Abstract
Studies were made on the relation between the skin potential response (SPR) and sweat output of cat foot pads. With weak stimulation of the lateral planter nerve, both the SPR and sweat output increased with increase in the stimulus, but in supra-maximal stimulation, the SPR remained constant and only the sweat output increased. When blood circulation was withheld by ligation of the femoral vessels, sweat output decreased to zero within an hour, whereas the SPR was affected only slightly.
During perfusion of the foot with modified Ringer solution of various compositions, it was observed that the SPR was very susceptible to increase in the K+ ion concentration in the perfusate in contrast to slight effects produced by replacement of NaCl with sucrose or by replacement of Cl- with SO4--.
From these results, it seems that the SPR of cat foot pads is caused by change in the membrane permeability of the sweat gland to potassium ion.
