家兔电刺激反应性及体温的昼夜变化

Circadian Changes of the Response to Electrical Stimulus and the Body Temperature in Rabbits

一天中１２个等分时间点电刺激家兔（ｎ＝６）后腿肌肉，记录家兔发生抽动反应的阈电压，该阈电压经余弦法分析呈显著余弦振荡（ｐ＜０．０５），其中值Ｍ为１５．７９Ｖ，振幅Ａ为０．４４Ｖ，峰值位相时Φ为－２８２．８８°（时间１８５１）．因此家兔对电刺激的反应性呈明显余弦昼夜节律性变化，下午１８５１反应性最低，上午０６５１反应性最高．室温下测定家兔（ｎ＝９）直肠温度，其变化在３９．５０～４０．０７℃，未呈余弦规律，但仍有节律性变化：最高体温在夜间０２３０，最低体温在下午１６３０。

Electrical stimuli were given in hind leg muscle of six New Zealand rabbits at tewelve equinoxes of a day, and the threshold voltage of the muscle contraction was recorded. These threshold voltages, analyzed by cosinor method, showed a significant cosinor oscillation ( p <0.05)with parameters∶ M (mesor),15.79V; A (amplatude),0.44V;and Φ (acrophase)-282.88 degrees(time:18:51). In other words, the response to electrical stimulus in rabbits displayed circadian cosinor rhythm with the peak at 06:51 am,and the nadir at 18:51 pm. The rectal temperature was measured in another nine rabbits raised in a room without temperature control. The body temperature varied from 39.50 to 40.07℃,did not show cosinor change ( p >0.05). However, the body temperature still showed a rhythm with the peak at 02:30, the nadir at 16:30 and a maintenance of higher body temperature from 00:30 to 14:30.