[Main factors determining the functional state of pregnant rat's uterus]

In a review article the authors based on the analysis of the literature, conclude that the Calcitonin Gene-Related Peptide (CGRP) inhibits myometrial contractility at the background of the nonselective Nitric Oxide Synthase inhibitor (L-NAME) action. Along with this, there are evidences that in NOS-deficient rats the process of pregnancy proceeds normally. Thus, literature data indicate that CGRP, independently of Nitric Oxide is included in the myometrium relaxing system, which of course does not exclude its joint action with both Nitric Oxide and other relaxing factors. Moreover, according to our data L-Arginine, causes complete inhibition of spontaneous contractile activity of the rats' myometrial strips, but the administration of L-NAME, eliminates the inhibitory effect - contractile activity was restored.