Elevation of an endogenous inhibitor of nitric oxide synthase in diabetic rat serum
Abstract
AIM: To study the endogenous inhibitor of NO synthase NG,NG-dimethyl-arginine
(DMA) in the diabetic rat serum.
METHODS: In streptozocin-induced diabetic rats, the serum DMA level and
endothelium-dependent vasorelaxation to acetylcholine (ACh) were determined.
RESULTS: The serum DMA concentration was increased in the diabetic rats compared
with their age-matched controls (5.4 +/- 1.0 vs 0.7 +/- 0.3 mumol.L-1, P < 0.01).
The serum malondialdehyde (MDA) level was also increased in the diabetic rats
compared with controls (2.5 +/- 0.3 vs 1.5 +/- 0.1 mumol.L-1, P < 0.01).
Vasodilator response to ACh was impaired in diabetic thoracic aortas, which was
improved by preincubation with L-arginine 1 mmol.L-1.
CONCLUSION: Hyperglycemia elevated the endogenous DMA content, which contributed
to attenuated endothelium-dependent vasorelaxation in streptozocin-induced
diabetic rats.
Keywords:
(DMA) in the diabetic rat serum.
METHODS: In streptozocin-induced diabetic rats, the serum DMA level and
endothelium-dependent vasorelaxation to acetylcholine (ACh) were determined.
RESULTS: The serum DMA concentration was increased in the diabetic rats compared
with their age-matched controls (5.4 +/- 1.0 vs 0.7 +/- 0.3 mumol.L-1, P < 0.01).
The serum malondialdehyde (MDA) level was also increased in the diabetic rats
compared with controls (2.5 +/- 0.3 vs 1.5 +/- 0.1 mumol.L-1, P < 0.01).
Vasodilator response to ACh was impaired in diabetic thoracic aortas, which was
improved by preincubation with L-arginine 1 mmol.L-1.
CONCLUSION: Hyperglycemia elevated the endogenous DMA content, which contributed
to attenuated endothelium-dependent vasorelaxation in streptozocin-induced
diabetic rats.