Influence of insulin treatment on the lacrimal gland and ocular surface of diabetic rats.
Previous studies have observed changes in the lacrimal gland and ocular surface related to diabetes mellitus and related it to insulin resistance or insufficiency and oxidative damage. The aim of this study was to evaluate whether insulin treatment inhibits those changes. Diabetes was induced in male Wistar rats with a single intravenous injection of streptozotocin and a subgroup was treated with insulin. After 5 and 10 weeks, the three groups (n = 5-10/group/experimental procedure) were compared for biochemical, functional, and histological parameters. After 5 weeks, changes in morphology and increased numbers of lipofucsin-like inclusions were observed in lacrimal glands of diabetic but not insulin-treated rats. After 5 weeks, malonaldehyde and total peroxidase activity were significantly higher in diabetic rats, but similar to control in insulin-treated diabetic rats (P = 0.03, P = 0.02, respectively). Our data indicate that diabetes induces histological alterations in lacrimal gland and suggests that hyperglycemia-related oxidative stress may participate in diabetic dry eye syndrome. Prevention by insulin replacement suggests direct hormone action and/or benefit by early sub optimal metabolic control.
Módulo
Carolina Maria
CM
Department of Ophthalmology, University of São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, SP, 14049-900, Brazil.
Jorge
Angélica Gobbi
AG
Dias
Ana Carolina
AC
Braz
Alexandre Martins
AM
Bertazolli-Filho
Rubens
R
Jordão
Alceu A
AA
Sérgio Marchini
J
J
Rocha
Eduardo M
EM
D000818:Animals; D003315:Cornea / Q000187:drug effects / Q000473:pathology; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy*; D015352:Dry Eye Syndromes / Q000139:chemically induced* / Q000473:pathology; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007275:Injections, Intravenous; D007328:Insulin / Q000494:pharmacology*; D007765:Lacrimal Apparatus / Q000187:drug effects* / Q000473:pathology; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D007004:Hypoglycemic Agents; D007328:Insulin