Involvement of purinergic signalling in central mechanisms of body temperature regulation in rats
作者:Alexander V Gourine、Ekaterina V Melenchuk、Dmitry M Poputnikov、Valery N Gourine、K Michael Spyer
DOI:10.1038/sj.bjp.0704679
日期:2002.4
P2 purinoreceptors are present in hypothalamic and brainstem nuclei that are involved in the regulation of body temperature (Tb). The role of ATP acting on these P2 receptors in thermoregulation was investigated by studying the effects of the stable ATP analogue α,β‐methyleneATP (α,β‐meATP) and P2 receptor antagonists suramin and pyridoxal‐5′‐phosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS) on Tb when injected intracerebroventricularly (i.c.v.) via a pre‐implanted cannula in conscious rats at various ambient temperatures and during lipopolysaccharide (LPS)‐induced fever.
Depending on ambient temperature, α,β‐meATP (0.2 μmol, i.c.v.) induced a fall in Tb (−3.3°C, P<0.05), no changes in Tb when compared to pre‐injection levels, or an increase in Tb (∼1.0°C, P<0.05) in rats maintained at 10°C, 25°C and 30°C ambient temperature, respectively.
Suramin (7 nmol, i.c.v.) induced a lasting (up to 6 h) increase in Tb (on average 1.2°C, P<0.05) in rats kept at 25°C or 30°C, but failed to induce any rise in Tb in rats at 10°C ambient temperature. An increase in Tb was also observed in rats (25°C ambient temperature) treated with PPADS (0.2 μmol, i.c.v.).
α,β‐meATP (0.2 μmol) injected i.c.v. or directly into the anterior hypothalamus caused a profound fall in Tb (by 0.9°C and 1.0°C, respectively; P<0.05) during LPS (E.coli; 50 μg kg−1)‐induced fever in rats at 25°C ambient temperature. Fever was initiated more rapidly in rats treated with suramin (7 nmol) or PPADS (70 nmol), however its late phase was unaffected. Suramin (7 nmol) and PPADS (70 nmol) injected at the time when fever was already developed (2.5 h after LPS injections) did not alter febrile Tb.
These data indicate that purinergic signalling may play a significant role in central mechanisms of Tb regulation at various ambient temperatures and during fever.
British Journal of Pharmacology (2002) 135, 2047–2055; doi:10.1038/sj.bjp.0704679
在下丘脑和脑干核中存在P2嘌呤受体,这些核团参与了体内温度调节(Tb)。研究了ATP作用于这些P2受体在体温调节中的作用,方法是通过预先植入的导管将稳定的ATP类似物α,β-甲基ATP(α,β-meATP)和P2受体拮抗剂suramin及吡哆醛-5′-磷酸-6-偶氮苯基-2′,4′-二磺酸(PPADS)直接注入清醒大鼠脑室内(i.c.v.),在不同环境温度下及脂多糖(LPS)诱导的发热过程中观察其对Tb的影响。根据环境温度的不同,α,β-meATP(0.2 μmol,i.c.v.)在分别维持在10°C、25°C和30°C环境温度的大鼠中,诱导Tb下降(-3.3°C,P < 0.05),或与注射前水平无变化,或Tb升高(约1.0°C,P < 0.05)。suramin(7 nmol,i.c.v.)在25°C或30°C环境下使Tb持续升高(平均升高1.2°C,P < 0.05),时间长达6小时;但在10°C环境温度下未能引起Tb升高。在25°C环境温度下PPADS(0.2 μmol,i.c.v.)处理的大鼠中也观察到了Tb升高。α,β-meATP(0.2 μmol)在i.c.v.或直接注入前下丘脑时,在25°C环境温度下E. coli(50 μg kg−1)诱导的发热大鼠模型中,引起明显的Tb下降(分别为0.9°C和1.0°C,P < 0.05)。接受suramin(7 nmol)或PPADS(70 nmol)处理的动物,发热启动更快,但其发热的后期阶段不受影响。当在发热已经发生(LPS注射后2.5小时)时给予suramin(7 nmol)或PPADS(70 nmol),则未改变发热状态下的Tb。这些数据表明,嘌呤信号传递可能在各种环境温度下及发热过程中的体温调节中枢机制中发挥重要作用。英国药理学杂志 (2002) 135, 2047–2055; doi:10.1038/sj.bjp.0704679