title: Trypsin affects basal and stimulated osmotic water permeability in isolated toad skin.
abstract: 1. We investigated the effect of trypsin (Tryp) on basal, stimulated and fluphenazine (FPZ)-inhibited net water flow (Jw) through isolated toad skin (Bufo arenarum). 2. Epidermal Tryp (20 min) promoted an increase in basal Jw which was dose-dependent (maximal with 0.5 mg/ml) and was prevented by a Tryp inhibitor (SBTI). 3. Tryp treatment inhibited the subsequent response to substances known to act before (oxytocin, Oxy) or after cyclic AMP (cAMP) generation (theophylline). 4. Tryp-induced Jw was not additive with the maximal response to Oxy or theophylline and did not modify FPZ's inhibitory effect on stimulated Jw. 5. Dermal Tryp (0.5 mg/ml, 20 min) did not modify basal, but inhibited Oxy and isoproterenol-stimulated Jw, without altering the response to theophylline or db-cAMP. 6. Collectively, our results show a differential action for epidermal and dermal Tryp. Tryp's side-selective action enables its use as a pharmacological tool in the functional dissection of Jw across toad skin.
authors.affiliation: Department of Physiology, INSIBIO, CONICET-UNT, San Miguel de Tucumán, Argentina.
authors.forename: D M
authors.initials: DM
authors.lastname: Berman
authors.forename: M O
authors.initials: MO
authors.lastname: Soria
authors.forename: A
authors.initials: A
authors.lastname: Coviello
mesh_terms: D000818:Animals; D002022:Bufo arenarum / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D005260:Female; D005476:Fluphenazine / Q000494:pharmacology; D008297:Male; D009995:Osmosis / Q000187:drug effects; D010539:Permeability; D012867:Skin / Q000378:metabolism*; D013268:Stimulation, Chemical; D014357:Trypsin / Q000494:pharmacology*; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water; D014357:Trypsin; D005476:Fluphenazine