ABSTRACT
The effect of drugs from the class of cardiac (methyldigoxin, verapamil, propranolol), antiepileptic (carbamazepine), sedative (diazepam) and antihistaminic (promethazine) drugs on Na+, K+-ATPase activity of plasma membranes in rat brain synaptosomes was studied. Methyldigoxin in concentration of 0.1 mmol L-1 inhibits enzyme activity by 80%. Verapamil, propranolol and promethazine in concentrations of 20, 20 and 2 mmol L-1, respectively, inhibit entirely this ATPase activity. Carbamazepine and diazepam in concentrations of 0.02-60 mmol L-1 have no effect on the activity of this enzyme. According to drugs concentrations that inhibit 50% of enzyme activity (IC50), the potency order of drugs was: methyldigoxin >> promethazine > verapamil => propranolol. From inhibition of commercially available purified Na+, K+-ATPase isolated from porcine cerebral cortex in the presence of chosen drugs, as well as from the kinetic studies on synaptosomal plasma membranes, we may concluded that the drugs inhibit enzyme activity, in partly by acting directly on the enzyme protein. Propranolol, verapamil and promethazine inhibitions were in an uncompetitive manner. The results suggest that these three drugs may contribute to neurological dysfunction and point out to the necessity to take into consideration the side effects of the investigated drugs during the treatment of various pathological conditions.
PDF References Citation
How to cite this article
Z.I.A. AL-Fifi, 2006. Effect of Drugs from the Class of Cardiac on the Na+, K+-ATPase Activity. Journal of Biological Sciences, 6: 968-977.
DOI: 10.3923/jbs.2006.968.977
URL: https://scialert.net/abstract/?doi=jbs.2006.968.977
DOI: 10.3923/jbs.2006.968.977
URL: https://scialert.net/abstract/?doi=jbs.2006.968.977
REFERENCES
- Balzan, S., G. D'Urso, S. Ghione, A. Martinelli and U. Montali, 2000. Selective inhibition of human erythrocyte Na+/K+ ATPase by cardiac glycoside and by mammalian digitalis like factor. Life Sci., 67: 1921-1928.
Direct Link - Bloj, B., R.D. Morero, R.N. Faias R.E. and Trucco, 1973. Membrane lipid fatty acids and regulations of membrane-bound enzymes. Allosteric behavior of erythrocyte Mg2+-ATPase, (Na+K+)- ATPase and acetylcholinesterase from rats fed with different fat-supplemented diets. Biochem. Biophys. Acta, 311: 67-79.
- Ewart, H.S. and A. Klip, 1995. Hormonal regulation of the Na+-K+-ATPase: Mechanisms underlying rapid and sustained changes in pump activity Am. J. Physiol.-Cell Physiol., 269: C295-C311.
Direct Link - Pekovic, S., N. Nedeljkovic, G. Nikezic, A. Horvat, M. Stojiljkovic, L. Rakic and J.V. Martinovic, 1997. Biochemical characterization of the hippocampal and striatal Na,K-ATPase reveals striking differences in kinetic properties. Gen. Physiol. Biophys., 16: 227-240.
PubMedDirect Link - Rodriguez de Lores Arnaiz, G. and C. Pena, 1995. Characterization of synaptosomal membrane Na+, K+-ATPase inhibitors. Neurochem. Int., 27: 319-327.
CrossRefDirect Link