Dési I, Nagymajtényi L, Papp A, Schulz H
Department of Public Health, Albert Szent-Györgyi Univ. Med. School and WHO Collaborating Centre for Chemical Safety, Szeged, Hungary.
Neurotoxicology. 1998 Aug-Oct;19(4-5):611-6.
The neurotoxic effects of Dimethoate (Dim), Dichlorvos (DDVP) and Methyl-Parathion (MP) respectively were investigated on the central nervous system (CNS) and peripheral nervous system (PNS) of rats after different treatment schedules at the macro and single unit cell level. At the macro investigations 1/25, 1/50 and 1/100 of the respective LD50 values of each pesticide were administered to different groups by gavage daily in the following programs: Pregnancy variation (P) to females from 5th to 15th days of pregnancy; Pregnancy and lactation variation (P+L): to females as above and during lactation for 4 weeks; Pregnancy+lactation+post weaning variation (P+L+P) as above plus to the young male rats (F1 generation) up to 8 weeks. Neurotoxicological investigations were conducted on the F1 rats at the age of 12 weeks. Spontaneous electrocorticograms (ECoG) were recorded on the anesthetized rats from the somatosensory, visual and auditory cortex. Cortical evoked potentials (EP) were recorded from the same areas subsequently. Conduction velocity and refractory periods of the tail nerve was investigated. Treatment by Dim, DDVP and MP during P and P+L of the mothers did not influence the bioelectric activity of the offsprings significantly. The same treatment by the P+L+P programme, resulted in significant changes. Frequency of the spontaneous ECoG waves grew significantly in all dose groups of P+L+P group. Latency time become shorter after somatosensory. light or acoustic stimuli respectively on one hand and the beginning of the of answer of these by the evoked potential (EP) waves on the other hand. Conduction velocity of the tail nerve diminished, refractory periods grew dose dependently and significantly at the P+L+P programs with all the three pesticides. Cortical single unit activity was studied after the i.p administration of 1/5 LD50 of the three organophosphates (OP). The decrease of the firing frequencies was observed. The amplitude of the hippocampal population spikes increased. The changes observed in these studies point toward a higher excitation state of the CNS and a disturbed conduction of the nervous impulses of the peripheral nerves. These results could be taken into consideration when deciding on human contaminations by OP-s.
分别研究了乐果（Dim）、敌敌畏（DDVP）和甲基对硫磷（MP）在不同处理方案下，于大鼠宏观和单单位细胞水平对中枢神经系统（CNS）和外周神经系统（PNS）的神经毒性作用。在宏观研究中，按照以下方案，通过灌胃每日将每种农药各自LD50值的1/25、1/50和1/100给予不同组：孕期变化（P）：对妊娠第5至15天的雌性大鼠；孕期和哺乳期变化（P+L）：对上述雌性大鼠以及哺乳期4周；孕期+哺乳期+断奶后变化（P+L+P）：如上述处理雌性大鼠，并对幼龄雄性大鼠（F1代）处理至8周龄。对12周龄的F1大鼠进行神经毒理学研究。在麻醉大鼠的体感、视觉和听觉皮层记录自发脑电图（ECoG）。随后在相同区域记录皮层诱发电位（EP）。研究尾神经的传导速度和不应期。母亲在孕期和孕期+哺乳期接受Dim、DDVP和MP处理对后代的生物电活动无显著影响。通过孕期+哺乳期+断奶后方案进行相同处理则导致显著变化。在孕期+哺乳期+断奶后组的所有剂量组中，自发ECoG波频率显著增加。一方面，体感、光或声刺激后的潜伏期分别缩短，另一方面，诱发电位（EP）波对此类刺激的反应起始时间缩短。在孕期+哺乳期+断奶后方案下，使用这三种农药时，尾神经的传导速度降低，不应期呈剂量依赖性显著延长。腹腔注射三种有机磷酸酯（OP）各自1/5 LD50后，研究皮层单单位活动。观察到放电频率降低。海马群体峰电位的幅度增加。这些研究中观察到的变化表明中枢神经系统处于较高兴奋状态，外周神经的神经冲动传导受到干扰。在确定人类有机磷酸酯污染情况时，可考虑这些结果。
