Plasma endothelin and renal function during infrarenal aortic crossclamping and nifedipine infusion

Nifedipine Can Preserve Renal Function in Patients Undergoing Aortic Surgery with Infrarenal Crossclamping

“…While a direct intrarenal action of N cannot be ruled out, we suggest that the more pronounced reduction of the afterload combined with the maintenance of an adequate cardiac output could be the main pathophysiological mechanism responsible for the reduction of intrarenal resistances and stability of postop erative GFR in patients of group A. However, we have previously shown that ICC promotes an increase in plas ma ET [10] and anoxia and surgical manipulations have been reported to enhance endothelial synthesis of ET [21,22] which has been demonstrated to decrease RBF and GFR [23]. These similarities suggest that ET may play a role in the intra-and postoperative reduction of GFR.…”

“…UK) as previously reported [10], In brief, 10 ml o f blood was collected while the subjects were recumbent al 9 a.m. after an overnight fast, in a syringe containing EDTA and aprotinine, immediately centrifuged at 4°C in order to remove cells and the plasma was stored below 20 °C until assay. After equilibration o f the column with methanol and water.…”

“…This complication occurs in 2-7% of pa tients undergoing ICC for aneurysm or Leriche disease, although milder forms of renal failure with preserved diuresis are frequent [3][4][5][6][7], To prevent renal vasoconstriction pre-and intraopera tive extracellular volume expansion as well as mannitol and low dose of dopamine infusion have been attempted with conflicting results [8,9], In contrast, we have pre viously observed that nifedipine infusion prevented any reduction in glomerular filtration rate during ICC [10] and these findings lead us to undertake the present study. The goals of this study were several: (1) to confirm the efficacy of nifedipine in a larger number of patients undergoing ICC; (2) to compare the effect of a calcium entry blocker to that of low-dose dopamine, and (3) to obtain more information about the possible mechanism of nifedipine action.…”

“…The goals of this study were several: (1) to confirm the efficacy of nifedipine in a larger number of patients undergoing ICC; (2) to compare the effect of a calcium entry blocker to that of low-dose dopamine, and (3) to obtain more information about the possible mechanism of nifedipine action. With respect to the mechanisms responsible, we concentrated on endothelin (ET) [10], renin and thromboxane IT (TxIT) [11] as these have been advanced as possible modulators of the renal vasocon striction observed after ICC. While calcium entry block ers have no effect on renin secretion [12], little informa tion is available regarding their effect on prostanoids syn thesis and endothelin production.…”

Preoperative inhibition of angiotensin-converting enzyme improves systemic and renal haemodynamic changes during aortic abdominal surgery

“…Powerful endogenous vasoconstricting substances such as thromboxane A2, oxygen-derived free radicals and endothelin-1 have been shown to be released during aortic clamping, and all might contribute to prolonged impairment of renal function [5][6][7]. The importance of the renin-angiotensin system (RAS) has also been emphasized in the regulation of arterial pressure, blood flow distribution and renal function [8].…”