Onset and offset of structural arteriolar changes in DOCA/salt hypertension in the rat.

1. Structural changes in resistance vessels were studied sequentially (a) by hindquarter perfusion and (b) by planimetry of renal arterioles less than or equal to 20 micrometers radius, for 10 weeks during development of DOCA (deoxycorticosterone acetate)/salt hypertension in uninephrectomized rats and 5 weeks after cessation of DOCA treatment. 2. Blood pressure and haemodynamically significant structural change increased progressively during DOCA treatment and both had partially reversed 5 weeks after cessation of DOCA. 3. Arteriolar structural changes contribute progressively to the hypertension during 10 weeks DOCA treatment. Partial reversal of structural changes contributes to the fall in blood pressure after cessation of DOCA. The persisting postDOCA hypertension can be attributed to relatively irreversible structural changes.