title: Mechanisms of CO2 transport in rectal salt gland of aedes. I. Ionic requirements of CO2 secretion.
abstract: Rectal salt glands of Aedes dorsalis can be successfully isolated and microperfused in vitro. Microperfused salt glands maintain a large, stable transepithelial potential (-40 to -50 mV, lumen negative) and secrete total CO2 at high and stable rates [CO2 net flux ( JCO2net ) = 799 +/- 57 pmol . min-1 . mm-1]. Bilateral Na+ and K+ or serosal Cl- substitutions and serosal addition of 1.0 mM ouabain, 2.0 mM amiloride, or 0.5 mM 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid had no effect on JCO2net . Removal of luminal Cl- inhibited JCO2net by 80%, whereas serosal addition of 1.0 mM acetazolamide or 0.5 mM 4,4'-diisothiocyano-2,2'-disulfonic acid inhibited JCO2net by 80 and 40%, respectively. Net Cl- reabsorption ( JClnet = -888 +/- 57 pmol . min-1 . mm-1) was equivalent to total CO2 secretion, suggesting that CO2 transport was mediated by a 1:1 exchange of luminal Cl- for serosal HCO-3.
mesh_terms: D000330:Aedes / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D001696:Biomechanical Phenomena; D002245:Carbon Dioxide / Q000378:metabolism*; D007474:Ion Exchange; D007477:Ions; D007814:Larva
chemical_list: D007477:Ions; D002245:Carbon Dioxide