Thyroidectomy induces pancreatic
edema and immune cells infiltration similarly to that observed in
pancreatitis. In spite of the controverted effects of
hypothyroidism on serum
glucose and
insulin concentrations, the number and proliferation of Langerhans islet cells as well as the presence of extracellular matrix are affected depending on the islet size. In this study, we evaluated the effect of
methimazole-induced
hypothyroidism on the vascularization and immune cells infiltration into islets. A general observation of pancreas was also done. Twelve Chinchilla-breed female adult rabbits were divided into control (n = 6) and hypothyroid groups (n = 6,
methimazole, 0.02% in
drinking water for 30 days). After the treatment, rabbits were sacrificed and their pancreas was excised, histologically processed, and stained with
Periodic Acid-Schiff (PAS) or Masson's Trichrome techniques. Islets were arbitrarily classified into large, medium, and small ones. The external and internal portions of each islet were also identified. Student-t-test and Mann-Whitney-U test or two-way ANOVAs were used to compare variables between groups. In comparison with control rabbits,
hypothyroidism induced a strong infiltration of immune cells and a major presence of
collagen and
proteoglycans in the interlobular septa. Large islets showed a high vascularization and immune cells infiltration. The present results show that
hypothyroidism induces
pancreatitis and insulitis.