Abstract
In an attempt to find out early and sensitive clinical signs of experimental methylmercury poisoning, physiological indices of wakefulness, slow-wave sleep, paradoxical sleep, body temperature and heart rate were examined during the development of methylmercury toxicity with rats which were chronically implanted with EEG and EMG electrodes or thermistor probes and ECG electrodes. These physiological indices were found to provide early and sensitive signs in experimental methylmercury poisoning with adult rats as compared with the behaviorally-observed neurological signs of motor incoordination. The reduction of paradoxical sleep, its altered circadian rhythm and the lowered body temperature were long-lasting signs as compared with quick recovery from the reduced wakefulness and the lowered heart rate. Analysis of brain monoamines and their metabolites showed that the concentrations of noradrenaline, 3-methoxy-4-hydroxyphenylethyleneglycol and 5-hydroxytryptamine of the frontal cortex of the methylmercury-administered rats were lowered during the dark period, indicating that methylmercury lowered the turnover of central monoamine metabolisms. It was suggested that the reduction of paradoxical sleep and its altered circadian rhythm were mediated through an inhibitory action of methylmercury on central monoaminergic mechanisms, in addition to the well-documented inhibitory effect of methylmercury on central cholinergic mechanisms.
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References
Arito, H., Sudo, A., Hara, N., Nakagaki, K. and Torii, S., 1982, Changes in circadian sleep-waking rhythms of rats following administration of methylmercury chloride. Industr. Health, 20: 55.
Arito, H., Hara, N. and Torii, S., 1983, Effect of methylmercury chloride on sleep-waking rhythms in rats. Toxicol., 28: 335.
Arito, H., Oguri, M. and Tanaka, S., 1985, Diurnal variations of brain noradrenaline metabolism of the methylmercury chloride-administered rat with reference to an altered circadian rhythm of paradoxical sleep. Industr. Health, 23: 245.
Arito, H., Tsuruta, H. and Oguri, M., 1988, Changes in sleep and wakefulness following single and repeated exposures to toluene vapor in rats. Arch. Toxicol., 62: 76.
Czeisler, C.A. and Guilleminault, C. (eds.), 1980, A workshop on REM sleep; Its temporal distribution, Sleep, 2:285.
Fehling, C., Abdulla, M., Brun, A., Dictor, M., Schutz, A. and Skerfving, S., 1975, Methylmercury poisoning in the rat: A combined neurological, chemical, and histophathological study, Toxicol. Appl. Pharmacol., 33:27.
Glowinski, J. and Iversen, L.L., 1966, Regional studies of catecholamine in the rat brain. I. The disposition of 3H-norepinephrine, 3H-dopamine and 3H-dopa in various regions of brain, J. Neurochem., 13:655.
Hargreaves, R.J., Foster, J.R., Pelling, D., Moorhouse, S.R., Gangolli, S.D. and Rowland, I.R., 1985, Changes in the distribution of histochemically localized mercury in the CNS and in tissue levels of organic and inorganic mercury during the development of toxication in methylmercury treated rats, Neuropath. Neurobiol., 11:383–401.
Herman, S.P., Klein, R., Talley, F.A. and Krigman, M.R., 1973, An ultrastructural study of methylmercury-induced primary sensory meuropathy in the rat, Lab. Invest., 28:104.
Honma, K., 1985, Circadian rest-activity cycles in rats: Its modulation by humoral factors affecting the central transmitter systems, in: “Endogenous sleep substances and sleep regulation,” S. Inoue and AA. Borbely, Ed., 89–100, Jpn. Sci. Soc. Press, Tokyo.
Klein, R., Herman, S.P., Brubaker, P.E. and Lucier, G.W., 1972, A model of acute methylmercury intoxication in rats. Arch. Path. 93: 408.
Kobayashi, H., Yuyama, A., Matsusaka, N., Takeno, K. and Yanagiya, I., 1980, Effect of methylmercury on brain acetylcholine concentration and turnover in mice. Toxicol. Appl. Pharmacol. 54: 1.
Magos, L and Butler, W.H., 1972, Cumulative effects of methylmercury dicyandiamide given orally to rats. Food Cosmet. Toxicol., 10: 513.
