Petersson M, Ahlenius S, Wiberg U, Alster P, Uvnäs-Moberg K
Department of Molecular Medicine, Karolinska Hospital, Stockholm, Sweden.
Brain Res Bull. 1998;45(3):301-5. doi: 10.1016/s0361-9230(97)00372-9.
In the present study, dose relationships for effects of oxytocin (OXY) on spontaneous motor activity in female rats were investigated. Ovariectomized (OVX) and cycling female Sprague-Dawley rats were given OXY 10-1000 microg/kg s.c. or saline, 10 min before registration of motor activity in an open-field arena. In the OVX rats, 100 microg/kg of OXY increased the activity in the center of the arena, whereas 1000 microg/kg decreased locomotor activity (LA). In the cycling rats, OXY 100-1000 microg/kg decreased LA during diestrus, while 1000 microg/kg also decreased LA during metestrus. The latter dose also reduced the exploratory behavior during estrus. In a second experiment, OVX rats were pretreated with estradiol benzoate (EB) and progesterone (P). When P levels were predominant, OXY 10-1000 microg/kg decreased LA. Oxytocin 10-100 microg/kg given after pretreatment with EB increased the activity in the center of the arena, whereas 1000 micro/kg given in the presence of both EB and P increased peripheral activity (PA). These results show that the effects of OXY on motor activity in female rats are modified by female sex steroid hormones.
在本研究中，研究了催产素（OXY）对雌性大鼠自发运动活动影响的剂量关系。在开放场地记录运动活动前10分钟，给去卵巢（OVX）和处于发情周期的雌性Sprague-Dawley大鼠皮下注射10 - 1000微克/千克的OXY或生理盐水。在OVX大鼠中，100微克/千克的OXY增加了场地中央的活动，而1000微克/千克则降低了运动活动（LA）。在处于发情周期的大鼠中，100 - 1000微克/千克的OXY在间情期降低了LA，而1000微克/千克在动情后期也降低了LA。后一剂量在发情期也减少了探索行为。在第二个实验中，给OVX大鼠预先注射苯甲酸雌二醇（EB）和孕酮（P）。当P水平占主导时，10 - 1000微克/千克的OXY降低了LA。用EB预处理后给予10 - 100微克/千克的催产素增加了场地中央的活动，而在同时存在EB和P的情况下给予1000微克/千克则增加了外周活动（PA）。这些结果表明，雌性大鼠中OXY对运动活动的影响受到雌性性激素的调节。
