Because it intervenes in normal and pathological cerebral ageing, plays a role in late dyskinesias of Parkinson's syndrome and is involved in the memorization processes, central cholinergic neurotransmission deserves to be known with precision. Its physiological approach deals with the anatomical organization of the central cholinergic system and with the mechanisms of synthesis, release and degradation of acetylcholine and its interaction with its receptors. The pharmacological changes (inhibition or stimulation) conceivable at different levels lead to therapeutic applications.

Acetylcholine↗

PubMedDate not supplied

Effect of triethyltin chloride on the central aminergic neurotransmitters and their metabolites: relationship with pathophysiology of aging.

Triethyltin (TET) salt intoxication provokes a myelinic vacuolisation associated with a white matter cerebral edema. The central nervous system disturbances accompanying these phenomena (Na-K-ATPase activity, neurological symptoms, water and sodium cerebral content) can be counteracted by drugs used in age-related brain failure; consequently, TET intoxication could be suggested as an experimental model for studying the aging process. The aim of the present study is to follow-up the biogenic amine concentrations in different brain areas of TET treated rats, knowing that modifications of cerebral amines exist throughout the aging process. The following results are obtained: the cerebral water content of the TET treated rats is significantly increased, confirming the existence of a brain edema. Monoamine concentrations are significantly decreased, specifically noradrenaline (in hypothalamus, mesencephalon, cerebellum); serotonin (in striatum, hypothalamus, mesencephalon); dopamine only in hypothalamus; these are accompanied by an increase of the metabolites 5 HIAA (in striatum and mesencephalon) and HVA (striatum). These modifications are compared to those occurring in physiological aging, and hypothetical mechanisms are reviewed. We conclude that TET intoxication must not be considered as a pathophysiological model of brain aging, but may be considered as a useful pharmacological tool for studying experimental drugs liable to counteract brain age-induced disturbances.

3,4-Dihydroxyphenylacetic Acid↗

PubMedDate not supplied

[Effects in the guinea pig of an aerosol with a tributylitin oxide base].

The authors report a toxicological study of bis (tributyltin oxide) (TBTO) given by inhalation (oily aerosol) to 105 Hartley albino guinea pigs. Doses vary from 1 mg to 0.1 mg of TBTO per liter of aerosol. Death occurs for doses of 0.2 mg per le more resistant than the male ones. The intoxication is marked by a period of ocular and nasal irritation followed by a short remission time, then death occurs after asphyxic convulsions. With doses less than 0.2 mg per liter of aerosol, we observe only an irritation without mortality after one hour intoxication. Seven days later the animals are alive. Because of its liposulibility, TBTO is present in the whole body, particularly in liver, kidney, lung, brain and heart. Histological study does not reveal any peculiar lesion of the examinated organs. Especially there is no specific alteration of the respiratory system. The merely observed trouble is a diffuse congestion.

Aerosols↗

PubMedDate not supplied

[Modification of aminergic neurotransmitters and neurobehavioral correlates in acute cerebral ischemia in the rat].

Aminergic neurotransmitters and their main metabolites concentrations are measured in four areas (posterior cortex, striatum, hippocampus, hypothalamus) of the rat brain, 24 hours after an acute ischemic injury (created by the occlusion of the four cephalic vessels). Simultaneously, spontaneous motility and neurological status are evaluated. The main results are the increase of 5 HIAA in striatum, hippocampus and cortex, associated with an increase of HVA in striatum. Motility as well as neurological scores are significantly decreased in ischemic animals when compared with controls. The conclusion is that this model of cerebral ischemia is may be useful for pharmacological assessment of drugs liable to antagonize cerebrovascular disorders.

Animals↗

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