Thyrotropin-releasing hormone (TRH) modifies oxytocin release from the hypothalamo-neurohypophysial system in salt-loaded rats.
Rats drinking ad libitum tap water or hypertonic (i.e. 2%) sodium chloride solution were given intracerebroventricularly (i.c.v.), for three days, thyrotropin-releasing hormone (TRH) in a daily dose of 200 ng dissolved in 10 microliters of 0.9% sodium chloride. Treatment with TRH resulted in significantly decreased hypothalamic oxytocin content in both euhydrated (i.e. given tap water ad libitum) and salt-loaded rats. In rats drinking tap water, neurohypophysial oxytocin content decreased. Plasma oxytocin concentration was distinctly elevated under TRH treatment in rats euhydrated but, on the contrary, decreased in salt-loaded rats as compared with animals similarly drinking hypertonic saline but not TRH-treated. The present data suggest that TRH may be involved in some regulatory processes related to oxytocin biosynthesis and release from the rat hypothalamo-neurohypophysial system.
Ciosek
J
J
Department of Pathophysiology, University School of Medicine, Lódź, Poland.
Stempniak
B
B
D000818:Animals; D004326:Drinking; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D010121:Oxytocin / Q000096:biosynthesis / Q000097:blood / Q000378:metabolism*; D010904:Pituitary Gland, Posterior / Q000187:drug effects; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000494:pharmacology*; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D014667:Vasopressins / Q000378:metabolism
D014667:Vasopressins; D012965:Sodium Chloride; D010121:Oxytocin; D013973:Thyrotropin-Releasing Hormone