초산납이 흰쥐 synaptosome의 [3H]-serotonin의 흡수에 미치는 영향

Abstract

Synaptosome에 의한 [^3H]-serotonin의 일반적인 흡수특성과 이 과정에 납이 미치는 영향을 in vitro와 in vivo에서 관찰하였다. 흰쥐의 대뇌와 뇌간에서 각각 분리한 synaptosome의 흡수친화력은 대뇌가 Km=0.5μM, 뇌간이 Km=0.1μM로 모두 고친화성 흡수였고 뇌간에서 더 높았다. 또한 이 흡수과정에 sodium과 potassium 이온이 영향을 미치는 것으로 나타났다. Synaptosome이 [^3H]-serotonin을 흡수하는 과정은 납에 의해 억제되었고 이러한 납의 독성영향은 in vitro와 in vivo에서 유사한 결과를 보였다.

This study was carried out to investigate the physiological changes induced acutely with the low doses of lead acetate in the synaptosomes from the cerebrum and brain stem of the rat. The general uptake patterns of [^3H]-serotonin were observed in synaptosomes, as a model of presynaptic nerve terminal, from the cerebrum and brain stem. And the effects of the low doses of lead acetate on the uptake process were investigated in vitro and in vivo. The Km value of the uptake of the [^3H]-serotonin by the synaptosomes was 0.5μM in the cerebrum and 0.1μM in the brain stem. These low values reveal that the synaptosomes from the cerebrum and the brain stem have a high affinity to [^3H]-serotonin, especially in brain stem. The uptake of [^3H]-serotonin was dependant on the sodium and potassium ions. When being treated with ouabain, the Na^+-K^+ ATPase inhibitor, the uptake of [^3H]-serotonin was reduced. This supports strongly that the uptake of [^3H]-serotonin was sensitive to the changes of the concentrations of the sodium and potassium ions. When the calcium channel blocker, verapamil, was treated, the uptake of [^3H]-serotonin was changed only in synaptosomes from the brain stem. The uptake of [^3H]-serotonin was reduced by the lead treatment in the synaptosomes from the cerebrum and brain stem in vitro and in vivo. [lead acetate, synaptosomes, [^3H]-serotonin, rat]