Terasawa E, Goldfoot D A, Davis G A
Brain Res. 1976 May 7;107(2):375-83. doi: 10.1016/0006-8993(76)90234-1.
Administration of pentobarbital inhibits the facilitatory effects of progesterone on the release of gonadotropins. In this experiment facilitatory effects of progesterone on lordosis behavior in guinea pigs were examined with pentobarbital anesthesia. Two major animal groups were subjects: one was short-term ovariectomized (2 weeks) and the other was long-term ovariectomized (several months). All animals received estradiol benzoate (6.6 mug s.c.) followed by progesterone (0.4 mg s.c.) 40 h later. Lordosis behavior was induced by the manual stimulation method of Young et al.29 Sodium pentobarbital (30 mg/kg) was injected 8,4 or 2 h before, simultaneously or 1, 2, 6, or 7 h after progesterone. Animals which received pentobarbital slept for 4.5-5 h with subsequent drowsiness for an additional 0.5-1 h. Pentobarbital injections given 8 h before progesterone had no effect on latency to the first lordosis or on other parameters of estrous behavior. However, pentobarbital delayed the onset of heat in estrogen treated ovariectomized guinea pigs when given 4 h before, 2 h before, or simultaneously with progesterone. The delay was directly related to the length of time the animals remained asleep after the progesterone injection, since estrous behavior was invariably displayed with the latency of controls after the animal awoke. Moreover, in animals which were awake for 1-2 h immediately after the progesterone injection before receiving pentobarbital, the latency of recovery from anesthesia to the first display of lordosis was about 1-1.5 h shorter than in the other pentobarbital groups. In contrast to the latency effects of pentobarbital, the duration of heat was unaffected by the anesthetic for all groups mentioned. In animals which received pentobarbital after they were already in heat, pentobarbital injection terminated heat and abolished it completely, since lordosis behavior was not displayed in the hours after recovery from anesthesia. Gross hypothalamic uptake of progesterone was not influenced by pentobarbital administration. Thus, it is tentatively concluded that an incubation period is necessary for progesterone to mediate the display of estrous behavior in the guinea pig in addition to the time necessary for neural uptake. The way in which pentobarbital interferes with the period of progesterone incubation is not currently known.
戊巴比妥的给药会抑制孕酮对促性腺激素释放的促进作用。在本实验中，在戊巴比妥麻醉下检测了孕酮对豚鼠脊柱前凸行为的促进作用。主要有两个动物组作为研究对象：一组是短期卵巢切除（2周）的，另一组是长期卵巢切除（数月）的。所有动物均皮下注射苯甲酸雌二醇（6.6微克），40小时后再皮下注射孕酮（0.4毫克）。采用Young等人的手动刺激方法诱导脊柱前凸行为。在注射孕酮前8小时、4小时或2小时、同时或注射孕酮后1小时、2小时、6小时或7小时注射戊巴比妥钠（30毫克/千克）。接受戊巴比妥的动物睡4.5 - 5小时，随后还会有0.5 - 1小时的嗜睡。在注射孕酮前8小时注射戊巴比妥对首次脊柱前凸的潜伏期或发情行为的其他参数没有影响。然而，在注射孕酮前4小时、2小时或同时注射戊巴比妥时，戊巴比妥会延迟雌激素处理的卵巢切除豚鼠的发情开始时间。这种延迟与动物在注射孕酮后睡眠的时间长短直接相关，因为发情行为总是在动物醒来后与对照组的潜伏期一样表现出来。此外，在注射孕酮后立即清醒1 - 2小时然后接受戊巴比妥的动物中，从麻醉恢复到首次表现出脊柱前凸的潜伏期比其他戊巴比妥组短约1 - 1.5小时。与戊巴比妥对潜伏期的影响相反，所有上述组的发情持续时间不受麻醉剂影响。在已经发情的动物中注射戊巴比妥，戊巴比妥注射会终止发情并完全消除它，因为在从麻醉恢复后的数小时内没有表现出脊柱前凸行为。戊巴比妥的给药对下丘脑对孕酮的总体摄取没有影响。因此，初步得出结论，除了神经摄取所需的时间外，孕酮介导豚鼠发情行为的表现还需要一个潜伏期。目前尚不清楚戊巴比妥干扰孕酮潜伏期的方式。
