Untitled

Abstract

Induction of diabetes by alloxan cause damage to the pancreatic β-cells and produces typical diabetes signs together with complications involving several organs such thymus. We have used this diabetic model to sought the importance of thymus on susceptibility infection, one of the typical aspect in this condition. We observed that the usual alloxan dosage (75 mg/kg) induced a marked number of deaths in a short period (< 15 days). However, with 60 mg/Kg, the mice were alive for more than 30 days, enough time to evaluate the chronic infectious aspects. With the possibility of this drug acting directly on the thymus, before the installation of diabetes, we investigated this organ in BALB/C mice treated with alloxan (60mg/kg) at the following times: 3, 6, 12 and 24 h. The drug did not show significant effects in these periods on thymus weight, celulalirity, viability of thymocytes and thymus architecture, as well as the percentual of peripheral T-lymphocytes when compared to values of control group. Nonetheless, to analyze the functional aspect of thymus on diabetes condition, we weighed the organ, observed thymus reticulin and architecture in diabetic mice induced by alloxan at 6, 24, 48 hours and 7 days (48 h p.i.). After 6 h, we observed a marked decrease of relative thymus weight, a great loss of cortico-medullary definition and disorganization of extracellular matrix. However, a gradual recovery of these parameters was observed along the experimental times with a total recovery on the 7 th day. Our results suggest that alloxan-induced diabetic experimental model is an option for studies that involve thymus in this pathophysiology, since there is no detrimental effect of this drug on the thymus. Moreover, we suggest that thymus alterations observed in the initial times are consequence of diabetes condition and could be considered as immunological complications with possible impairment in infectious course of these patients.