The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Jack D. Barrett - One of the best experts on this subject based on the ideXlab platform.
-
Inactivation of Renin Substrate by soybean trypsin inhibitors : implications for measurement of circulating inactive Renin
Clinical and experimental hypertension (New York N.Y. : 1993), 1993Co-Authors: Jack D. Barrett, P. EggenaAbstract:Semipurified soybean trypsin inhibitor added to rat and human plasma leads to a concentration dependent decrease in the rate of angiotensin I generation. This inhibition is due to binding of Renin Substrate to the inhibitor. Renin Substrate present in nephrectomized rat plasma was more susceptible to binding than Substrate of the normal rat suggesting structural differences in the Substrate generated following nephrectomy. Because trypsin inhibition is necessary for measurement of active and inactive Renin, we examined several alternate trypsin inhibitors. The Bowman-Birk inhibitor from soybean had similar actions as purified soybean trypsin inhibitor while trypsin inhibitors from lima bean and chicken did not depress Renin Substrate, but did have variable effects on the measured levels of active and total plasma Renin. Surprisingly, crude soybean trypsin inhibitor did not suppress Renin Substrate and actually increased angiotensin I generation during PRA and PRC measurements. Since the crude preparation did not suppress Renin Substrate, changes in the specificity of the inhibitor may occur during its purification. The augmentation of PRA and PRC may be related to angiotensinase inhibitory actions.
-
Inactivation of Renin Substrate by Soybean Trypsin Inhibitors: Implications for Measurement of Circulating Inactive Renin
Clinical and Experimental Hypertension, 1993Co-Authors: Jack D. Barrett, Peter EggenaAbstract:Semipurified soybean trypsin inhibitor added to rat and human plasma leads to a concentration dependent decrease in the rate of angiotensin I generation. This inhibition is due to binding of Renin Substrate to the inhibitor. Renin Substrate present in nephrectomized rat plasma was more susceptible to binding than Substrate of the normal r at suggesting structural differences in the Substrate generated following nephrectomy. Because trypsin inhibition is necessary for measurement of active and inactive Renin, we examined several alternate trypsin inhibitors. The Bowman-Birk inhibitor from soybean had similar actions as purified soybean trypsin inhibitor while trypsin inhibitors from lima bean and chicken did not depress Renin Substrate, but did have variable effects on the measured levels of active and total plasma Renin. Surprisingly, crude soybean trypsin inhibitor did not suppress Renin Substrate and actually increased angiotensin I generation during.
David L. Mattson - One of the best experts on this subject based on the ideXlab platform.
-
Influence of elevated Renin Substrate on angiotensin II and arterial blood pressure in conscious mice.
Experimental physiology, 2005Co-Authors: Brian C. Cholewa, David L. MattsonAbstract:The present experiments were performed to determine the influence of intravenous administration of Renin Substrate on plasma angiotensin II levels and mean arterial blood pressure in conscious C57BL/6J mice. Mice with chronic indwelling femoral arterial and venous catheters were acutely or chronically administered intravenous doses of a synthetic peptide corresponding to the 14 amino acids on the N-terminal of angiotensinogen. A dose-dependent increase in arterial blood pressure was observed as the intravenous bolus dose of the Renin Substrate was increased from 0.18 to 180 nmol kg(-1) with a maximal increase in pressure of 40 +/- 3 mmHg achieved following administration of the 18 nmol kg(-1) bolus (n = 11). Additional experiments demonstrated that a sustained intravenous infusion of the Renin Substrate led to a long-term increase in arterial blood pressure. The continuous infusion of Renin Substrate at 0.05 nmol kg(-1) min(-1) for 3 days did not alter arterial blood pressure from the control level of 119 +/- 5 mmHg (n = 5); however, arterial blood pressure significantly increased to 129 +/- 6 mmHg with an infusion rate of 0.5 nmol kg(-1) min(-1) and further increased to 141 +/- 3 mmHg when the Renin Substrate infusion was increased to 5.0 nmol kg(-1) min(-1). Finally, the infusion of Renin Substrate at 5.0 nmol kg(-1) min(-1) resulted in a significant increase in plasma angiotensin II concentration from 34 +/- 6 pg ml(-1) in vehicle-infused mice to 288 +/- 109 pg ml(-1). These results demonstrate that modulation of the circulating level of angiotensinogen can alter the plasma angiotensin II level and arterial blood pressure in normal animals.
