Summerlee A J, Ramsey D G, Poterski R S
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Canada.
Endocrinology. 1998 Feb;139(2):479-84. doi: 10.1210/endo.139.2.5741.
Experiments were performed to determine whether neutralization of relaxin in the brain, by injecting monoclonal antibodies to rat relaxin into the ventricular system of the brain, affected either the timing or the processes of birth in rats. Pregnant rats were injected daily through a chronically implanted intracerebroventricular cannula either with a specific monoclonal antibody raised against rat relaxin from days 12-22 of gestation or with an antibody raised against fluorescein as a control. The rats were watched closely from the afternoon of day 20 of pregnancy, and the process of birth was observed. No sign of dystocia was observed in any of the rats in the experiment. Neutralization of endogenous relaxin caused a significant decrease in the length of gestation (505.4 +/- 3.1 h) compared with that in rats treated with PBS (524.6 +/- 0.5 h) or that in rats treated with a nonspecific antibody (525.9 +/- 0.7 h). The time to the onset of delivery was also shorter in the relaxin-neutralized group (507.8 +/- 1.1 h) compared with that in either PBS-treated (526.5 +/- 0.6 h) or fluorescein antibody-treated (525.3 +/- 0.7 h) animals. In contrast, there was no significant effect of the relaxin antibody on length of straining, duration of parturition, delivery interval, live birth rate, or body weight of the neonates. Premature delivery in the relaxin-neutralized group was accompanied by a 24-h advance in the fall in plasma progesterone. These data support the hypothesis that there may be a central relaxin system that is independent of the peripheral relaxin system. Central relaxin may have a significant physiological role on the timing of pregnancy in the rat, but does not affect the course of labor once it has started.
进行实验以确定通过向大鼠脑室内系统注射抗大鼠松弛素单克隆抗体来中和脑中的松弛素是否会影响大鼠的分娩时间或过程。妊娠大鼠从妊娠第12天至22天通过长期植入的脑室内插管每天注射一种针对大鼠松弛素产生的特异性单克隆抗体，或注射一种针对荧光素产生的抗体作为对照。从妊娠第20天下午开始密切观察大鼠，并观察分娩过程。实验中任何大鼠均未观察到难产迹象。与用PBS处理的大鼠（524.6±0.5小时）或用非特异性抗体处理的大鼠（525.9±0.7小时）相比，内源性松弛素的中和导致妊娠期显著缩短（505.4±3.1小时）。与用PBS处理的动物（526.5±0.6小时）或荧光素抗体处理的动物（525.3±0.7小时）相比，松弛素中和组开始分娩的时间也更短（507.8±1.1小时）。相比之下，松弛素抗体对产程、分娩持续时间、分娩间隔、活产率或新生儿体重没有显著影响。松弛素中和组的早产伴随着血浆孕酮下降提前24小时。这些数据支持这样的假设，即可能存在一个独立于外周松弛素系统的中枢松弛素系统。中枢松弛素可能对大鼠的妊娠时间有重要的生理作用，但一旦分娩开始，并不影响分娩过程。
