Metabolism: clinical and experimental
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Previous in vivo studies in cardiomyopathic hamsters suggested that the expression of vasopressin (AVP) V2 mRNA is up- regulated by angiotensin II. The present study was performed to determine whether angiotensin II plays a role in regulating the expression of AVP V2 mRNA and aquaporin-2 (AQP2) mRNA in the inner medullary collecting duct (IMCD) of the male Wistar rat. The expression of AVP V2 mRNA and AQP2 mRNA in the IMCD was measured by competitive reverse-transcriptase polymerase chain reaction (RT-PCR). ⋯ In the fifth and sixth groups of studies, we determined the direct effect of PKA and PKC on regulating the expression of V2 mRNA and AQP2 mRNA in the IMCD, respectively. Dibutryl cAMP stimulated an upregulation in the expression of V2 mRNA and AQP2 mRNA, whereas phorbol esters suppressed the expression of V2 mRNA. These results suggested that PKA stimulates and PKC suppresses the expression of V2 mRNA in the IMCD of the kidney.