Pathological characteristics of renal damage in rats with hypothyroidism caused by iodine deficiency / 中华内分泌代谢杂志

ABSTRACT

Objective To study the renal pathology and expression of vascular endothelial growth factor (VEGF) in rats with hypothyroidism caused by iodine deficiency.Methods The rats were randomly grouped into test group and normal group,and the test group was further randomly divided into model group and L-T4 group.Observation were made when the hypothyroid model was formed after maneuvering for 21 days and the medication had been taken for 56 days.The observed data included the morphogy of the kidney,serum TT3,TT4,TSH,blood urea nitrogen (BUN),serum creatinine (SCr),and VEGF expression.Results (1) After medication for 56 days,compared to normal group,BUN and SCr levels in L-T4 and model groups showed apparently increasing [BUN (5.55 ± 0.50,5.80 ± 0.66 vs 5.00 ± 0.24) mmol/L,P＜0.05 ; SCr (26.83 ± 0.75,27.0 ± 3.41 vs 22.5 ± 2.07) μmol/L,P＜0.05],and L-T4 group showed slightly lowered BUN and SCr levels compared with model group (P＞0.05).(2) By 21 days,in the model group there was moderate mesangial hyperplasia involving focal glomeruli.By 56th day of medication,entire glomeruli showed moderate mesangial hyperplasia with lessened number of dilated capillaries in the model group.However,in the L-T4 treated group,mesangial hyperplasia was much less and capillaries though dilated appeared wholesome,as compared with the model group.(3) By 21th day,the IODA value of VEGF in the model group was higher than that in the normal control (44.64 ± 14.99 vs 29.05 ± 9.14,P＜0.01).After medication for 56 days,there was no significant difference in the IODA value of three groups.Conclusions The characteristics of renal pathology in rats with hypothyroidism caused by iodine deficiency consist of mesangial hyperplasia and loss of glomerular capillaries.The expression of VEGF is raised early in the course of renal damage,but lowered thereafter.L-T4 can not reverse the sustained kidney damage and impaired renal function.