Involvement of nitric oxide in 5-HT(3) receptor agonist-induced fluid accumulation in jejunum and colon of anesthetized rats.
OBJECTIVE
The aim of the present study was to investigate the involvement of nitric oxide in 5-HT(3) receptor agonist-induced fluid accumulation in jejunum and colon of anesthetized rats.


METHODS
Fluid movement in jejunum and colon were determined simultaneously in the same rat, by modifying the Beubler method. Nomega-nitro-L-arginine (L-NNA, 20 mg/kg, s.c) alone and in combination with L-arginine (L-Arg, 150 mg/kg s.c) or D-arginine (D-Arg, 150 mg/kg, s.c) were administered 30 min before administration of 1-PBG (18.5 mug/kg, i.v).


RESULTS
Intravenous administration of 1-phenylbiguanide (1-PBG) induced a net secretion of fluid in both jejunum and colon. 1-PBG had a more prominent secretory effect in the colon, causing a three-fold increase in volume of fluid secreted/g of colon than in the jejunum. Pretreatment with (L-NNA) prevented the 1-PBG-induced fluid accumulation in both jejunum and colon. The inhibitory effect of L-NNA on 1-PBG-induced fluid accumulation was reversed by L-Arg but not by D-Arg.


CONCLUSIONS
These results provide evidence that nitric oxide plays an important role in 5-HT(3) receptor agonist-induced fluid accumulation in jejunum and colon of anesthetized rats.
Veeresh
B
B
Department of Pharmacology, K.L.E.Ss College of Pharmacy, J.N.M.C. Campus, Nehru Nagar, Belgaum - 590 010, India.
Patil
Basanagouda M
BM
Veeresh Babu
S V
SV
Jeedi
Neelakanth M
NM
Unger
Banappa S
BS