K+-induced thyrotropin-releasing hormone release from superfused mediobasal hypothalami in rats. Inhibition by somatostatin.
Somatostatin (SRIF), in concentration of 10(-6) M, significantly inhibited the depolarization-induced release of immunoreactive thyrotropin-releasing hormone (IR-TRH) from superfused mediobasal hypothalami (MBH) containing mainly the median eminence (ME), without affecting the basal release of TRH. The total amount of K+-induced TRH release was 0.24 +/- 0.02 and 0.61 +/- 0.08 pg/MBH/min, respectively, in the presence and absence of SRIF in the medium. The data are consistent with a role of SRIF as a neuromodulator on TRH release from the ME. In contrast, superfusion with Locke medium containing triiodothyronine (10(-6) M) had no effect on basal and K+-induced IR-TRH release in our system.
D000818:Animals; D007033:Hypothalamus, Middle / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D011188:Potassium / Q000494:pharmacology*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000494:pharmacology*; D013973:Thyrotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014284:Triiodothyronine / Q000494:pharmacology
D014284:Triiodothyronine; D013004:Somatostatin; D013973:Thyrotropin-Releasing Hormone; D011188:Potassium