SNAP-25在成年期甲减大鼠海马内表达变化及甲状腺素治疗效应

Thyroid hormone regulates SNAP-25 expression in the adult rat hippocampus

观察成年期甲状腺功能减退症(简称甲减)大鼠海马内突触相关蛋白SNAP-25(synaptosomal associated protein of 25 kD)改变及不同剂量甲状腺素治疗后的恢复状况,探讨甲减脑损伤及恢复可能的分子机制。结果显示,甲减大鼠血清T3、T4水平显著低于正常对照组(P<0.05),背侧海马突触小体内SNAP-25的表达水平显著高于正常对照组(P<0.05);常规剂量替代治疗组大鼠血清T3、T4恢复至正常水平,SNAP-25表达水平与甲减组比较未见明显改变(P>0.05);经大剂量替代治疗后血清T3、T4高于正常;SNAP-25的表达恢复到正常水平(P<0.05)。这些结果提示,成年期甲减大鼠海马内SNAP-25表达增加,甲状腺素治疗能使其恢复,大剂量替代治疗使SNAP-25表达恢复至正常水平。

We determined the expression of SNAP-25 in adult onset hypothyroidism rat hippocampus and studied the effect of levothyroxin treatment on recovery. Our data showed that serum T3, T4 levels in the hypothyroidism group rats were significantly lower than those in control group rats （P 〈 0. 05 ） ; and the level of SNAP-25 protein were significantly increased in the crude synaptosome of dorsal hippocampus compared to the control group （P 〈 0. 05 ）. Under common dosage of L-T4 treatment, the levels of serum T3,T4 returned to the normal, and the level of SNAP-25 protein was ameliorated, but there was no significant alteration compared to the PTU group （P 〉 0. 05 ）. The high dose could restore the increase of SNAP-25 protein to the normal, the levels of serum T3, T4 were higher than that in control group. These results suggested that adult-onset hypothyroidism can increase the expression of SNAP-25 in the dorsal hippocampus, while levothyroxin could reverse this alteration, and high dose is superior to common dose in recovery of SNAP-25 expression.