TY - JOUR
T1 - Effects of Nifedipine on the Renal Vascular Responses and Blood Pressure Responses to Norepinephrine and Angiotensin II in the Anesthetized Rabbit
AU - Ito, Sadayoshi
AU - Seino, Masahide
AU - Yasujima, Minoru
AU - Abe, Keishi
AU - Yoshinaga, Kaoru
PY - 1983/1
Y1 - 1983/1
N2 - Ito, S., Seino, M., Yasujima, M., Abe, K. and Yoshinaga, K. Effects of Nifedipine on the Renal Vascular Responses and Blood Pressure Responses to Norepinephrine and Angiotensin II in the Anesthetized Rabbit. Tohoku J. exp. Med., 1983, 140 (1), 53-58-Effects of a Ca-antagonist, nifedipine, on renal vascular responses and systemic pressor responses to angiotensin II and norepinephrine were studied in anesthetized rabbits. The changes of renal blood flow were estimated by an electromagnetic flowmeter. After the intravenous administration of nifedipine (50μg/kg), mean blood pressure decreased from 116±3.1 mmHg to 102±3.4 mmHg (p<0.001). Renal vascular responses to angiotensin II were attenuated significantly after the administration of nifedipine, but not changed to norepinephrine. Pressor responses to angiotensin II at a low dose were significantly diminished after the administration of nifedipine (p<0.05), whereas it had no effect at higher doses. Nifedipine tended to suppress the increase in arterial pressure induced by norepinephrine, but the changes were not statistically significant. These results suggest that calcium influx in the vascular smooth muscle cells is not likely to be a common pathway in the vasoconstrictor reaction to angiotensin II and norepinephrine in anesthetized rabbit. -nifedipine; norepinephrine; angiotensin II; blood pressure; renal vascular response.
AB - Ito, S., Seino, M., Yasujima, M., Abe, K. and Yoshinaga, K. Effects of Nifedipine on the Renal Vascular Responses and Blood Pressure Responses to Norepinephrine and Angiotensin II in the Anesthetized Rabbit. Tohoku J. exp. Med., 1983, 140 (1), 53-58-Effects of a Ca-antagonist, nifedipine, on renal vascular responses and systemic pressor responses to angiotensin II and norepinephrine were studied in anesthetized rabbits. The changes of renal blood flow were estimated by an electromagnetic flowmeter. After the intravenous administration of nifedipine (50μg/kg), mean blood pressure decreased from 116±3.1 mmHg to 102±3.4 mmHg (p<0.001). Renal vascular responses to angiotensin II were attenuated significantly after the administration of nifedipine, but not changed to norepinephrine. Pressor responses to angiotensin II at a low dose were significantly diminished after the administration of nifedipine (p<0.05), whereas it had no effect at higher doses. Nifedipine tended to suppress the increase in arterial pressure induced by norepinephrine, but the changes were not statistically significant. These results suggest that calcium influx in the vascular smooth muscle cells is not likely to be a common pathway in the vasoconstrictor reaction to angiotensin II and norepinephrine in anesthetized rabbit. -nifedipine; norepinephrine; angiotensin II; blood pressure; renal vascular response.
UR - http://www.scopus.com/inward/record.url?scp=0020616518&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0020616518&partnerID=8YFLogxK
U2 - 10.1620/tjem.140.53
DO - 10.1620/tjem.140.53
M3 - Article
C2 - 6868080
AN - SCOPUS:0020616518
VL - 140
SP - 53
EP - 58
JO - Tohoku Journal of Experimental Medicine
JF - Tohoku Journal of Experimental Medicine
SN - 0040-8727
IS - 1
ER -