AJP - Renal Physiology, Vol 249, Issue 5 739-F744, Copyright © 1985 by American Physiological Society
Vascular and renal effects of leukotriene C4 in conscious rats
J. Filep, B. Rigter and J. C. Frolich
To investigate the possible renal effects of leukotriene C4 (LTC4) renal
function was monitored in conscious unrestrained rats. Intravenous
injections of 2, 4, and 8 micrograms/kg LTC4 markedly and dose-dependently
elevated urine flow (by 64, 91, and 133%, respectively) with a concomitant
increase in urinary sodium (61, 81, and 118%) and potassium (39, 50, and
76%) excretion. All changes were statistically significant. There was a
tendency for glomerular filtration rate to increase, but this change
reached statistical significance only after the highest dose of LTC4.
Moreover, 8 micrograms/kg LTC4 reduced p-aminohippurate clearance by 33%. A
dose-dependent increase in mean arterial pressure (15 mmHg at 2
micrograms/kg, 20 mmHg at 4 micrograms/kg, and 30 mmHg at 8 micrograms/kg)
was observed following LTC4 administration. While the administration of FPL
55712, a putative antagonist of leukotrienes, had no effect on mean
arterial pressure and kidney function, it significantly attenuated the
vasopressor effect of LTC4 and practically completely abolished
LTC4-induced changes in both renal hemodynamics and water and electrolyte
excretion. These results raise the possibility that leukotrienes might be
involved in the regulation of renal hemodynamics and could modify urinary
electrolyte excretion under conditions in which leukotriene formation is
enhanced.
