Inhibition of ATPases enzyme activities on brain disturbing normal oestrous cycle.
Wistar rats treated with alpha-methyl-DL-p-tyrosine methylester showed significant level of inhibition in the activity of Na+, K+ -ATPase, Mg2+ -ATPase and Ca2+ -ATPase enzymes in different regions of the brain. The enzyme activity was assayed in cerebral hemispheres, hypothalamus, thalamus, hippocampus, amygdala and septum at proestrous (12 h), estrous (25 h), metestrous (38 h) and diestrous periods (92 h) of the rat. The Na+, K+ -ATPase activity was significantly inhibited in most of the brain regions after treated with alpha-methyl-DL-p-tyrosine methylester (MPT) and this indicated that MPT affected the active transport system and nerve impulse transmission. Mg2+ -ATPase and Ca2+ -ATPase was also significantly (P < 0.001) reduced in different regions of the brain. The results revealed that MPT affected active transport system and nerve impulse transmission by inhibiting Na+, K+ -ATPase and Ca2+ -ATPase. It has induced energy crisis by inhibiting Mg2+ -ATPase and all these cumulative effects of MPT have adversely affected the female Wistar rats. These effects have been manifested in the form of aberrations in the behavior of MPT treated female rats, which have shown their inability to perform their normal sexual activity.
Venugopal
J
J
Department of Biochemistry, NUSNNI, Division of Bioengineering, National University of Singapore, Singapore 117 576. engjrv@nus.edu.sg
Ramakrishna
S
S
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology*; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D030762:Estrous Cycle / Q000187:drug effects*; D005260:Female; D008781:Methyltyrosines / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism
D004791:Enzyme Inhibitors; D008781:Methyltyrosines; D009419:Nerve Tissue Proteins; C022260:alpha-methyltyrosine methyl ester; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase