[Effect of vasopressin on water permeability of epithelial cells in the kidney collecting duct during postnatal ontogenesis in rats].

Desmopressin caused a statistically significant increase in the water permeability of the outer medullary collecting ducts (OMCD) in 22-days old rats. Concentration of specific V2 receptors increased during postnatal period. Comparison of the V2 receptors concentration, mRNA contents, and changes of water permeability in response to desmopressin suggests that parts of transduction mechanism is situated deeper than the receptors, determines the physiological mechanism at the end of weaning period.