Forearm vascular responses in normotensives and hypertensives after sublingual nifedipine.
Some hemodynamic variables of ten untreated hypertensives and nine normotensives were compared before and at 10, 30, and 60 min after nifedipine 10 mg sublingually. Serum nifedipine concentration was measured at each of these times, and was similar between groups. Resting forearm venous compliance did not differ between groups, and did not change after nifedipine. Nifedipine did not change mean arterial pressure significantly, but heart rate was increased in both groups. Resting forearm blood flow was significantly higher in hypertensives than normotensives and forearm vascular resistance was correspondingly lower. Forearm blood flow increased and vascular resistance fell after nifedipine in normotensives, but did not change significantly in hypertensives. Our data do not suggest any effect of nifedipine on peripheral venous compliance. We do not confirm the reported decrease in forearm venous compliance in hypertensives, but the characteristics of blood flow, vascular resistance, and lack of effect of nifedipine on blood pressure likely reflect a predominance of early hypertensives in our study population.
D000284:Administration, Oral; D000328:Adult; D001775:Blood Circulation / Q000187:drug effects*; D002214:Capsules; D005542:Forearm; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D014655:Vascular Resistance / Q000187:drug effects*
D002214:Capsules; D009543:Nifedipine