强啡肽A_(1～13)对大鼠脑出血后脑水肿的治疗作用

Dynorphin A 1￣13 can reduced brain edema following collagenase induced intracerebral hemorrhage in rats

目的研究强啡肽Ａ（ＤｙｎＡ１～１３）与大鼠胶原酶诱导的脑出血后脑水肿形成的关系，寻找治疗脑出血后脑水肿的特异性药物。方法大鼠大脑尾壳核内微量注射０．４ＩＵ细菌胶原酶；４ｈ后侧脑室注射ＤｙｎＡ１～１３及κ受体拮抗剂ｎｏｒ－ＢＮＩ；放射免疫法测定脑出血大鼠皮层、海马、尾壳核、下丘脑和垂体中ＤｙｎＡ１～１３含量；干湿重法测定脑组织含水量。结果胶原酶诱导大鼠脑出血后，顶叶皮层、额叶皮层、海马和尾壳核内ＤｙｎＡ１～１３含量明显减少，与对照组相比，Ｐ＜０．０５，Ｐ＜０．０１，与此同时，上述脑区组织含水量亦明显增加；但下丘脑和垂体ＤｙｎＡ１～１３含量明显增加（Ｐ＜０．０１）。侧脑室给予ＤｙｎＡ１－１３可以显著降低脑出血后脑组织含水量；κ受体拮抗剂ｎｏｒ－ＢＮＩ可以阻断该作用。结论ＤｙｎＡ１～１３可以通过κ受体治疗脑出血后脑水肿。

AIM To study the ralation between dynorphin A 1￣13 (DynA 1￣13 ) and brain edema after intracerebral hemorrhage in rats and to find a medicine which can decrease brain edema. METHODS 0 4 unit bacterial collagenase was injected into the adult rats left caudate nucleus 4 h before intracerebroventricular (ICV) administration of κ receptor antagonist nor BNI or DynA 1￣13 . Dyn A 1￣13 contents in cortex, hippocampus, caudoputamen, hypothalamus and pituitary were detected by radioimmunoassay. Water content expressed as the percentage change between the dry and the wet weight of brain. RESULTS After collagenase induced intracerebral hemorrhage, the contents of DynA 1￣13 were decreased significantly in frontal cortex, parietal cortex, hippocampus and caudoputamen in rats ( P <0 05, P <0 01) as compared with the controls, accompanied by brain water contents increase, but the contents of DynA 1￣13 were increased in pituitary and hypothalamus ( P <0 01). ICV administration of DynA 1￣13 significantly reduced water contents of brain area in the intracerebral hemorrhagic rats ( P <0 01), and κ receptor antagonist nor BNI can block this effect. CONCLUSIONS DynA 1￣13 may reduce brain edema follwing intracerebral hemorrhage in rats, which is possibly mediated by κ receptor.