Journal
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY
Volume 148, Issue 2, Pages 368-373Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.cbpa.2007.05.025
Keywords
eel intestine; nitric oxide; cGMP; Cl- absorption; HCO3- transport; paracellular pathway
Categories
Ask authors/readers for more resources
We investigated the role of NO (nitric oxide) in the isolated intestine of the sea water adapted eel, by testing the effect Of various donors on I-sc (short-circuit current), due to net Cl- absorption in the control conditions. We found that the endogenous NO-synthase substrate L-arginine as well as two different NO donors, SNP (sodium nitroprusside) and SIN-1 (3-morpholinosydnonimine), produced a slow and gradual decrease of I-sc. The effect of SNP was reduced by the pretreatment with ODQ (1H-[1,2,4]oxadiazolo-[4,3-alquilloxalin-1-one), a specific inhibitor of the soluble guanylyl cyclase, suggesting the involvement of cGMP (cyclic GMP) in some physiological actions of NO. The effect of the NO donors on I-sc was similar to that observed when the tissues were perfused with solution in which the HCO3- buffer was substituted with Hepes buffer. In addition the NO donors produced a negligible effect on I-sc when the tissues were perfused with Hepes buffer or in the presence of bilateral SITS(4-Acetoamido-4'-iso-thiocyanatostilbene-2,2'disulphonic acid), an inhibitor of the HCO3- transport mechanisms, operating on both cell membranes of the eel enterocyte and responsible for HCO3- uptake by the cell. Based on these observations we suggest that NO regulates L,, and hence the transepithelial ion transport indirectly by modulating the endocellular concentration of HCO3- and/or H+. In addition it is likely that NO modulates the permeability of the paracellular pathway since SNP produced also an increase of the tissue conductance and a decrease of the magnitude of the dilution potential. (c) 2007 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available