll E, Stern N (1998) Effects of gonadal steroids and their antagonists on DNA synthesis in human vascular cells. Hypertension 32 39-45... 

Gonadal Steroid Hormones Modulate Vaginal Marking 22.3.1 Systemic Gonadal Steroid Hormones... 

Gonadal Steroid Hormones in the Central Nervous System... 

Behavioral endocrinologists have focused their attention on sexual, parental and aggressive behaviors, describing various relationships between the gonadal steroids and these behaviors. Most research in this area has been done in laboratory rodents, and especially in domestic rats. 

Miller MM, Silver J, et al (1984) Effects of gonadal steroids on the in vivo binding of [ l]alpha-bungarotoxin to the suprachiasmatic nucleus. Brain Res 290(l) 67-75 Mochizuki T, Villemagne VL, et al (1998) Nicotine induced up-regulation of nicotinic receptors in CD-I mice demonstrated with an in vivo radiotracer gender differences. Synapse 30(1) 116-118... 

Endocrine effects Statins interfere with cholesterol synthesis and lower circulating cholesterol levels and, as such, might theoretically blunt adrenal or gonadal steroid hormone production. Small declines in total testosterone with no commensurate elevation in LH have been noted with the use of fluvastatin. Pravastatin showed inconsistent results with regard to possible effects on basal steroid hormone levels atorvastatin, lovastatin, rosuvastatin, and simvastatin did not reduce basal plasma cortisol concentration or basal plasma testosterone concentration or impair adrenal reserve. Appropriately evaluate patients who display clinical evidence of endocrine dysfunction. Exercise caution when administering HMG-CoA reductase inhibitors with drugs that affect steroid levels or activity, such as ketoconazole, spironolactone, and cimetidine. 

In addition to GnRH, several other effector molecules modulate secretion of gonadotrophins. These include not only inhibins and activins, but also gonadal steroids. All of these combine via complex feedback loops to modulate gonadotrophin production and, hence, reproductive function (Figure 8.15). 

THE IMPACT OF GONADAL STEROIDS AND DEVELOPMENT OF SEXUALLY DIMORPHIC AREAS... 

Arnold, A.P., and Gorski, R.A. (1984) Gonadal steroid induction of structural sex differences in in the central nervous system. Ann Rev Neurosci 7 413 42. 

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