AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 3 639-R642, Copyright © 1986 by American Physiological Society
Trout vascular and renal responses to atrial natriuretic factor and heart extracts
D. W. Duff and K. R. Olson
Dorsal aortic pressure (DAP), urine flow rate, and urinary K+, Na+, and Cl-
were monitored in chronically catheterized unanesthetized rainbow trout
before and after injection of saline, tissue extracts, or synthetic (rat,
Ile-26) atrial natriuretic factor (ANF). Synthetic ANF (1.0 and 10.0
micrograms/kg body wt) and extracts from trout atria and ventricles
increased DAP, urine flow rate, and electrolyte excretion. Saline, skeletal
muscle extracts, and 0.1 microgram/kg body wt synthetic ANF had no effect
on DAP and only minor effects on renal water and ion excretion. The
slow-onset long-duration pressor response to ANF and heart extracts
contrasted with a rapid short-acting pressor effect of epinephrine.
Synthetic ANF (10 micrograms/kg body wt) and ventricular extracts produced
marked increases in Na+ and Cl- excretion but only a mild diuresis. Much of
the increase in urine flow rate appears to be due to solvent injection.
These results show that trout hearts contain an ANF-like material and that
mammalian and piscine ANF produce hemodynamic and renal effects upon
intra-arterial injection.