Misumi, J., 1979, Electrophysiological studies in vivo on peripheral nerve function and their application to peripheral neuropathy produced by organic mercury in rats. III Effects of methylmercury chloride on compound action potentials in the sciatic and tail nerve in rats. Kumamoto Med. J. 32: 15.
Miyama, T., Minowa, K., Seki, H., Tamura, Y., Mizoguchi, I., Ohi, G. and Suzuki, T., 1983, Chronological relationship between neurological signs and electrophysiological changes in rats with methylmercury poisoning, special reference to selenium protection. Arch. Toxicol., 52:173.
Moller-Madsen, B., 1990, Localization of mercury in CNS of the rat. II. Intraperitoneal injection of methylmercuric chloride and mercuric chloride. Toxicol. Appl. Pharmacol., 103: 303.
Myers, R.D., 1980, Hypothalamic control of thermoregulation, in: “Handbook of the hypothalamus, behavioral studies of the hypothalamus”, P.J. Morgane and J. Panksepp, eds., 83–210, Marcel Dekker Inc., New York.
Ohi, G., Nishigaki, S., Seki, H., Tamura, Y., Mizoguchi, I., Yagyu, H. and Nagashima, K., 1978, Tail rotation, An early neurological sign of methylmercury poisoning in the rat. Environ. Res., 16:353.
Ornata, S., Horgome, T., Momose, Y., Kambayashi, M., Mochizuki, M. and Sugano, H., 1980, Effect of methylmercury chloride on the in vivo rate of protein synthesis in the brain of the rat: Examination with the injection of a large quantity of (14C)valine. Toxicol. Appl. Pharmacol., 56: 207.
Roussel, B.B. and Bittel, J., 1979, Thermogenesis and thermolysis during sleeping and waking in the rat. Pflugers Arch., 382: 225.
Sakai, K., 1985, Anatomical and physiological basis of paradoxical sleep. In: “Brain mechanism of sleep,” D.J. McGinty, ed., 111–135, Raven Press, New York.
Somjen, G.G., Herman, S.P. and Klein, R., 1973, Electrophysiology of methylmercury poisoning. J. Pharmacol. Exp. Ther., 186: 579.
Steriad, M. and Hobson, J.A., 1976, Neuronal activity during the sleep-waking cycle. Prog. Neurobiol., 6:155.
Sterman, M.B. and Shouse, M.N., 1985, Sleep “centers” in the brain: the preoptic basal forebrain area revisited. in: “Brain mechanism of sleep.” D.J. McGinty, ed., 277–299, Raven Press, New York.
Suzuki, T. and Miyama, T., 1971, Neurological symptoms and mercury concentration in the brain of mice fed with methylmercury salt. Industr. Health, 9:51–58.
Taylor, L.L. and DiStefano, V., 1976, Effects of methylmercury on brain biogenic amines in the developing rat pup. Toxicol. Appl. Pharmacol., 38: 489.
Uezu, E., Sano, A. and Matsumoto, J, 1981, Effects of inhibitors of protein synthesis on sleep in rats. Tokushima J. Exp. Med., 28: 9.
Verity, M.A., Brown, W.J., Cheung, M. and Czer, G., 1977, Methylmercury inhibition of synaptosome and brain slice protein synthesis: In vivo and in vitro studies. J. Neurochem., 29: 673.
Von Burg, R., Northington, F.K. and Shamoo, A., 1980, Methylmercury inhibition of rat brain muscarinic receptors. Toxicol. Appl. Pharmacol., 53: 285.
Yoshino, Y., Mozai, T. and Nakao, K., 1966, Distribution of mercury in the brain and its subcellular units in experimental organic mercury poisoning. J. Neurochem., 397.
Zimmer, L. and Cater, D.E., 1979, Effects of complexing treatment administered with the onset of methylmercury neurotoxic signs. Toxicol. Appl. Pharmacol., 51:29–38.
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Arito, H., Takahashi, M. (1991). Effect of Methylmercury on Sleep Patterns in the Rat. In: Suzuki, T., Imura, N., Clarkson, T.W. (eds) Advances in Mercury Toxicology. Rochester Series on Environmental Toxicity. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-9071-9_24
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DOI: https://doi.org/10.1007/978-1-4757-9071-9_24
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