Decrease of nitric oxide synthase in the cerebrocortex of streptozotocin-induced diabetic rats.
In an attempt to know the role of nitric oxide in the disease of insulin-dependent diabetic mellitus (IDDM), the present study examined the change of nitric oxide synthase (NOS) both the activity and gene expression in cerebrocortex of streptozotocin-induced diabetic rats (STZ-diabetic rats). The activity of NOS determined by conversion of [3H] L-arginine to [3H] L-citrulline was markedly decreased in STZ-diabetic rats. Northern blot showed that STZ-diabetic rats expressed a lower mRNA level of neuronal NOS (nNOS). Western blot showed a similar decrease of nNOS in STZ-diabetic rats. However, the NOS activity was increased in rats receiving repeated supply of glucose named glucose-challenged rats. Although the mRNA level of nNOS was not changed in the glucose-challenged rats, the immunoblot of nNOS was also decreased in glucose-challenged rats. These findings suggested that NOS was lowered in the brain of STZ-diabetic rats in a way unrelated to the increase of glucose.
Yu
W J
WJ
Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan City, Taiwan.
Juang
S W
SW
Chin
W T
WT
Chi
T C
TC
Wu
T J
TJ
Cheng
J T
JT
D000818:Animals; D015152:Blotting, Northern; D002540:Cerebral Cortex / Q000201:enzymology*; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D012333:RNA, Messenger; D051381:Rats; D017208:Rats, Wistar
D012333:RNA, Messenger; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; C496322:Nos1 protein, rat; C496318:Nos2 protein, rat