Peter Eggena - One of the best experts on this subject based on the ideXlab platform.
-
Inactivation of Renin Substrate by Soybean Trypsin Inhibitors: Implications for Measurement of Circulating Inactive Renin
Clinical and Experimental Hypertension, 1993Co-Authors: Jack D. Barrett, Peter EggenaAbstract:Semipurified soybean trypsin inhibitor added to rat and human plasma leads to a concentration dependent decrease in the rate of angiotensin I generation. This inhibition is due to binding of Renin Substrate to the inhibitor. Renin Substrate present in nephrectomized rat plasma was more susceptible to binding than Substrate of the normal r at suggesting structural differences in the Substrate generated following nephrectomy. Because trypsin inhibition is necessary for measurement of active and inactive Renin, we examined several alternate trypsin inhibitors. The Bowman-Birk inhibitor from soybean had similar actions as purified soybean trypsin inhibitor while trypsin inhibitors from lima bean and chicken did not depress Renin Substrate, but did have variable effects on the measured levels of active and total plasma Renin. Surprisingly, crude soybean trypsin inhibitor did not suppress Renin Substrate and actually increased angiotensin I generation during.
P. Eggena - One of the best experts on this subject based on the ideXlab platform.
-
Inactivation of Renin Substrate by soybean trypsin inhibitors : implications for measurement of circulating inactive Renin
Clinical and experimental hypertension (New York N.Y. : 1993), 1993Co-Authors: Jack D. Barrett, P. EggenaAbstract:Semipurified soybean trypsin inhibitor added to rat and human plasma leads to a concentration dependent decrease in the rate of angiotensin I generation. This inhibition is due to binding of Renin Substrate to the inhibitor. Renin Substrate present in nephrectomized rat plasma was more susceptible to binding than Substrate of the normal rat suggesting structural differences in the Substrate generated following nephrectomy. Because trypsin inhibition is necessary for measurement of active and inactive Renin, we examined several alternate trypsin inhibitors. The Bowman-Birk inhibitor from soybean had similar actions as purified soybean trypsin inhibitor while trypsin inhibitors from lima bean and chicken did not depress Renin Substrate, but did have variable effects on the measured levels of active and total plasma Renin. Surprisingly, crude soybean trypsin inhibitor did not suppress Renin Substrate and actually increased angiotensin I generation during PRA and PRC measurements. Since the crude preparation did not suppress Renin Substrate, changes in the specificity of the inhibitor may occur during its purification. The augmentation of PRA and PRC may be related to angiotensinase inhibitory actions.
Brian C. Cholewa - One of the best experts on this subject based on the ideXlab platform.
-
Influence of elevated Renin Substrate on angiotensin II and arterial blood pressure in conscious mice.
Experimental physiology, 2005Co-Authors: Brian C. Cholewa, David L. MattsonAbstract:The present experiments were performed to determine the influence of intravenous administration of Renin Substrate on plasma angiotensin II levels and mean arterial blood pressure in conscious C57BL/6J mice. Mice with chronic indwelling femoral arterial and venous catheters were acutely or chronically administered intravenous doses of a synthetic peptide corresponding to the 14 amino acids on the N-terminal of angiotensinogen. A dose-dependent increase in arterial blood pressure was observed as the intravenous bolus dose of the Renin Substrate was increased from 0.18 to 180 nmol kg(-1) with a maximal increase in pressure of 40 +/- 3 mmHg achieved following administration of the 18 nmol kg(-1) bolus (n = 11). Additional experiments demonstrated that a sustained intravenous infusion of the Renin Substrate led to a long-term increase in arterial blood pressure. The continuous infusion of Renin Substrate at 0.05 nmol kg(-1) min(-1) for 3 days did not alter arterial blood pressure from the control level of 119 +/- 5 mmHg (n = 5); however, arterial blood pressure significantly increased to 129 +/- 6 mmHg with an infusion rate of 0.5 nmol kg(-1) min(-1) and further increased to 141 +/- 3 mmHg when the Renin Substrate infusion was increased to 5.0 nmol kg(-1) min(-1). Finally, the infusion of Renin Substrate at 5.0 nmol kg(-1) min(-1) resulted in a significant increase in plasma angiotensin II concentration from 34 +/- 6 pg ml(-1) in vehicle-infused mice to 288 +/- 109 pg ml(-1). These results demonstrate that modulation of the circulating level of angiotensinogen can alter the plasma angiotensin II level and arterial blood pressure in normal animals.