Compared myocardial and vascular effects of captopril and dihydralazine during hypertension development in spontaneously hypertensive rats.
When administered to young spontaneously hypertensive rats (SHRs), dihydralazine (25 mg kg-1, daily) and captopril (100 mg kg-1, daily) prevent with the same efficacy genetic hypertension development (GHD). Dihydralazine treatment increased vascular mesenteric compliance, as shown by a significant decrease in the stiffness of the vessels (-27%), and induced slight reductions in contractility (-12%) and in wall to lumen (W/L) ratio (-15%). After treatment withdrawal, all these parameters returned to control values within 7 weeks, as did blood pressure. Captopril treatment also strongly increased the mesenteric vessels compliance, vessel stiffness being decreased by 16%, and reduced their contractility (-15%) and their W/L ratio (-30%). These effects as well as those exerted on blood pressure persisted up to 7 weeks after treatment ceased although there was a slight trend to a progressive reduction in the intensity of both phenomena. These experiments show that captopril but not dihydralazine has a long-lasting effect in opposing the functional and morphological vascular alterations occurring during GHD in SHRs and this phenomenon probably contributes to a large extent to the sustained preventive effects of the drug against GHD.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects*; D002216:Captopril / Q000494:pharmacology*; D004078:Dihydralazine / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006830:Hydralazine / Q000031:analogs & derivatives*; D006973:Hypertension / Q000503:physiopathology* / Q000517:prevention & control; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011392:Proline / Q000031:analogs & derivatives*; D051381:Rats; D011919:Rats, Inbred Strains
D006830:Hydralazine; D011392:Proline; D002216:Captopril; D004078:Dihydralazine