The Mechanism of Action of Mercuric Chloride on the Isolated Perfused Rat Kidney

Abstract

Abstract. Studies on 80 rat kidneys, perfused at constant flow, showed that mercuric chloride produced a marked increase in perfusion pressure within five minutes of administration. Adrenergic blocking agents (phentolamine and propranolol), angiotensin sensitivity depletion, bradykinin and low concentrations of mannitol had no effect on this increase in resistance. Perfusion of the kidney with 5 % mannitol solution, however, significantly reduced the increase of vascular resistance induced by mercuric chloride. Evidence is presented that mercuric chloride may evoke an increase in vascular resistance by inducing endothelial cell swelling, an action antagonised by the hypertonic effect of mannitol. Other possible contributory mechanisms are also discussed.

Nephrotoxic Mechanisms of Drugs and Environmental Toxins

“…The constricting vascular response of the renal vasculature and of aortic strips to increasing doses of HgCb is considerably reduced by alpha-adrenergic blockade with phentolamine and phenoxybenzamine. However, the marked increase in perfusion pressure obtained with HgCb in isolated, constant-flow perfused rat kidneys could not be altered by a large standard dose of phentolamine (Russell, 1975). Although not definitely conclusive, the latter study argues against the possibility that the mercury-induced vasoconstriction is adrenergically mediated.…”

Pro-inflammatory role of angiotensin II in mercuric chloride-induced nephropathy in rats

“…The role of Ang II in HgCl 2 -induced nephropathy has been reported and focused on the vasoconstrictive activity of this hormone (Russell, 1975;Yanagisawa et al, 1998). However, besides being a potent vasoactive peptide, Ang II has pro-inflammatory effects (Marchesi et al, 2008;Hayashi et al, 2010).…”

Comparison between Mannitol and Saline Infusion in HgCl₂-Induced Acute Renal Failure

“…A protective effect of acute mannitol administration has recently been demonstrated in the ischemic norepineph rine model of ARF [4,21]. Several reports indicate that mannitol is also effective in various nephrotoxic models of ARF in rats and dogs, but most of these studies were concerned with the maintenance phase of ARF and the mechanism of the protective action was not studied [14,18,20], In addition, experiments with mannitol in the HgCU model performed on the isolated dog and rat kidney were restricted to studies of the renal hemody namics and did not evaluate eventual changes in GFR [22,23].…”