Perfusion with 10 X 10(-6) M atrial natriuretic peptide directly and reversibly increased single capillary hydraulic conductivity in frog mesenteric microvessels by a mean of 3.79-fold.
Does atrial natriuretic peptide increase capillary hydraulic conductivity in frog mesenteric microvessels?
Atrial natriuretic peptide directly and reversibly elevates capillary hydraulic conductivity independent of changes in capillary hydrostatic pressure or surface area.
Effect estimate: 3.79-fold increase
The small molecular weight peptide, atrial natriuretic peptide (ANP), produces marked sodium and water excretion. The peptide, extracted from several species of vertebrate heart, also has been shown to increase glomerular filtration and reduce plasma volume. Several mechanisms have been proposed to account for the action of the peptide but remain undefined. In the present report, the ANP-induced alterations in transcapillary water movement were directly assessed. The modified Landis technique was used to measure single capillary hydraulic conductivity (Lp) of vessels from the frog mesenteric circulation. In 6 individual microvessels, Lp was measured under control conditions and again during perfusion with 10 X 10(-6) M ANP. The Lp increased in each vessel by a mean of 3.79-fold (+/- 2.09 SD). In 4 of these vessels, an additional measurement of Lp was repeated under control conditions; the capillary filtration coefficient returned to control levels. It was concluded that ANP directly and reversibly elevates capillary hydraulic conductivity; this response is independent of changes in capillary hydrostatic pressure or surface area.
Huxley et al. (Sun,) reported a other. Atrial natriuretic peptide (ANP) vs. Control conditions was evaluated on Single capillary hydraulic conductivity (Lp) (3.79-fold increase). Perfusion with 10 X 10(-6) M atrial natriuretic peptide directly and reversibly increased single capillary hydraulic conductivity in frog mesenteric microvessels by a mean of 3.79-fold.