title: The effects of perfusion of the cutaneous vasculature on sodium uptake across isolated frog skin.
abstract: Perfusion of cutaneous capillaries in isolated frog skin may remove an unstirred layer along the basolateral membrane of the epidermis that may affect the rate of cutaneous Na(+) uptake. To test this hypothesis, the cutaneous artery and vein of a bullfrog were cannulated to allow perfusion of isolated flank skin while the rate of Na(+) influx was determined. Rates of sodium influx with and without perfusion were determined in the same experiment. Na(+) uptake increased by 59+/-4.8% during the 1st 0.5 h of perfusion relative to the control, pre-perfusion period and then remained at 26+/-5.3% above control values. Concomitant with the increase in sodium uptake, the transepithelial potential difference fell by ca. 10% within the 1st 0.5 h of perfusion. The amount of labeled sodium leaving the skin in the venous effluent decreased exponentially in the 1st 0.5 h of perfusion, suggesting a wash out of an unstirred layer within the interstitial fluid. Sodium in the venous outflow accounted for ca. 25% of the sodium uptake during each perfusion period. Perfusion of the cutaneous vasculature thus has a significant effect on Na(+) transport and may potentially play a role in the acute regulation of cutaneous ion transport.
authors.affiliation: Department of Biology, California State University, 5500 University Parkway, San Bernardino, CA 92407, USA. ctalbot@csusb.edu
authors.forename: R
authors.initials: R
authors.lastname: Talbot
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002196:Capillaries / Q000378:metabolism; D066298:In Vitro Techniques; D008196:Lymph / Q000378:metabolism; D010477:Perfusion; D011892:Rana catesbeiana; D012867:Skin / Q000098:blood supply* / Q000378:metabolism*; D012964:Sodium / Q000493:pharmacokinetics*; D014680:Veins / Q000378:metabolism
chemical_list: D012964:Sodium