Wang X L, Lee T F, Wang L C
Department of Zoology, University of Alberta, Edmonton, Canada.
Brain Res Bull. 1990 Mar;24(3):389-93. doi: 10.1016/0361-9230(90)90094-g.
Previously we have shown that systemic injection of adenosine antagonists can significantly improve cold tolerance in both rats and humans. However, it is not clear whether systemic administration of adenosine antagonist acts peripherally or centrally at the thermoregulatory site. To resolve this, theophylline (nonselective adenosine receptor blocker), cyclopentyltheophylline (selective A1 receptor blocker) or adenosine deaminase (an enzyme which inactivates adenosine by converting it into inosine) was injected directly into preoptic anterior hypothalamus (POAH) of rats and their thermogenic responses assessed. In contrast to that observed after systemic administration, intrahypothalamic injection of either adenosine antagonists or deaminase at various doses failed to elicit any enhancement in heat production beyond that of the controls. These results suggest that the beneficial effect of systemically injected adenosine antagonists in improving cold tolerance is not the result of altering the thermoregulatory functions mediated via the POAH.
此前我们已经表明，全身注射腺苷拮抗剂可显著提高大鼠和人类的耐寒能力。然而，尚不清楚全身给予腺苷拮抗剂是在体温调节部位的外周还是中枢起作用。为了解决这个问题，将茶碱（非选择性腺苷受体阻滞剂）、环戊基茶碱（选择性A1受体阻滞剂）或腺苷脱氨酶（一种通过将腺苷转化为肌苷使其失活的酶）直接注射到大鼠的视前区下丘脑前部（POAH），并评估它们的产热反应。与全身给药后观察到的情况相反，下丘脑内注射不同剂量的腺苷拮抗剂或脱氨酶均未能引起产热比对照组有任何增强。这些结果表明，全身注射腺苷拮抗剂改善耐寒能力的有益作用不是通过改变经POAH介导的体温调节功能而产生的。
