Atrial natriuretic peptide effect on NADPH-diaphorase in rat intestinal tract.
Histochemical reaction of NADPH-diaphorase (NOS-NADPH-d) was used to identify NO synthesis. A 30-min 0.1 microg microg/kg/min ANP infusion led to about a 10% and 35% increase in small and large intestine enterocytes stain respectively. This increase was abolished by a bolus of 1 mg/kg L-NAME before ANP infusion in small intestine, and partially abolished it in colon. Incubation of small and large intestine with 0.5 microM ANP increased stain at about 20%. In both tissues the preincubation with 0.1 mM L-NAME abolished the ANP effect. Incubation with 0.1 mM 8-Br-cGMP enhanced staining about 70% and 30% in small and large intestine respectively. Our results show that ANP enhances NOS-NADPH-d activity, suggesting that ANP stimulates NO synthase in enterocytes by L-arginine-NO pathway. 8-Br-cGMP mimicked the effect of ANP described above. Therefore, the guanylate cyclase-coupled natriuretic receptors, NPR-A and NPR-B, probably mediate this ANP effect.
González Bosc
L V
LV
Biología Celular e Histología, Facultad de Farmacia y Bioquímica, UBA, Argentina. lgbosc@huemul.ffyb.uba.ar
Capani
F
F
López-Costa
J J
JJ
Ortiz
M C
MC
Majowicz
M P
MP
Costa
M A
MA
Arranz
C T
CT
Balaszczuk
A M
AM
Pecci Saavedra
J
J
Vidal
N A
NA
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D003106:Colon / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism; D006651:Histocytochemistry; D007091:Image Processing, Computer-Assisted; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D007421:Intestine, Small / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D007527:Isoenzymes; D008297:Male; D009252:NADPH Dehydrogenase / Q000032:analysis*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase; D017440:Photoperiod; D051381:Rats; D017208:Rats, Wistar; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism; D000099242:Atrial Natriuretic Factor Receptor B
D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP; D006162:Guanylate Cyclase; D007527:Isoenzymes; D009252:NADPH Dehydrogenase; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D017461:Receptors, Atrial Natriuretic Factor; D000099242:Atrial Natriuretic Factor Receptor B; C016276:8-bromocyclic GMP; C091715:atrial natriuretic factor receptor A