The effect of beta-endorphin on basal and TRH-stimulated TSH release in conscious male rats.
The inhibitory effect of beta-endorphin (EP) or other opioids on TSH secretion is, in contrast to their stimulating properties on PRL release, still a matter of debate. In the present study a dose of 1 microgram beta-EP injected intracerebroventricularly (IVT) in unstressed conscious male rats, though highly effective on PRL release, did not affect basal TSH levels, nor the TRH-induced TSH secretion. The previously reported inhibition of TSH release by opioids may therefore be an effect only seen when pharmacological doses are used.
Buydens
P
P
Department of Pharmacology, University of Brussels (VUB), Belgium.
Velkeniers
B
B
Golstein
J
J
Finné
E
E
Vanhaelst
L
L
D000818:Animals; D008297:Male; D011388:Prolactin / Q000097:blood; D051381:Rats; D013972:Thyrotropin / Q000097:blood / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000502:physiology*; D001615:beta-Endorphin / Q000502:physiology*
D013973:Thyrotropin-Releasing Hormone; D001615:beta-Endorphin; D011388:Prolactin; D013972:Thyrotropin