Centrophenoxine activates acetylcholinesterase activity in hippocampus of aged rats.

Age-related changes in the acetylcholinesterase activity were measured in the hippocampus, brain stem and cerebellum of rats (aged 4, 8, 16 and 24 months). The age-dependent decrease in the enzyme activity first appeared in the hippocampus; the brain stem was affected later while the cerebellum remained unaffected. Centrophenoxine, usually considered as an ageing reversal drug and also regarded as a neuroenergeticum in human therapy, increased the acetylcholinesterase activity in the hippocampus of aged rats, the activity was also elevated in the brain stem but no in the cerebellum. The acetylcholinesterase-stimulating influence of the drug is likely to be implicated in the pharmacological reversal of the age related decline of the cholinergic system. This effect of the drug may also mediate its effects on cognitive and neuronal synaptic functions.

Lipofuscin accumulation in ageing myocardium & its removal by meclophenoxate.

A study was undertaken on the age-associated histochemical changes in the ventricular myocardium and the influence of meclophenoxate hydrochloride (MPH) on the age pigment lipofuscin. Sixty Wistar albino rats in three age-groups (3, 15 and 30 months old) were treated with meclophenoxate hydrochloride (100 mg/kg body wt/day, ip) for a period of 2-8 wk. Five animals each from the three age-groups served as controls. Various histochemical and micromorphometric studies were carried out on the myocardial tissue. A linear increase in the myocardial volume occupied by the pigment was observed with advancing age. As a result of meclophenoxate treatment, a gradual decrease in the myocardial volume occupied by the pigment was noted. After 4-6 wk treatment, the pigment bodies were found lodged into the capillary endothelium and the lumen, facilitating the removal of the pigment via blood stream. Histochemical and micromorphometric analyses of ventricular myocardium of albino rats have shown thus that deposition of the age-pigment, lipofuscin, can be accepted as an index of cellular ageing.

'Dark' cell formation under protein malnutrition: process of conversion and concept of 'semi-dark' type Purkinje cells.

This paper deals with some deleterious effects of protein malnourishment in rat cerebellum. Severe protein deprivation enhanced the formation of 'dark' cells in white rats. It is postulated that abnormal changes in the neuronal contents induced by nutritional stress play a vital role in the formation of the 'dark' cells through an intermediary stage, 'semi-dark' cells. Centrophenoxine a lipofuscinolytic agent, however, seems to interfere with the process of formation of 'dark' cells and/or helps reconversion of the 'dark' cells into the normal or 'light' type Purkinje cells.

The effect of centrophenoxine at the skeletal neuromuscular junction.

Centrophenoxine exhibited some interesting actions at the neuromuscular junction. The drug was ineffective in rat or chick preparations, but blocked neuromuscular transmission in frog preparations. The blockade was reversed by adrenaline, potassium, choline and physostigmine. The drug had no effect on muscle contractility or endplate cholinoceptor. Hemicholinium 3 induced a neuromuscular blockade in rat (in vivo) which was reversed by choline but not by centrophenoxine. Neither of these two drugs could reverse the blocking effect of hemicholinium in frog preparations. It is concluded that centrophenoxine acts only in frog and the blockade involves a presynaptic mechanism. The work further suggests that choline uptake systems in the rat and the frog may not be identical, since choline competed with hemicholinium for the uptake system in rat and with centrophenoxine (but not with hemicholinium) in the frog.