PRIMING EFFECT OF LUTEINIZING HORMONE RELEASING FACTOR: IN-VITRO STUDIES WITH RAISED POTASSIUM ION CONCENTRATIONS

Abstract

The priming effect of LH-RF [luteinizing hormone-releasing factor] on rat pituitary gonadotrophs probably does not depend upon a qualitative or quantitative alteration in the receptor mechanism for LH-RF. Since the amount of LH released by K+ during a first hour of incubation is similar to that released by LH-RF, and the sequence K+-LH-RF does not elicit the priming effect, the effect cannot simply be a consequence of LH release. The priming effect may be due to the provision of more LH in a readily releasable form. This could depend upon the synthesis of new LH or a shift of LH from a storage pool. The possibility cannot be excluded that the priming effect is due to facilitation of the cellular LH-release mechanism consequent upon exposure to LH-RF.