Effect of vasopressin and cyclic AMP on permeability of isolated collecting tubules.

GRANTHAM, JARED J., AND MAURICE B. BURG. Effect ofuasopressin and cyclic AMP on permeability of isolated collecting tubules. Am. J. Physiol. 21 I (I) : 255-259. rg66.-The effect of vasopressin and cyclic 3’,5’-AMP on the permeability to water and urea of the isolated perfused rabbit collecting tubule was measured. When added to the solution bathing the outside of the tubule, these agents regularly increased both net water absorption along an osmotic gradient and the diffusional permeability to water as measured with THO in the absence of an osmotic gradient. When added only to the solution bathing the luminal border of the cells, vasopressin was ineffective. Urea permeability was not significantly altered by either vasopressin or cyclic 3’) $-AMP despite simultaneous increases in water permeability.