Changes in extracellular serotonin in rat hypothalamus affect thermoregulatory function
Changes in extracellular serotonin in rat hypothalamus affect thermoregulatory function
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DOI：
10.1152/ajpregu.1998.274.5.r1260
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发表时间：
1998-05-01
影响因子：
2.8
通讯作者：
Chueh, FY
中科院分区：
文献类型：
--
作者：
Lin, MT;Tsay, HJ;Chueh, FY
本实验观察了在非麻醉束缚状态下改变大鼠下丘脑5-羟色胺（5-HT）水平对体温调节功能的影响。用含有5-羟色氨酸（5-HT前体）、氟西汀（5-HT再摄取抑制剂）或高钾的透析液局部灌注下丘脑显著增加结肠温度（T-co）和下丘脑中5-HT的细胞外浓度。相反，在含有河豚毒素（阻断电压依赖性钠通道）的透析液、零钙浓度或全身给予8-羟基-2-（二正丙基氨基）四氢萘（8-OH-DPAT，5-HT 1A激动剂）的情况下，下丘脑和T-co中的细胞外5-HT浓度均降低。下丘脑内注射8-OH-DPAT和（2，5-二甲氧基-4-碘苯基）-2-氨基丙烷（5-HT 2激动剂）分别产生体温降低和体温升高效应。结果表明，升高下丘脑5-HT水平激活突触后5-HT 2受体，导致体温升高效应，而刺激下丘脑突触前5-HT 1A受体减少内源性5-HT释放，导致体温降低效应。
Experiments were carried out to determine the effects of altering the serotonin (5-HT) levels in the hypothalamus on thermoregulatory function in unanesthetized restrained rats. Local perfusion of the hypothalamus with dialysis solution containing 5-hydroxytryptophan (a 5-HT precursor), fluoxetine (a 5-HT reuptake inhibitor), or high potassium significantly increased both colonic temperature (T-co) and the extracellular concentrations of 5-HT in the hypothalamus. Reciprocally, both extracellular concentration of 5-HT in the hypothalamus and T-co were decreased with a dialysis solution containing tetrodotoxin (which blocks the voltage-dependent sodium channel), zero calcium concentration, or systemic administration of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 5-HT1A agonist). Intrahypothalamic administration of 8-OH-DPAT and (2,5-dimethoxy-4-iodophenyl)-2-aminopropane (a 5-HT2 agonist) produced hypothermic and hyperthermic effects, respectively. The results indicate that elevating the 5-HT levels in the hypothalamus activates postsynaptic 5-HT2 receptors and results in hyperthermic effects, whereas stimulation of presynaptic 5-HT1A receptors in the hypothalamus reduces the endogenous 5-HT release and results in hypothermic effects.