Effect of chronic hypertension and antihypertensive therapy on endothelial cell replication in the spontaneously hypertensive rat.
In the present study we examined endothelial cell replication in animals with spontaneous hypertension and their normotensive controls. We were unable to demonstrate a difference between replication rates of spontaneously hypertensive rats as compared with Wistar Kyoto rats. Studies of endothelial replication rates and blood pressure in normal rats revealed no correlation between the two. In contrast, treatment with antihypertensive drugs produced variable results: lowering blood pressure in all experiments, but only lowering replication rates to a significant level in some spontaneously hypertensive rats. This effect, moreover, was not proportional to the effect of the drug regimen on blood pressure. Perhaps most surprising was the effect of withdrawal of therapy. Once therapy was discontinued in the spontaneously hypertensive rats, both pressure and replication rose. The increase in replication was also seen in the Wistar Kyoto strain, suggesting that the antihypertensive drugs have some as yet unclear effect on the endothelium itself.
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight; D002455:Cell Division; D004727:Endothelium / Q000187:drug effects / Q000473:pathology; D005260:Female; D006321:Heart / Q000187:drug effects*; D006973:Hypertension / Q000473:pathology*; D008297:Male; D008938:Mitosis / Q000187:drug effects*; D008940:Mitotic Index / Q000187:drug effects*; D009929:Organ Size; D051381:Rats; D011919:Rats, Inbred Strains
D000959:Antihypertensive Agents