降低雌激素水平对大鼠降钙素基因相关肽合成与释放的影响

Effects of estrogen decrease on CGRP release in rats

目的 探索女性绝经后雌激素水平降低对降钙素基因相关肽 (CGRP)的影响。方法 采用大鼠去卵巢模型及苯甲酸雌二醇皮下注射进行替代治疗 ,分别于治疗 1个月、2个月时 ,用CGRP特异性放免分析的方法测定血清、组织 (腹主动脉、十二指肠、背根神经节 )及外周神经刺激 (PNS)后离体肠系膜血管灌流液中的CGRP样免疫活性 (CGRP LI)物质。结果 1个月时 ,非替代治疗组血清、腹主动脉、十二指肠组织中CGRP LI[(2 7 64± 4 63 )pg/μl,(4 12± 1 5 1)pg/μg,(4 67± 0 71)pg/μg]明显高于假手术组 [(15 79± 3 0 2 )pg/μg ,(0 68± 0 2 9)pg/μg,(2 13± 0 3 5 )pg/μg) ,P <0 0 5 ;非替代治疗组肠系膜灌流液基础以及PNS(4Hz、16Hz)引起的CGRP释放 [(7 880± 0 4 49)pg/ml,(16 2 5 0±1 73 4)pg/ml,(19 80 7± 1 62 1)pg/ml)明显高于假手术组 [(5 2 14± 0 914 )pg/ml,(11 2 89± 1 0 3 5 )pg/ml,(13 3 70± 0 60 6)pg/ml],P <0 0 5 ,雌激素替代后恢复至对照水平。 2个月时去卵巢引起的CGRP组织含量和释放的变化均消失。结论 CGRP在绝经后短期内通过合成与释放的增加 ,加强了对心血管系统的保护 ,但这种作用是短暂的。

Objective To study effects of estrogen decrease on release of calcitonin gene related peptide (CGRP). Methods In ovariectomized (OVX) female Wistar rats, hormone estradioli benzoas (40 μg/day) replacement therapy (HRT) was conducted for 2 months. At one month and two months of HRT, CGRP like immunoactivity (CGRP LI) in serum, supernatant of homogenized tissues (abdominal aorta, duodenum, dorsal root ganglion) and perfusated of isolated perfused mesenteric arterial bed stimulated by perivascular nerve stimulation (PNS) (2 Hz, 4 Hz and 16 Hz) was determined by CGRP specific RIA. Results As compared with the sham operated group, CGRP LI of the abdominal artery and duodenum was significantly elevated in the OVX group at one month, the basal and PNS stimulated (4 Hz and 16 Hz) CGRP LI release in the OVX group was also increased. The above changes were restored after HRT. At two months, the OVX related changes of CGRP disappeared. Conclusion CGRP protects the cardiovascular system by increase of CGRP release only shortly after menopuase. However, the effects are transient.