Serum AChE Research Articles

Stimulation of acetylcholinesterase activity with nyctanthes arbor‐tristis leaves extract in the malathion‐treated immunosuppressed mice

The central nervous system's immune interaction appears to play a role in the psychosocial influence on immunologically resisted and mediated disease. Malathion is a known inhibitor of acetylcholinesterase activity. The accumulation of acetylcholine in nerve tissue affects organs with consequent symptoms that mimic the central nervous system action of acetylcholine. Subchronic and sublethal doses of malathion also suppressed the immune response. Nyctanthes arbor‐tristis has a immunopotentiative and pesticidal property. The effects of Nyctanthes arbor‐tristis on acetylcholinesterase (AchE) activity in the serum and brain was studied by treating the Swiss albino mice with an aqueous extract of N. arbor‐tristis [HL(aq)], as well as malathion‐immunosuppressed mice. The results revealed that the inhibition of AchE activity is reduced in malathion‐treated serum and brain tissue samples of mice, when they were given a HL(aq) extract treatment. Moreover, there was greater enhancement of AchE in serum than in brain tissue samples in HL(aq)‐treated mice. Thus the effect of malathion on AchE activity can be antagonised by HL(aq) treatment.

RECORDED CHANGES IN SOME BIOCHEMICAL INDICATORS OF GRASSCARP CTENOPHARYNGODON IDELLA EXPOSED TO MERCURY AND ZINC

^J.rass carp Ctenopharyngodon idella, fingerlings were exposed to lethal and sublethal concentrations of mercury and zinc. The changes in haemoglobin (Hb) haematocrit (Ht), osmolality, branchial Na+-K+-ATPase5 acetylcholinesterase (AchE), sodium (Na*); potassium (K*) and water content were recorded. Blood Hb and Ht showed a general trend of significant decrease in exposed to lethal and sublethal concentrations of mercury and zinc. The serum osmolality showed a significant increase on exposure offish to lethal and sublethal concentrations of mercury and zinc. In fishes exposed to lethal concentration of mercury and sublethal concentration of mercury and zinc, the activity of branchial Na+-K+-ATPase was increased, while in case of lethal exposure to zinc, the enzyme activity was reduced. Serum AchE activity decreased in exposed to lethal concentration of mercury and sublethal concentration of zinc. On the other hand, the enzymatic activity was increased in fishes exposed to lethal concentration of zinc and sublethal concentration of mercuiy. In case of brain, the AchE activity increased in fishes exposed to lethal concentration of mercury and zinc and decreased in fishes exposed to sublethal concentration of mercuiy and zinc. The concentrations of (Na+, K4) in serum, liver and muscle were significantly increased when fish were exposed to either lethal or subletlial treatments. The water content of liver

Levels of cerebrospinal fluid and serum acetylcholinesterase in Tuberculous and pyogenic meningitis in children

Total acetylcholinesterase activity (AChE) was estimated in CSF and serum of 163 cases, comprising of 64 cases of Tuberculous meningitis (TBM), 60 cases of pyogenic meningitis (PM) and 30 control in the paediatric age group. Mean CSF-AChE levels were 7.94±0.38, 9.06±0.16 and 9.80±0.30 unit/ml (Mean±S.E.) in Control, TBM and PM respectively. The respective serum AChE levels were 2.65±0.13, 3.18±0.07 and 3.93±0 0.035 units/ml. The ratio of CSF/serum-AChE in three groups were 3.09±0.137 (Mean±S.E.), 2.88±0.087, 2.98±0.092 in control, TBM and PM respectively. The values in both CSF as well as in serum in patient with TBM and in PM were significantly higher as compared to controls. However, the differences between the mean CSF-AChE and serum-AChE levels and CSF-AChE/serum-AChE were insignificant. Thus, though AChE levels are raised in meningitis, they are not helpful in differentiating TBM from PM.

Serum acetylcholinesterase possesses trypsin-like and carboxypeptidase B-like activity

Acetylcholinesterase (AChE, EC 3.1.1.7) purified from the electric organ of eel possesses a protease activity resembling that of a neuropeptide processing enzyme. To examine whether any mammalian AChEs possess a similar protease activity, the enzyme was purified, 110,000-fold from foetal bovine serum. Purified serum AChE cleaved 2 synthetic peptide substrates in a manner resembling the combined actions of trypsin-like and carboxypeptidase B-like enzymes. A synthetic fragment of preproenkephalin A (residues 97–107) containing a complete methionine-enkephalin sequence was cleaved by serum AChE to yield free methionine-enkephalin. The carboxypeptidase action of AChE was weakly stimulated by the presence of 100 μM CoCl 2 suggesting the requirement of a metal ion for complete activity. The results support the hypothesis that in many tissues AChE may act as a neuropeptide processing enzyme.

A study of nerve conduction velocity, late responses and neuromuscular synapse functions in organophosphate workers in India.

To study the effect of occupational organophosphate exposure on neuromuscular function, 24 workers exposed to fenthion [0,0-dimethyl-0(4-methyl mercapto-3 methyl phenyl)phosphorothioate], whose mean age was 31.7 years (range 22-50) and mean duration of exposure to fenthion 8.5 years (range 1-19) were subjected to detailed clinical and neurophysiological evaluation after spraying. The neurophysiological tests included motor and sensory nerve conduction velocity; F response, H reflex and electromyographic neuromuscular synapse testing. Fenthion exposure was monitored by serum acetyl cholinesterase (AchE) levels. The observations were repeated after withdrawing the workers from fenthion exposure for 3 weeks to study the reversibility of the observed changes. There was no clinical evidence of peripheral neuropathy or muscle weakness. However, peroneal motor conduction velocity (p less than 0.05) terminal motor latency of median (p less than 0.1), and peroneal nerve (p less than 0.05); F minimal latency and H reflex latency (p less than 0.01) were significantly affected. Twenty-nine per cent of workers had repetitive muscle activity. Serum AchE levels also showed significant changes (p less than 0.01). The clinical significance of these subtle neurophysiological changes requires further investigation and follow-up.