AJP - Regulatory, Integrative and Comparative Physiology, Vol 253, Issue 2 375-R378, Copyright © 1987 by American Physiological Society
Diuretic and natriuretic properties of prestegane B, a mammalian lignan
G. E. Plante, C. Prevost, A. Chainey, P. Braquet and P. Sirois
The effect of increasing doses of prestegane B, a synthetic lignan, was
examined in the anesthetized normal rat, using clearance methodology.
Increasing doses of prestegane B 0.5, 1.0, 2.0, and 5.0 mg) were
administered intravenously in our separate groups of hydropenic rats. Urine
flow increased by 2.8 +/- 0.3, 4.5 +/- 0.5, 7.7 +/- 0.5, and 18.2 +/- 0.8
microliters/min, respectively, above control values. The rise of urinary
sodium secretion was of similar magnitude and averaged 0.4 +/- 0.1, 0.8 +/-
0.2, 1.1 +/- 0.3, and 2.4 +/- 0.3 mu eq/min, respectively. No significant
change in urinary phosphate excretion was obtained in all groups of rats,
and glomerular filtration rate remained constant from control to
experimental clearance periods. The natriuretic effect of prestegane B
observed in this in vivo model could be related to the inhibition of the
Na+-K+-adenosine triphosphate activity demonstrated in vitro in previous
studies from our laboratory. The action of this substance is likely to be
situated beyond the proximal tubule, since urinary phosphate was not
altered. Prestegane B mimics the effects of other endogenous diuretic and
natriuretic hormones, but its site of action and its effect on renal
hemodynamics are obviously different.
