Structural change in the rat hindlimb during deoxycorticosterone acetate hypertension; its reversibility and prevention.

This study measured the time course of the development and reversal of structural change in resistance vessels during deoxycorticosterone acetate (DOCA) hypertension and after cessation of DOCA in Wistar rats by hindquarter perfusion. The relationship of structural change to blood pressure was further assessed by preventing hypertension during DOCA treatment with hydralazine. Blood pressure rose progressively during DOCA treatment reaching 198.6 +/- 2.0 (s.e.) mmHg at 10 weeks. Five weeks after the cessation of DOCA, when it had been given for 2 weeks, hypertension reversed completely but after 4, 8 and 10 weeks of treatment, post-DOCA reversal of hypertension was only partial. Hindquarter perfusion pressure at maximum vasodilatation and maximum vasoconstriction increased with increasing duration of DOCA treatment and reversed 5 weeks post-DOCA to a similar degree to the blood pressure with only partial reversal of both perfusion pressures and hypertension when DOCA had been given for 8 and 10 weeks. Hydralazine did not completely prevent heart hypertrophy in the DOCA rats and caused some cardiac hypertrophy in the control ('vehicle' only) rats, although it both prevented hypertension and evidence of vascular structural change in DOCA rats.