The experimental study about the effects of psychotropic drugs on the mechanism of water intoxication

精神分裂症患者水中毒以病理性多饮为特征，可引起意识障碍、抽搐等严重症状。抗精神病药物的治疗被认为是这种疾病的原因之一。虽然已经提出了几种导致水中毒发生的机制，但这些机制仍然不清楚。在这项研究中，我们致力于研究氟哌啶醇癸酸酯(HalomonthR；10，20 mg/kg，I.M.)慢性治疗(8周)的效果。高渗刺激大鼠视上核(SON)对精氨酸加压素(AVP)释放和行为学改变(摄水和行走)的影响1)高渗刺激后30-60min(第三期)，摄水发生率主要发生在高渗刺激后30-60min。2)高渗刺激后30-90分钟，SON内AVP水平升高；3)氟哌啶醇处理组动物纹状体内多巴胺水平低于对照组。上述结果提示，慢性氟哌啶醇对SON大鼠摄水量和AVP水平的影响可能与AVP与多巴胺能系统的相互作用有关。

Water intoxication in Schizoprenic patient is characterized by morbid polydipsia and induces severe symptoms such as conscious disturbance and convulsions. And treatment with antipsychotics has been speculated as one of the causal factors in this disorder. Although several mechanisms responsible for development of water intoxication have been proposed, they are still unclear. In this study, we have undertaken to investigate the effect of chronic treatment (8 weeks) with haloperidol decanoate(HalomonthR ; 10, 20 mg/kg, i.m.) on arginine vasopressin (AVP) release and behavioral changes (water-intake and ambulation) by hyperosmotic stimulation of the supraoptic nucleus (SON) in rats.1) The incidence of water-intake mainly produced 30-60 min (third period) after hyperosmotic stimulation. In particular, there was a marked increase in the incidence and volume of water-intake in haloperidol treated animals.2) AVP levels were increased 30-90 min after hyperosmotic stimulation in the same animals.3) Dopamine levels in striatum in haloperidol treated animals were smaller than those in the control.We demonstrated that chronic treatment with haloperidol decanoate enhanced hyperosmotic stimulation-induced water-intake and release of AVP in SON. These results suggest that the increasing effect of water-intake and AVP levels caused by chronic haloperidol treatment may connect with interaction between AVP and dopaminergic system in SON.