The relationship between nitric oxide and leptin in the lung of rat with streptozotocin-induced diabetes.
Lung structural changes and immunoreactivity of endothelial (eNOS)- and inducible nitric oxide synthase (iNOS) were investigated by light microscopy in lungs of treated and untreated diabetic rats. Diabetes was induced by a single intraperitoneal (i.p.) injection of 65 mg kg(-1) streptozotocin (STZ) in Wistar albino male rats. Diabetic rats received daily i.p. doses of dexamethasone (2 mg kg(-1)), leptin (0.5 microg kg(-1)) and intramuscular insulin (20 U kg(-1)) or a combination of these drugs for 1 week starting 4 weeks after the STZ injections. After treatment, the blood levels of glucose, leptin, insulin and nitrate/nitrite (NO(3) (-)/NO(2) (-)) were measured. Dilatation of alveoli and alveolar ducts, partial alveolar wall thickening and increased eNOS- and iNOS characterized the diabetic rat lungs. High blood glucose and nitrate/nitrite levels as well as low insulin and leptin levels were also present. Treatment with insulin, dexamethasone and a combination of these drugs resulted in improvement of the structural and immunohistochemical abnormalities. The most effective treatment was insulin therapy. Leptin administration resulted in increased relative amounts of extracellular material, which led to noticeable respiratory efficiency in the diabetic rat lungs. All treatments except leptin lowered blood glucose levels. The combination of insulin and dexamethasone increased blood leptin and insulin, while the remaining diabetic rats had blood with low leptin and insulin concentrations. These results suggest that therapy with insulin plus dexamethasone but not therapy with leptin is beneficial for diabetics.
Oztay
Fusun
F
Department of Biology, Faculty of Science, Istanbul University, Vezneciler, Istanbul, Turkey. fusunoztay@yahoo.com
Kandil
Asli
A
Gurel
Ebru
E
Ustunova
Savas
S
Kapucu
Aysegul
A
Balci
Huriye
H
Akgun-Dar
Kadriye
K
Demirci
Cihan
C
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003907:Dexamethasone / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000097:blood* / Q000139:chemically induced / Q000188:drug therapy; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D007274:Injections, Intraperitoneal; D007328:Insulin / Q000008:administration & dosage* / Q000097:blood; D020738:Leptin / Q000008:administration & dosage / Q000097:blood*; D008168:Lung / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009569:Nitric Oxide / Q000097:blood*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D009573:Nitrites / Q000097:blood; D011650:Pulmonary Alveoli / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin
D001786:Blood Glucose; D007328:Insulin; D020738:Leptin; D009573:Nitrites; D009569:Nitric Oxide; D013311:Streptozocin; D003907:Dexamethasone; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III