Diuretic and natriuretic properties of prestegane B, a mammalian lignan
Plante, G.E.; Prévost, C.; Chainey, A.; Braquet, P.; Sirois, P.
American Journal of Physiology 253(2 Pt 2): R375-R378
1987
ISSN/ISBN: 0002-9513 PMID: 3039862 Document Number: 299957
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 four 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 .mu.l/min, respectively, above control values. The rise of urinary sodium excretion 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 rat 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 triphosphatase 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.