Participation of Endogenous Opioid Peptide in Sudden Death

采用放射线免疫测定法测定垂体免疫反应性β -内啡肽（ir - β - ep）水平的变化和痛苦期循环ir - β - ep水平的变化，研究雄性和雌性Wistar大鼠对分别由静脉给药KCl和SCC引起的心脏和呼吸衰竭型（CFT和RFT）猝死的垂体反应。CFT和RFT的脏器体重比（CFT>RFT）在两性垂体中差异显著，RFT组ir - β - ep显著低于CFT组（P < 0.05）。CFT患者短时间疼痛时血浆ir - β - ep无变化，而RFT患者长时间疼痛时血浆ir - β - ep显著升高。SCC给药后2或4分钟的最高升高约为给药前男性ir - β - ep的3倍（p0.01）。但女性的升高幅度低于男性。RFT疼痛时血浆ir - β - ep升高被认为是由于地塞米松治疗所致。因此，垂体对RFT的致命痛苦的反应比CFT更大。我们尝试用同一品系的大鼠来确定-内啡肽（- ep）对呼吸系统和心血管系统的影响的性别差异。正常雌雄大鼠经脑室注射β - ep （0.18 mg/kg）后，呼吸频率（RR）、心率（HR）和平均动脉血压（MABP）均显著降低（P < 0.01或0.001），呼气中CO_2含量显著升高（P < 0.01）。静脉注射纳洛酮（0.2 mg/kg）可暂时阻断该肽的这些抑制作用。雌性大鼠发情期与发情期β - ep的作用无明显差异。该肽对女性的RR、HR和MABP的影响明显强于男性（0.001 p0.05）。切除睾丸的大鼠与未切除睾丸的雌性大鼠表现出相同程度的抑制作用，但过度切除睾丸的大鼠与未切除睾丸的雌性大鼠的抑制作用没有差异。在睾丸切除和卵巢切除的大鼠中，用睾酮治疗，前者显示出与完整雄鼠相同的结果，而后者则不然。β - ep对雄性大鼠呼吸系统和心血管系统的抑制作用因此被雄激素显著缓解。少

Using male and female Wistar rats, pituitary response to cardiac and respiratory failure type (CFT and RFT) sudden death caused by the intravenous administration of KCl and SCC, respectively, was examined by analyzing variation in pituitary immunoreactive beta-endorphin (IR-beta-EP) levels determined by radioimmunoassay after death and in circulating IR-beta-EP levels during periods of agony. In the pituitary gland of both sexes which differed significantly in ratio of the organ weight to body weight for CFT and RFT (CFT>RFT), IR-beta-EP was significantly less in RFT than in CFT (P 0.05). No variation in plasma IR-beta-EP was noted during short periods of agony in CFT, but it markedly increased during long periods of agony in RFT. The highest elevation at 2 or 4 minutes after SCC administration was about 3 times the preadministration value for IR-beta-EP in males (P 0.01). But elevation in females was lower than in males. Rise in plasma IR-beta-EP during agony of RFT is regarded to be … More of pituitaryorigin due to dexamethasone treatment. The pituitary was thus concluded to respond more to the fatal agony in RFT than in CFT.An attempt was made to determine sex differences in the effects of beta-endorphin ( beta-EP) on respiratory and cardiovascular systems using the same strain rats. By the intracerebroventicular administration of beta-EP (0.18 mg/kg) to normal male and female rats, respiratory rate (RR), heart rate (HR) and mean arterial blood pressure (MABP) were depressed significantly (P 0.01 or 0.001) and CO_2 in expired gas increased significantly (P 0.01). These suppressive effects of the peptide were transiently blocked by the intravenous injection of naloxone (0.2 mg/kg). No differences in the effects of beta-EP between estrous and diestrous female rats could be detected. The effects of the peptide were significantly stronger in RR, HR and MABP for females than for males (0.001 P 0.05). Testectomized rats showed suppressive effects of the peptide to the same extent as intact females, but the effects in overiectomized rats did not differ from those for intact females. In testectomized and ovariectomized rats treated with testosterone, the former showed the same results as intact males, but not the latter. The suppressive effects of beta-EP on the respiratory and cardiovascular systems are thus remarkably relieved by androgen in male rats. Less