Abstract
The permeability of single subcutaneous microvessels in the frog skin was determined with electrophysiological techniques after only minimal surgical intervention. The organization of blood vessels in the frog skin is described at the microscopic level. Transmission electron microscopy showed that the subcutaneous microvessels belong to the class of “continuous” vessels ( H. Bennett, J. Luft, and J. Hampton, 1959, Amer. J. Physiol. 196, 381–390). Capillaries in the true sense of the word are rare in this subcutaneous tissue. The electrical resistance of the endothelium in well defined segments of the subcutaneous microvessels was determined by means of current injection and voltage recording microelectrodes using cable theory for the analysis. The average resistances were 70 and 24 Ω · cm 2 for arterioles and venules, respectively; the mean values of the two groups were significantly different ( P < 0.001). These figures are close to those obtained on microvessels in skeletal muscle ( S.-P. Olesen and C. Crone, 1983, Biophys. J. 42, 31–41), but are about one order of magnitude higher than resistances of mesenteric microvessels. The calculated sodium permeabilities were for arterioles: P Na + = 1.6 × 10 −5 cm sec −1 and for venules: 4.6 × 10 −5 cm sec −1.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call