CONICET | Buscador de Institutos y Recursos Humanos

Hemeoxygenase-1 (HO-1) is highly sensible to all kinds of stimuli inducing oxidative stress and many diseases. Its expression is increased in tumoural cells and can be further enhanced as a response to Photodynamic Therapy. The marker event for development of diabetes mellitus type I, is the destruction of insulin-secreting pancreatic â cells. Our aim was to study the morphological, functional and expression alterations of HO-1 in diabetic mice pancreas. CF1 male mice (20 g) turned diabetics with a single dose of streptozotocin (STZ)(170 mg/Kg,ip), taking blood glucose levels above 300 mg/ml, mice were sacrificed at day 21(STZ21) and 32(STZ32). Controls received vehicle. Pancreas were fixed in formalin and embedded in paraffin for histological and immunohistochemical studies. Insular area (IA) was calculated. Controls: islets, acini and ducts were preserved (IA:4.52±0.49). STZ21: islets were medium size with small and basophilic nuclei (IA:3.28±0.63). STZ32: islets were of different sizes and shapes (IA:2.17±0.58), nucleous-cytoplasmic acinar cells were altered. Insulin immunostain in the islet cells of both STZ21 and STZ32 groups, compared with control, decreased by 30 and 50% respectively, while Glucagon immunostain increased 30%. The regulatory region 5 of HO-1 gene, has binding sites for transcription factor SP1, involved in its activation. Controls: HO-1 was positive in most islet cells, SP1 was expressed in 80-90% of them. STZ21: increase in the markup for HO-1 and SP1 was observed. Control and STZ21: acinar and ductal immunostain was negative for HO-1 and SP1. STZ32: HO-1 was negative in islet cells, SP1 was slightly positive. Moderate to intense HO-1 and SP1 immunostain was found in morphologically altered acini.