Vascular structural changes in DOC-salt hypertensive rats.

Vascular alterations in DOC-salt hypertensive rats 10 and 30 days after the onset of the treatment were studied and compared with those from rats receiving only DOC, rats drinking salt, and control rats. Wet weight and absolute amounts of deoxyribonucleic acid (DNA) and ribonucleic acid (RnA) of the artery wall were significantly increased in DOC-salt rats 10 and 30 days after the onset of the treatment. RNA/DNA and protein/DNA ratios were similar in all the experimental groups. The arteries of DOC-salt animals incorporated tritiated thymidine at a higher rate 10 days after beginning the treatment, while the uptake was similar in all the animals at the end of the experimental period. These results would indicate that, in this type of hypertension, the increase in artery mass is mainly the result of cellular hyperplasia, which is active during the early phase of the process; afterward the vascular wall reaches a new steady state characterized by a greater number of cells and no further cell proliferation.