Molecular biological studies of neurons in the central nervous system relating to the recovery from micturition disorders in rats with central nervous damage

1.在胸髓损伤（TCI）大鼠上观察了鞘内注射肾上腺素能α1A受体拮抗剂坦索罗辛（tamsulosin）和肾上腺素能α1D受体拮抗剂萘哌地尔（naftopidil）对等容膀胱测压的影响。鞘内注射萘哌地尔可使TCI大鼠膀胱收缩短暂停止，并使大剂量萘哌地尔引起的膀胱收缩幅度降低。腰骶髓肾上腺素能α1D mRNA的表达量在TCI后无明显变化。因此，肾上腺素能α1D受体位于排尿反射通路的传入支和传出支，血清中的儿茶酚胺也可能作用于脊髓，促进排尿反射.膀胱测压和尿道外括约肌肌电图检查TCI猫与或没有自体移植肾上腺髓质到骶髓。在自体移植的猫，逼尿肌括约肌协同失调在膀胱收缩改善，酪氨酸羟化酶免疫反应细胞被确认在骶髓。因此，投射到骶髓的儿茶酚胺可使尿道松弛.在大鼠脑梗死（CI）前后进行等容膀胱测压，并测定中枢神经系统谷氨酸和甘氨酸水平。CI后1-7天膀胱收缩频率增加，2-8周恢复到对照组水平。脑梗死后大脑谷氨酸水平降低，脑干、颈胸髓和腰骶髓甘氨酸水平降低。而腰骶髓甘氨酸水平在脑梗死后4-8周恢复至对照水平。因此，膀胱收缩的频率可能取决于腰骶髓中甘氨酸的水平。

1. Effects of intrathecal injections of tamsulosin (adrenergic α1A receptor antagonist) and naftopidil (adrenergicα1D receptor antagonist), on isovolumetric cystometry were investigated in rats with or without thoracic cord injury (TCI). Intrathecal injection of naftopidil transiently stopped bladder contraction, and decreased the amplitude of bladder contractions when large dose of naftopidil was administrated in rats with or without TCI. The volume of mRNA of adrenergic α1D in the lumbosacral cord did not change even after TCI. Therefore, adrenergic α1D receptors were located in both afferent and efferent limbs of the micturition reflex pathway, and serum catecholamines may also act on the spinal cord and facilitate micturition reflex.2. Cystometry and electrical myography of the external urethral sphincter were examined in TCI cats with or without autograft of the adrenal medulla into the sacral cord. In autografted cats, detrusorsphincter dyssynergia during bladder contraction improved, and tyrosine hydroxylase immuno-reactive cells were recognized in the sacral cord. Therefore, catecholamines projecting to the sacral cord may relax the urethra.3. Isovolumetric cystometry was performed before and after cerebral infarction (CI) in rats, and glutamate and glycine levels in the central nervous system were also measured. The frequency of bladder contractions increased 1-7 days after CI, but it returned to the control level 2-8 weeks after CI. Glutamate level in the cerebrum decreased, and glycine levels in the brainstem, cervicothoracic cord, and lumbosacral cord decreased after CI. However, glycine level in the lumbosacral cord returned to the control level 4-8 weeks after CI. Therefore, the frequency of bladder contractions may be depended on the glycine level in the lumbosacral cord.