Changes in adenylate cyclase activity in rat pituitary after TRH and T3 injection in vivo.
Increased activity of adenylate cyclase in whole anterior pituitary was repeatedly found in groups of 3-6 adult male rats 5 min after iv injection of 10, 100 and 200 nmol of TRH kg-1. After the administration of 100 nmol TRH kg-1 the activity of adenylate cyclase was significantly increased at 2, 5, 10 and 30 min with a peak level at 5 min, while at 60 min the values did not differ from controls. The level of TSH in serum was significantly increased in all TRH injected groups with a peak value at 10 min, while no dose-response relationship was found at 5 min. Finally, the activity of adenylate cyclase was significantly decreased in animals injected with 20 nmol of L-triiodothyronine kg-1 180 min before sacrifice, the decrease being not overcome by 100 nmol TRH kg-1 injected 5 min before sacrifice.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008297:Male; D010903:Pituitary Gland, Anterior / Q000201:enzymology*; D051381:Rats; D013972:Thyrotropin / Q000097:blood; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D013997:Time Factors; D014284:Triiodothyronine / Q000494:pharmacology*
D014284:Triiodothyronine; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D000262:Adenylyl Cyclases