Thyrotropin-releasing hormone does not alter the release of melanocyte-stimulating hormone or adrenocorticotropic hormone from the rat pars intermedia.

Thyrotropin-releasing hormone (TRH) has been reported to stimulate the release of melanocyte-stimulating hormone (MSH) from the pars intermedia (PI) of Rana esculenta. To test its effect on the rat PI, acutely dispersed rat PI cells, as well as whole nervosa-intermedias (NI), were incubated with synthetic TRH, from 10(--10)--10(--4)M. TRH did not alter the release of either MSH or adrenocorticotropic hormone (ACTH).