EFFECT OF HISTAMINE AND ANTIHISTAMINES ON RENAL HEMODYNAMICS AND FUNCTIONS IN ISOLATED PERFUSED CANINE KIDNEY

  • 1 January 1976
    • journal article
    • research article
    • Vol. 198  (3) , 661-667
Abstract
Histamine was infused intra-arterially (10-40 .mu.g/min) into isolated blood perfused canine kidneys while functional and hemodynamic parameters were monitored. When perfusion pressure (PP) was kept constant during the infusion of histamine, renal blood flow (RBF) increased from 137 .+-. 9 to 181 .+-. 9 ml/min (P < .001). A greater increase in RBF occurred to the inner renal cortex than the outer renal cortex as measured by radioactive microspheres. The fractional outer/inner cortical blood flow changed from 79:21 before histamine to 74:26 during its infusion (P < .001). Histamine did not alter creatinine clearance (CCr), urine volume (V), Na excretion (UNaV) or the fractional excretion of Na (FENa) or water (FEH2o) under these conditions. When renal blood flow was held constant during the infusion of histamine, PP decreased from 126/106 .+-. 2 to 100/81 .+-. 2 mm Hg (P < .001). This was accompanied by significant reductions in the clearance of creatinine and salt and water excretion, and an increased tubular reabsorption of Na and water. In this situation absolute blood flow decreased to the outer renal zone (108 .+-. 4 to 100 .+-. 4 ml/min) but increased to the inner renal zone (28 .+-. 3 to 36 .+-. 3 ml/min) resulting in a significant redistribution of fractional blood flow. The outer/inner percentage of RBF measured 77:23 before histamine and 72:28 after histamine. In contrast to the effects of histamine at constant PP, CCr, V, UNa V, FENa and (FEH2o) were decreased when histamine infusion reduced the PP. Administration of the H1 receptor antagonist, diphenhydramine, blocked the hemodynamic effects of histamine; the administration of an H2 receptor antagonist, metiamide, did not alter the histamine response. Similar vasodilatory responses to histamine were observed in isolated blood perfused dog and cat kidneys. Vasoconstrictor responses to histamine occurred in isolated dog and cat kidneys perfused with Krebs'' solution and in isolated rabbit kidneys whether perfused with blood or Krebs'' solution.