title: Mechanism of action and structural requirements of vasopressin analog inhibition of transepithelial water flux in toad urinary bladder.
abstract: Vasopressin, vasopressin analogs, forskolin and 8-bromo-cyclic AMP (8Br-cAMP) were studied for their effects on transepithelial water flux in toad urinary bladder. Arginine vasopressin, arginine vasotocin, oxytocin, desamino-8-D arginine vasopressin, forskolin and 8Br-cAMP stimulated hydro-osmotic water flux in a dose-dependent fashion. The rank order of potency was arginine vasotocin greater than arginine vasopressin greater than oxytocin greater than desamino-8-D-arginine vasopressin greater than forskolin greater than 8Br-cAMP. The vasopressin analogs [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-(O-methyl)tyrosine,8-arginine]vasopressin (SK&F 100273), [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-(O-methyl)tyrosine,4-valine,8-arginine]vasopressin (SK&F 100501), [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-D-tyrosine,4-valine,8-arginine]vasopressin (SK&F 100885), [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-(O-ethyl)tyrosine,4-valine,8-arginine]vasopressin (SK&F 100398), [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-D-isoleucine,4-valine,8-arginine]vasopressin (SK&F 101485), [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-(O-ethyl)-tyrosine,4-valine,8-arginine]vasopressin (SK&F 101498), [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-(O-ethyl)D-tyrosine,4-valine,8-arginine,9-desglycine]vasop ressin (SK&F 101926) and [1-(beta-mercapto-beta-beta-cyclopentamethylene propionic acid),2-D-phenylalanine,4-valine,8-arginine] vasopressin (SK&F 101071) antagonized arginine vasopressin-stimulated water flux and displaced the agonist dose-response relationship to the right in a parallel fashion. The most potent antagonists were those having the (O-ethyl)-D-tyrosine substitution at position 2. None of the antagonists tested had any effect on 8Br-cAMP-stimulated water flux at concentrations up to 10(-6)M.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D001834:Body Water / Q000378:metabolism*; D002024:Bufo marinus; D005576:Colforsin / Q000494:pharmacology; D004848:Epithelium / Q000378:metabolism; D066298:In Vitro Techniques; D011945:Receptors, Angiotensin / Q000187:drug effects; D017483:Receptors, Vasopressin; D013045:Species Specificity; D013329:Structure-Activity Relationship; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism*; D014667:Vasopressins / Q000037:antagonists & inhibitors / Q000494:pharmacology*
chemical_list: D011945:Receptors, Angiotensin; D017483:Receptors, Vasopressin; C034862:vasotocin receptor; D014667:Vasopressins; D001127:Arginine Vasopressin; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate