Biomedical subjects

S G Chrysant

Publications and source records attributed to S G Chrysant.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Racial differences in pressure, volume and renin interrelationships in essential hypertension.

The interrelationships of arterial pressure, plasma volume (PV), and plasma renin activity were studied in 152 consecutive male patients with uncomplicated essential hypertension. Of these, 22 (17 white and 5 black) subjects had normal plasma volumes and because of the small number were not included in the analysis of results. The remaining 130 (35 black and 95 white) patients were classified as having either expanded or contracted plasma volume. A higher percentage of black (43%) than white (21%) subjects were volume expanded (PV > 19 ml/cm) and a lower percentage of blacks (57%) than whites (79%) were volume contracted (PV < 17 ml/cm). There was not significant difference in mean arterial pressure and plasma renin activity between the volume expanded and contracted black patients. In contrast, the white patients with contracted plasma volume had significantly higher arterial pressures (p < 0.05) and plasma renin activity (p < 0.001) than those with expanded plasma volume. More blacks than whites had low plasma renin activity and did not manifest the inverse relationship of plasma renin activity to plasma volume as did the whites. These data confirm and extend previous observations that the relationship between plasma volume and plasma renin activity (PRA) in the male patient with essential hypertension seems to differ between the black and white race. Efforts to explain the low PRA in black patients might be best directed toward those patients with suppressed PRA and with contracted intravascular volume.

Black People↗

PubMedDate not supplied

Captopril stimulation of differential renins in renovascular hypertension.

Twenty-six patients being evaluated for renovascular hypertension were studied to assess the diagnostic value of enhancing the differential between renal venous renins (PRA) by a single 25 mg oral dose of converting enzyme inhibitor (CEI, captopril). Antihypertensive medications were not discontinued prior to the study, and renal venous effluent was sampled before and 30 minutes after CEI. Eight patients without stenosis who did not have surgery had post-CEI ratios of less than 3.0. The other 18 patients had operative intervention, with 14 subsequently having improved blood pressure control. Of these 14, seven patients with unilateral stenosis, four patients with bilateral stenosis, and one patient without overt stenosis but with other evidence of reduced renal blood flow had 30-minute PRA ratios of 3.0 or greater. Five of these 14 patients had prestimulation ratios of less than 1.5 and might not be considered operative candidates by conventional criteria. Four other patients unimproved by surgery had post-CEI ratios of less than 3.0 despite a baseline ratio of greater than 1.5 in two of four. Only two patients with post-CEI ratios of less than 3.0 were improved with surgery. We conclude that a 30-minute post-CEI renal venous ratio of 3.0 or greater enhances the probability that patients with renovascular disease, and hypertension will respond to surgical intervention with improved blood pressure control.

Adolescent↗

PubMedDate not supplied

Effects of amiloride on arterial pressure and renal function.

Amiloride was administered to 13 male patients with mild essential hypertension and normal renal function. It effectively reduced supine and standing arterial pressures. The antihypertensive response was associated with a significant decrease in renal inulin clearance and a rise in plasma creatinine concentration, although both values at the end of seven weeks of therapy remained within normal limits. Serum potassium concentrations rose but did not reach hyperkalemic levels. Amiloride did not increase blood levels of glucose, uric acid, lipids, calcium, or urea nitrogen. We conclude that amiloride is an effective antihypertensive and antikaliuretic agents for patients with mild hypertension and normal renal function.

Adult↗

PubMedDate not supplied

The effects of salt and meclofenamate administration on the hypertension of spontaneously hypertensive rats.

The effects of prolonged (3 mos) high sodium intake and meclofenamate were studied in 2 groups of male SHR. Group 1 (6 rats) received 1% NaCl in tap water and Group 2 (8 rats) received 1% NaCl in tap water plus 50 microgram of meclofenamate per ml of drinking fluid. Renal metabolic and hemodynamic studies in the unanesthetized unrestrained state, showed that the meclofenamate treated rats had higher arterial pressures (p less than .005), left ventricular weight (p less than .05) and renal vascular resistance (p less than .005); lower glomerular filtration rate (p less than .005) than the control rats. The hematocrit and right ventricular weight were similar in the two groups of rats. This study has demonstrated that the combination of high sodium intake and meclofenamate have a greater damaging effect on the arterial pressure and renal function of SHR than salt alone.

Animals↗