Effect of arterial perfusion on net water flux and active sodium transport across the isolated skin ofBufo bufo bufo (L.)

Summary

A method has been developed which allows perfusion of the blood vessels in isolated pelvic skins ofB. bufo. The effect of various doses of vasotocin (AVT) on net water flux (inside medium 220 mOsM, outside medium 11 mOsM) and active sodium transport were compared in perfused and unperfused skins. The unstimulated water flux (Fig. 3) and the active sodium transport (Fig. 6) were unaffected by perfusion. The threshold for stimulation of water flux was between 0.01 and 0.1 nM vasotocin in perfused skins and between 0.1 and 1 nM in unperfused skins. The threshold for stimulation of active sodium transport was between 0.005 and 0.05 nM vasotocin in perfused skins and between 0.05 and 0.5 nM in unperfused skins. The maximal water flux through perfused skins, 4 μl/cm²min, was obtained at 1 nM vasotocin. At 10 nM vasotocin the water flux was only 0.7 μl/cm²min in unperfused skins. The maximal active sodium transport was approximately of the same magnitude in perfused and unperfused skins, at 0.5 mM and at 50 nM, respectively.