Effect of insulin on nitric oxide synthase-like immunostaining of arteries in various organs in Zucker diabetic fatty rats.
OBJECTIVE
Recently we reported that insulin treatment improved hypertension by inducing nitric oxide synthase (NOS) in Zucker diabetic fatty (ZDF) rats. In the present study, we investigated subtypes of NOS induced by insulin in arteries in various organs of ZDF rats using immunohistochemistry.


METHODS
Following treatment with insulin, localization of two subtypes of NOS in the arterial tissues of various organs was identified.


METHODS
Following 4 weeks of s.c. injection of insulin, the aorta, cerebral cortex, pancreas and kidney were stained with polyclonal anti-endothelial NOS (eNOS) or anti-inducible NOS (iNOS) antibodies.


RESULTS
In the aortic tissue, eNOS-like immunostaining was observed equally in the insulin-treated group and the control group, whereas iNOS-like immunostaining was present more densely in the insulin-treated group. In the cerebral artery, eNOS-like immunostaining was observed in the endothelium and was enhanced in the insulin-treated group. In the control group, iNOS-like immunostaining was absent in the cerebral artery, whereas immunostaining was densely observed in the insulin-treated group. In the interlobular artery of the pancreas, both eNOS-like and iNOS-like immunostaining was present in the control group and was enhanced in the insulin-treated group. In kidney, both eNOS-like and iNOS-like immunostaining was more densely present in the arterial tissue of the insulin-treated group.


CONCLUSIONS
These results taken together suggest that insulin treatment induced NOS in arteries in various organs and that iNOS was more strongly induced than eNOS by insulin treatment in the ZDF rat.
Kawaguchi
M
M
First Division, Department of Medicine, Shimane Medical University, 89-1 Enya-cho, Izumo 693-8501, Japan. k-mikiko@shimane-med.ac.jp
Koshimura
K
K
Sohmiya
M
M
Murakami
Y
Y
Gonda
T
T
Kato
Y
Y
D000818:Animals; D001011:Aorta / Q000201:enzymology; D001158:Arteries / Q000201:enzymology*; D002536:Cerebral Arteries / Q000201:enzymology; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000201:enzymology*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000201:enzymology*; D004730:Endothelium, Vascular / Q000201:enzymology; D007150:Immunohistochemistry; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D007668:Kidney / Q000098:blood supply; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000032:analysis*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D009765:Obesity; D010179:Pancreas / Q000098:blood supply; D051381:Rats; D011924:Rats, Zucker
D007328:Insulin; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat