Fructose-1,6-biphosphate in rat intestinal preconditioning: involvement of nitric oxide.
OBJECTIVE
Inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by nitric oxide (NO) in intestinal preconditioning could modify the rate of formation of glycolytic intermediates. Fructose-1,6-biphosphate (F16BP) is a glycolytic intermediate that protects tissue from ischaemia/reperfusion injury. We evaluated if F16BP may be endogenously accumulated as a consequence of GAPDH inhibition by NO during intestinal preconditioning in rats.


METHODS
We assessed: (1) effect of preconditioning on F16BP content; (2) effect of NO on GAPDH activity before and during sustained ischaemia; and (3) protective effect of F16BP in control, ischaemic, and preconditioned animals with or without administration of N-nitro-L-arginine methyl ester (L-NAME), NO donor, or F16BP.


RESULTS
Preconditioned rats showed a significant transient decrease in GAPDH activity and also maintained basal F16BP levels longer than ischaemic rats. L-NAME administration to preconditioned rats reversed these effects. F16BP administration to ischaemic rats decreased protein release in the perfusate. Administration of F16BP to L-NAME treated rats attenuated the harmful effect of L-NAME.


CONCLUSIONS
Our study indicates that F16BP may be endogenously accumulated in preconditioned rats as a consequence of inhibition of GAPDH by NO, and this may contribute to the protection observed in intestinal preconditioning.
Sola
A
A
Department of Medical Bioanalysis, Instituto de Investigaciones Biomédicas de Barcelona (IIBB-CSIC-IDIBAPS), C/Roselló 161, 7(a) planta, Barcelona, Spain.
Roselló-Catafau
J
J
Gelpí
E
E
Hotter
G
G
D000704:Analysis of Variance; D000818:Animals; D005636:Fructosephosphates / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000037:antagonists & inhibitors / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000098:blood supply*; D019194:Ischemic Preconditioning; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D005636:Fructosephosphates; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D019331:NG-Nitroarginine Methyl Ester