ALLOXAN-DIABETES CAUSES OXIDATIVE IMBALANCE AND MORPHOLOGICAL, MORPHOMETRIC AND ULTRASTRUCTURAL CHANGES IN RAT LUNGS

Olivia A. Xavier Suarez MD, PhD., Amanda Natália Lucchesi BS, PhD., Antônio José M. Catâneo MD, PhD., *César Tadeu Spadella MD, PhD.

ABSTRACT

Purpose: This study evaluated the long-term effects of alloxan-induced diabetes in rat lungs. Method: Sixty non-diabetic control (NC) and 60 untreated diabetic (UD) rats were divided into 3 subgroups and sacrificed after 6, 14, or 26 weeks. Results: UD rats showed clinical and laboratory signs of severe diabetes throughout the study. Fresh and fixed lung weight, fixed lung volume, and lung compliance were significantly reduced in UD rats, whereas fresh lung weight relative to body weight was higher after 14 and 26 weeks. LPO free radicals were significantly higher in the pulmonary tissue of UD rats, whereas SOD, CAT, and GSH-Px antioxidant enzyme activities were lower after 14 and 26 weeks. UD rats showed lung morphological changes characterized by diminution of alveolar spaces with alveolar septa thickening and varying degrees of congestion, insudation, and interstitial mononuclear inflammatory infiltrate. Morphometric analysis revealed that the total number of alveoli and alveolar and endothelial basal laminae thickness were significantly higher in UD than NC rats, whereas alveolar perimeter and alveolar surface area were decreased. Ultrastructural changes were observed in all structures of UD alveolar septa and included alveolar and capillary lumen narrowing, type I cell degeneration, expansion of interstitial extracellular matrix by edema and abundant pynocytotic vesicles, and diminution of type II cell microvilli, which had a high amount of mature lamellar corpuscles with a delay in their surfactant output out of the cytoplasm. Conclusions: Alloxan-diabetes causes morphological, morphometric and ultrastructural changes in rat lungs. These changes may be correlated to oxidative imbalance caused by persistent hyperglycemia.

Keywords: Diabetes Mellitus. Alloxan Diabetes. Diabetic Chronic Lesions. Pulmonary Changes. Morphology. Ultrastructure.