TY - JOUR
T1 - Relationship between baroreflex sensitivity, renin suppression and natriuresis in salt-sensitive rabbits
AU - Weinstock, Marta
AU - Borosh, Michal
AU - Kafri, Orna
AU - Kaczmarczyk, Gabriele
PY - 1991/9
Y1 - 1991/9
N2 - This study determined the influence of baroreflex sensitivity (BRS) on the rate of urinary sodium excretion and plasma renin activity (PRA) in response to a saline infusion in conscious male rabbits specifically bred for high (Croup I; n = 7) and low (Group II; n = 10) BRS and in seven control animals. Only Group II showed significant increases in blood pressure on a chronic high-salt intake. After ensuring that each animal was in sodium balance, a (0.7-0.9%) saline infusion of 3-4 ml/kg per h for 90 min (25% daily sodium intake for each rabbit) was given and urine collected at 15-min intervals via a bladder catheter. No differences were found in control urine volumes, urinary sodium or PRA. Group I excreted over 50% of the sodium load and Group II less than 20% within 90 min. PRA fell by more than 30% within 30 min in six Group I rabbits but decreased by less than 30% or increased in Group II. In the control animals, sodium excretion rates and PRA suppression were also much greater in those with high BRS. A highly significant correlation (r = 0.808, P < 0.01) was found between the per cent of the sodium load excreted and BRS. It is suggested that the delayed sodium excretion and blood pressure elevation in salt-sensitive subjects may be due to a genetic impairment in baroreflex control of rena.
AB - This study determined the influence of baroreflex sensitivity (BRS) on the rate of urinary sodium excretion and plasma renin activity (PRA) in response to a saline infusion in conscious male rabbits specifically bred for high (Croup I; n = 7) and low (Group II; n = 10) BRS and in seven control animals. Only Group II showed significant increases in blood pressure on a chronic high-salt intake. After ensuring that each animal was in sodium balance, a (0.7-0.9%) saline infusion of 3-4 ml/kg per h for 90 min (25% daily sodium intake for each rabbit) was given and urine collected at 15-min intervals via a bladder catheter. No differences were found in control urine volumes, urinary sodium or PRA. Group I excreted over 50% of the sodium load and Group II less than 20% within 90 min. PRA fell by more than 30% within 30 min in six Group I rabbits but decreased by less than 30% or increased in Group II. In the control animals, sodium excretion rates and PRA suppression were also much greater in those with high BRS. A highly significant correlation (r = 0.808, P < 0.01) was found between the per cent of the sodium load excreted and BRS. It is suggested that the delayed sodium excretion and blood pressure elevation in salt-sensitive subjects may be due to a genetic impairment in baroreflex control of rena.
KW - Conscious rabbits
KW - Genetic differences in cardiac baroreflex sensitivity
KW - Intravenous saline
KW - Plasma renin activity
UR - http://www.scopus.com/inward/record.url?scp=0025733937&partnerID=8YFLogxK
U2 - 10.1097/00004872-199109000-00005
DO - 10.1097/00004872-199109000-00005
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C2 - 1663980
AN - SCOPUS:0025733937
SN - 0263-6352
VL - 9
SP - 799
EP - 804
JO - Journal of Hypertension
JF - Journal of Hypertension
IS - 9
ER -