title: Atrial natriuretic peptide and nitroprusside cause relaxation of cultured rat mesangial cells.
abstract: These studies evaluate the effects of atrial natriuretic peptide (ANP) and nitroprusside (NP) on cultured mesangial cells (MC) grown on a flexible silicone rubber surface. The basal tone of the MC produced wrinkles on the silicone rubber surface. A decrease in number or magnitude of wrinkles was considered to represent cell relaxation, whereas an increase represented cell contraction. ANP (10(-9) M) produced a relaxation in greater than 60% of the cells by 10 min. The percentage of cells showing a decrease of wrinkles was significantly higher (P less than 0.05 at 5 min and P less than 0.001 at 10 min) during the ANP-treated period than during the control period. NP (10(-5) M) caused a decrease of wrinkles in greater than 80% of cells (P less than 0.02 at 5 min and P less than 0.01 at 10 min) compared with a 5% decrease in the control period. Dibutyryl guanosine 3',5'-cyclic monophosphate (DBcGMP; 10(-4) M) also produced a decrease of wrinkles in 81% of the cells (P less than 0.02) compared with a 9% decrease in the control period. MC treated with ANP, NP, or DBcGMP and then labeled with 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD)-phallacidin did not show obvious alteration of morphology of actin filaments compared with untreated cells. ANP could inhibit as well as partially reverse the agonist (angiotensin II)-induced contractile response. ANP (10(-10)-10(-8) M) as well as NP (10(-5) M) increased intracellular cGMP content of MC (P less than 0.005) compared with control cells.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, Long Island Jewish Medical Center, New Hyde Park 11042.
authors.forename: P C
authors.initials: PC
authors.lastname: Singhal
authors.forename: S
authors.initials: S
authors.lastname: DeCandido
authors.forename: J A
authors.initials: JA
authors.lastname: Satriano
authors.forename: D
authors.initials: D
authors.lastname: Schlondorff
authors.forename: R M
authors.initials: RM
authors.lastname: Hays
mesh_terms: D000546:Amanitins; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D005292:Ferricyanides / Q000494:pharmacology*; D005456:Fluorescent Dyes; D005920:Glomerular Mesangium / Q000166:cytology* / Q000187:drug effects; D008751:Methylene Blue / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D009599:Nitroprusside / Q000494:pharmacology*; D051381:Rats
chemical_list: D000546:Amanitins; D005292:Ferricyanides; D005456:Fluorescent Dyes; D000804:Angiotensin II; D009599:Nitroprusside; D003995:Dibutyryl Cyclic GMP; C028877:7-nitrobenz-2-oxa-1,3-diazole-phallacidin; D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP; D008751:Methylene Blue