Expression of arginine vasopressin and vasopressin V-1a receptor mRNA in diabetic (db/db) mice

To assess the involvement of arginine vasopressin (AVP) in genetical diabet ic (db/db) mice, we examined. the mRNA expression levels of AVP and vasopre ssin V-1a receptors (V1aR) in brain and liver of db/db mice. In 10 week-old db/db mice, a significant elevation in blood sugar levels and plasma osmol ality were observed, showing obvious diabetic symptoms. There was a signifi cant increase in brain AVP mRNA levels in db/db mice. The expression level of liver V1aR mRNA in db/db mice was significantly down-regulated, presumab ly as a consequence of ligand-receptor interaction. This is in contrast to results that show no significant reduction in brain V1aR mRNA levels when c omparing db/db and control mice. Thus, it is possible that in the progress of genetic diabetes mellitus, AVP acts in liver than in brain through V1aR.