The nature of Cl- secretion, induced by carbaryl, across the isolated skin of Rana esculenta.
1. The pesticide carbaryl induces Cl- secretion through the isolated frog skin. 2. This effect is due to the activation of both processes responsible for this phenomenon: (a) Na+/K+/2Cl- cotransport on the serosal membrane; (b) Cl- selective channels on the external membrane. 3. Cl- outflux is inhibited by bumetanide (10(-5) M) on the serosal side and by diphenylamine-2-carboxylic acid (DPC) (10(-3) M) on the external side. 4. The DPC action is not mimicked by Naproxen, a specific inhibitor of cyclooxygenase. 5. A comparison with isoprenaline, demonstrates that the carbaryl action is, paradoxically, more selective than that of isoprenaline. 6. This selectivity of carbaryl action on Cl- permeability is confirmed by the fact that, unlike isoprenaline, carbaryl does not affect the permeability of Na+ and thiourea.
Institute of General Physiology, University of Bari, Italy.
C
C
Lippe
V
V
Bellantuono
G
G
Valenti
C
C
Ardizzone
D000818:Animals; D002034:Bumetanide / Q000494:pharmacology; D012721:Carbaryl / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D011893:Rana esculenta; D012867:Skin / Q000187:drug effects* / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters; D062367:ortho-Aminobenzoates / Q000494:pharmacology
D002352:Carrier Proteins; D018118:Chloride Channels; D002712:Chlorides; D008565:Membrane Proteins; D028021:Sodium-Potassium-Chloride Symporters; D062367:ortho-Aminobenzoates; D002034:Bumetanide; C001209:fenamic acid; D007545:Isoproterenol; D012721:Carbaryl