[Effect of the calcitonine gene-related peptide on the myometrium contractile activity].

It is known that in the processes of contraction, as well as of relaxation of the myometrium, besides widely accepted regulatory mechanisms, such as steroid hormones, also participate catecholamine, oxytocine and prostaglandine, and other substances of peptide nature. In particular one of such compounds was studied in the present investigation. This compound is known as the peptide connected to the calcitonine gene (CGRP), whose role in the contractile activity of the myometrium is very significant. Our results certify that for the execution of the relaxing effect of the CGRP on the rat's myometrium, the nitric oxide is not an essential factor. The data obtained by us on the background of an action of the non-selective inhibitor of the nitric oxide synthase (NOS)--nitro-L-arginine-methyl-ester (L-NAME)--practically does not differ from the data obtained in the absence of the latter, in different periods of gestation. This must evidence that inhibitory influence of the CGRP on the myometrium stripe, is either completely independent of the nitric oxide, or its role in performing this action is absolutely insignificant.