Vol. 274, Issue 5, H1509-H1515, May 1998
Age-dependent responses of the mesenteric vasculature to
ischemia-reperfusion
Norman R.
Harris and
Kimberly W.
Langlois
Department of Molecular and Cellular Physiology, Louisiana State
University Medical Center, Shreveport, Louisiana 71103
The
age-dependent responses of the mesenteric vasculature to
ischemia-reperfusion (I/R) were compared in 2-mo-old and
2-yr-old rats. Measurements were made of leukocyte adherence, albumin
leakage, and oxidative stress in postcapillary venules. In young rats
I/R induced an increase in leukocyte adherence and albumin leakage, but
in aged rats I/R induced an increase in albumin leakage without an
increase in leukocyte adherence. Furthermore, I/R-induced oxidative stress was higher in the aged rats than in the young rats. To investigate whether the age-associated oxidative stress is related to a
decrease in the role of nitric oxide,
NG-nitro-L-arginine methyl ester
(L-NAME) was superfused onto the mesentery of young and aged rats.
L-NAME induced an increase in postcapillary protein leakage only in young rats; however, arteriolar constriction induced by
L-NAME occurred in
both age groups. These results suggest that different mechanisms
contribute to the inflammatory responses and microvascular dysfunction
elicited by I/R in young and aged rats.
microvascular permeability; aging; endothelial barrier dysfunction
