Sodium and Potassium Electrolytes and “ Basal ” Skin Potential Levels in Male and Female Subjects

Abstract

Summary When palmar skin potential level (SPL) is recorded duringperiods of minimal arousal sweating, and a concentration of potassium chloride within physiological limits is used for the external electrolyte, the value of the "basal" SPL (BSPL) recorded can be expressed as a function of the external/epidermal potassium concentration gradient.The present study reports comparison of BSPL values obtained with the use of physiologically comparable concentrations of sodium and potassium chlorides. The results suggest the possibility that the BSPL methodology may provide a means of monitoring electrolyte shifts in the human subject.In addition, sex differences in BSPL values were demonstrated.Palmar skin potential level (SPL) is one of the electrodermal measures that can be recorded from human subjects and used to assess their psychophysiological state (VENABLES and MARTIN, 1967a); human SPL is usually negative at a palmar surface electrode with reference to an "inactive" electrode site on an ipsilateral, abraded, forearm surface. The electrodes used may be of a silver/silver chloride (Ag/AgCl) chamber type, with sodium or potassium chloride (NaCl, KCl) as the external electrolyte at the two electrode/epidermal interfaces (VENABLES and SAY-ER, 1963). The negativity of SPL decreases with decreasing arousal (LEIDERMAN and SHAPIRO, 1964;CHRISTIE, 1970), a condition in which palmar sweating is reduced (MARTIN and VENABLES, 1966) if ambient temperatures are moderate (NEUMANN, 1968, p. 110). The absolute value of SPL has, however, been reported to be lowered when the concentration of the external electrolyte is reduced (VENA-BLES and SAYER, 1963;ROTHMAN, 1954;EDELBERG, 1963).Examination of the physiological mechanisms underlying electrodermal phenomena has suggested that sudorific factors may be significantly implicated in the generation of SPL (MARTIN and VENABLES, 1966): VENABLES and MARTIN

The origin of skin-stretch-caused motion artifacts under electrodes

“…This skin impedance results from two electrical pathways: one through the extracellular channels in the epidermis and one through the sweat ducts. Christie and Venables (1971) have shown that during resting conditions sweat glands are minimally active. Thus we believe that at rest most of the current flows primarily through the extracellular channels in the epidermis and little through the sweat gland ducts.…”

“…Measured with respect to the body interior the skin potential ranges between 10 mV and −70 mV with an average value of −15 mV on the forearm. Christie and Venables (1971) have related this basal skin potential level (BSPL) to the Nernst equation, with K + the most important diffusing ion across the semipermeable membrane:…”

Effect of anodal and cathodal microamperage direct current electrical stimulation on injury potential and wound size in guinea pigs

“…The second reason may be the mechanisms that produce the basal skin potential. These mechanisms are multiple and complex and include epidermal membranes, "skin battery" (voltage across the epidermis), sweat glands, and some diffusion and active-pumping mechanisms [13][14][21][22]33]. As a result, the return of wound potential to preinjury levels is a more prolonged and complex process that occurs slower than wound closure.…”

“…Skin potential has typically been studied through transcutaneous potential measurement (the potential difference between the outer skin surface and the inner skin layers), which is an invasive method [14][15][21][22]]. An electrode must be inserted into the skin and another movable electrode placed on the skin.…”