Saturday, August 26, 2006

Works of Late Professor Raj Shankar

Author: Abhinav Shankar

Late Professor Raj Shankar

Late Dr. Raj Shankar (1947-2000), Late Professor, Department Of Biochemistry, Institute Of Medical Sciences, Varanasi , Uttar Pradesh-221005, INDIA

His main fields of specialization were Neurobiochemistry and Clinical Biochemistry.His contributions on neurochemistry are well recognized and he had been invited to deliver lectures in various prestigious conferences.Professor Raj Shankar's contribution is in developmental neurobiology with special reference to undernutrition during brain growth spurt period.His work had clearly established that undernutrition during brain development causes some irreversible changes.In 1991,work carried out in Texas and Yale with Magnetic Resonance Imaging by other workers confirmed some of the conclusions of Prof Shankar's work.Work done during last few years on developing brain show that signal transduction mechanisms are affected due to nutritional stress during brain development.Professor Shankar's other work involved biochemical aspects of mode of action of drugs on C.N.S.Apart from work on reserpine done earlier and published in NATURE and BIOCHEMICAL PHARMACOLOGY,in 1987 he established that the barbiturate pentobarbitone affects protein phosphorylation in brain.This work is significant from the point of view of views on signal transduction.His work also concerned with mode of action of drugs like haloperidol and trifluoperazine.Professor Shankar's work in clinical biochemistry was mainly concerned with lipoprotein metabolism.Professor Shankar has over 50 publications in international and national Journals of repute.

The brief history of Research work done by him & his contributions to Neuro-Chemistry and Bio-Chemistry :

He worked for one year (1966-67) in the Vallabhbhai Patel Chest Institute,University Of Delhi,India on the Lipid Metabolism In Mycobacteria.In 1967,he went to Kinsmen Laboratory of Neurological Research,University Of British Columbia,Canada to work under Prof.J.H. Quastel, F.R.S. for PhD degree in Biochemistry.There he worked On ""Cerebral Metabolism during Anoxia and effect of some Neurotropic Drugs"".This work clearly showed that tetrodotoxin strongly stimulates anaerobic glycolysis and these findings led to the conclusion that at the onset of anoxia,and in the absence of tetrodotoxin action potentials are generated. The above work has been cited in various publications by a number of workers.In 1971,he returned from abroad and joined Department Of Biochemistry ,Institute Of Medical Sciences,Banaras Hindu University,Varanasi,India.There he initiated work on undernutrition and brain development.His early work was concerned with developing a suitable model for study of effect of undernutrition on cerebral metabolism during the brain growth spurt period.Ultimately the method of restriction feeding time of the suckling rats was adopted and he found that transport property of isolated cerebral tissue is altered in developing rats .This was perhaps first demonstration of the fact that undernourishment during brain growth spurt period causes changes in the membrane organization resulting in altered transport properties.It was also found that a key membrane enzyme Na+K+ ATPase show decreased activity in addition to changes in pattern of oubain inhibition which was reversible on adequate rehabilation.This work along with some other findings of him show that these changes are presumably due to the free radical induced damage to developing brain.

Studies on incorporation of C14-acetate into brain lipids of undernourished rats in vivo carried out by him showed that inspite of lipid deicit, 14C-acetate incorporation is slightly higher in experimental animals.This finding ultimately led to the observation that operation of pentose phosphate cycle is altered in the brains of undernourished animals.Gultathione and ascorbic acid was also studied in undernourished brain. From 1980-84 he worked on a project ""Drug Action ,brain development and behavioral changes in the mammalian system ""financed by CSIR(India).This work mainly led to the finding that action of some CNS acting drugs are potentiated in undernourished animals.They also observed that the drug reserpine is a strong inhibitor of lipid peroxidation and protein phosphorylation in brain.This project was mainly concerned with interaction between drug action,monoamines and membrane phenomenon which could later be extra polated to behaviour.Since various gangliosides are involved in binding of cerebral amines the contents of different species of gangliosides and neuraminidase activity was established.He established that the drug reerpine effects the cationiv content of rat brain and proposed that changes in cationic content may be playing a part in release of monoamines at the synapse.It was further shown that transport property of isolated cerebral tissue is altered in chronic reserpinized animals which further pointed out the membrane action of reserpine.In 1980 he established that there is a relationship between high density lipoproteins and premature atherosclerosis in patients with renal failure.The work on lipoproteins was also carried out with patients suffering from anxiety neurosis.He was one of the coinvestigators in an international study on protein energy requirements in indivisuals of this country and this work was supported by the United Nations University.In addition he was involved in a number of collaborative studies with various groups in the institute.The studies include Biochemical and Immunological studies in chylurya,placental oxidative enzymes in pregnancy anemia,Lecithin-Sphingomyelin ratio in fetal lung maturity etc.Till August 2000 he was involved in study of protein phosphorylation in brain.He had shown that protein phosphorylation is adversely on rehabilation .Attempts were in progress to characterize specific proteins by SDSPAGE and radioautography.He had shown the effect of pentobarbitone on cerebral protein phosphorylation which is not due to to its action on electron transport chain.Work was also in progress in his laboratory till August 2000 to study effect of a number of CNS drugs on protein phosphorylation in brain and to examine if specific proteins are effected.This would have helped to establish exact role of cerebral phosphoproteins in neurotransmission.Mechanism of action of some antiepileptic drugs on brain metabolism was also in progress.In 1999 he conclusively established that in conditions like Alzeihmer's disease there is phosphorylation related folding problem of proteins.This is responsible for cognitive and other defects.Similar situation exists under severe undernutrition during brain growth spurt period and similar mechanism involving protein phosphorylation may be involved here also. In 2000 along with his student Kalyan Goswami,he showed that sites in proteins damaged due to free radicals can be accurately determined by carbonylation studies and may be developed as an accurate method to denote relation between chronological age and biological age after free radical induced damage.(Kalyan Goswami,B.D. Bhatia ,Raj Shankar, 2000)


About the author: Abhinav Shankar, Student, Dr.BR Ambedkar University,Agra,UP,India


Post a Comment

Links to this post:

Create a Link

<< Home