Impaired endothelium-dependent and neurogenic relaxation of corpus cavernosum from diabetic rats: improvement with L-arginine.
This study describes the relaxant response to acetylcholine, electrical field stimulation and sodium nitroprusside after contraction by phenylephrine (10(-5) M) in corpus cavernosum from control and diabetic rats. The response to acetylcholine (10(-9)-10(-3) M) and electrical field stimulation (0.5-64 Hz) is decreased and can be restored by the addition of nitric oxide synthetase substrate, L-arginine(10(-5) M). The response to sodium nitroprusside is not changed in diabetic rats compared to control rats. NADPH-diaphorase staining was enhanced in a diabetic preparation compared to control preparations. The findings suggest a role for the depletion of L-arginine in diabetes mellitus. The enhanced NADPH-diaphorase staining may be due to a deficiency of NOS substrate L-arginine in the endothelium and nerves of diabetic tissues.
Gür
S
S
Ankara Universitesi, Eczacilik Fakültesi, Farmakoloji Anabilim Dali, Turkey. sgur@pharmacy.ankara.edu.tr
Oztürk
B
B
Karahan
S T
ST
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004727:Endothelium / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000503:physiopathology*; D010413:Penis / Q000187:drug effects / Q000294:innervation / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D001120:Arginine; D000109:Acetylcholine