Dynamic changes of tumor necrosis factor-a levels in plasma of renovascniar hypertensive rats and significance of these changes on cerebrovascular disease

Objective To observe the dynamic changes of tumor necrosis factor-a （TNF-a） level in the plasma of renovascular hypertensive rats during the development of hypertension and detemine the possibility of TNF-a as an predictor in the cerebral vessel events. Methods Two-kidney two-clip renovascular hypertension was induced in 45 male SD rats as hypertension （H） group; another 15 rats were employed as sham-operated （SO） group. The systolic blood pressure of preheated conscious rats （37 ℃, 15 minutes） was measured by an indirect tail-cuff sphygrnomanometer. The level of TNF-a in the serum was measured by enzyme-linked immunosorbant assay at pre-operation, and 2, 4, 8, 12, 16 w after the operation. Sixteen w after the operation, 2 ram-thick coronal section of brain tissue were stained with hematoxylin-eosin for routine light microsopic observation. Based on the pathological results of cerebral vessels, the H group was subdivided into isolated hypertension （IH） group and hypertensive cerebral vessels lesion （HCVL） group. Results The postoperative blood pressure （BP） and level of TNF-a in the H group were elevated and time-dependent after the operation with significant differences between any 2 time points （P〈0.05）. The blood pressure and the level of TNF-a in the H group were remarkly higher than those in the SO group at corresponding periods （P〈0.05）. The postoperative BP in the IH group was gradually advanced, while that in the HCVL group kept increasing and significant differences were noted between any 2 time points （P〈0.05）. The level of TNF-a in the HCVL group were increased 2 w after operation and strikingly higher than that in the IH group from 4 to 16 w （P〈0.05）. Conclusions TNF-a, involving in the development of hypertension, may connect to the happening ofatherosclerosis and stroke. Up-regulative level of TNF-a may play a precaution role in the process of stroke in patients with hypertension. Key words: Stroke;  Renovascular hypertension;  Tumor necrosis factor;  Cerebral atherosclerosis