Effects of black cohosh and estrogen on core body and tail-skin temperatures in ovariectomized rats by telemetric monitoring with dual thermistor probes

<b>Objectives:</b> To investigate the effects of black cohosh and estrogen on the temperature in ovariectomized rats, the core body temperature (CBT) and tail-skin temperature (TST) were simultaneously monitored and the relationship between these two temperatures was explored. <b>Methods:</b> Twenty-four female Sprague–Dawley rats aged 8 weeks were randomly divided into four groups: sham-operated (SHAM), ovariectomized (OVX), OVX treated with estradiol valerate (OVX + E), and OVX treated with isopropanolic black cohosh extract (OVX + ICR). Rats were sham-operated or ovariectomized and were implanted with telemetry transmitters with dual thermistor probes. Two weeks after surgery, the animals were treated with drugs for 4 weeks. During the last week of the treatments, the dynamic temperature profiles of the CBT and TST were collected. <b>Results:</b> The average CBT and TST, TST fluctuation frequency, and the average amplitude fluctuation were significantly higher in OVX than in SHAM rats. In addition, dramatic fluctuations of TST in OVX rats occurred at the time points of the day when the CBTs were lower in OVX rats than in SHAM rats. Treatment of OVX rats with estradiol valerate or isopropanolic black cohosh extract markedly decreased the average CBT and TST, TST fluctuation frequency, and the average amplitude fluctuation. Moreover, CBT was found to be significantly higher, while TST was lower in OVX + E than in OVX + ICR rats. <b>Conclusions:</b> Both black cohosh and estradiol treatments ameliorated the abnormal thermoregulation in OVX rats. In particular, black cohosh reduced CBT better than estradiol and estradiol reduced TST better than black cohosh.

**研究目的：** 探讨黑升麻（black cohosh）与雌激素对去卵巢大鼠（ovariectomized rats）体温的影响，本研究同步监测其核心体温（core body temperature, CBT）与尾部皮肤温度（tail-skin temperature, TST），并探索两种温度间的关联。
**研究方法：** 选取24只8周龄雌性斯普拉格-道利（Sprague-Dawley, SD）大鼠，随机分为4组：假手术组（sham-operated, SHAM）、去卵巢组（ovariectomized, OVX）、戊酸雌二醇（estradiol valerate）干预去卵巢组（OVX+E）以及异丙醇提取物黑升麻（isopropanolic black cohosh extract）干预去卵巢组（OVX+ICR）。所有大鼠均接受假手术或去卵巢手术，并植入带有双热敏电阻探头的遥测发射器。术后两周，对各组大鼠进行为期4周的药物干预。干预最后一周，采集核心体温与尾部皮肤温度的动态变化图谱。
**研究结果：** 去卵巢组大鼠的平均核心体温、平均尾部皮肤温度、尾部皮肤温度波动频率及平均波动幅度均显著高于假手术组。此外，当日间去卵巢组大鼠的核心体温低于假手术组时，其尾部皮肤温度出现显著波动。对去卵巢大鼠施以戊酸雌二醇或异丙醇提取物黑升麻干预，均可显著降低其平均核心体温、平均尾部皮肤温度、尾部皮肤温度波动频率及平均波动幅度。进一步对比发现，戊酸雌二醇干预组（OVX+E）的核心体温显著高于黑升麻干预组（OVX+ICR），而尾部皮肤温度则更低。
**研究结论：** 黑升麻与雌激素干预均可改善去卵巢大鼠的体温调节异常。具体而言，黑升麻在降低核心体温方面效果优于雌激素，而雌激素在降低尾部皮肤温度方面效果优于黑升麻。