Central effects of long-term relaxin expression in the rat

A recombinant adenovirus containing the human H2 preprorelaxin (hH2) cDNA and a reporter gene was coinjected with a transactivator virus (Ad-tTA) into the lateral cerebral ventricles of female rats. Cardiovascular effects were measured over a 21-day period. Circulating vasopressin in the periphery was significantly greater (P < .0001) in the relaxin-treated group throughout the experimental period, compared with controls. There was a significant decrease in plasma osmolality (P < .05) by approximately 10 mmol/L in the treated group by day 14. Immunofluorescence for hH2 present in cryosections showed rAd transduction and hH2 expression from ependymal cells of the ventricular system. Adenovirus-mediated delivery of hH2 to the brain is capable of producing bioactive relaxin that affects cardiovascular parameters.