en پژوهشي Research Article Suppression of Akt (Protein kinase B) has been implicated in schizophrenia, the effect which has been documented to be reversed by tyrosine phosphatase inhibition. T hus, present study has been designed to study the effect of sodium orthovanadate, a tyrosine phosphatase inhibitor, on protracted methionine administration induced schizophrenia like behavior in rats.   Schizophrenia like behavior was assessed in number of circuits of cage (locomotor activity), number of climbs of sides (climbing), number of rears, face washing, scratching and chewing (stereotypy).   M ethionine administration (1.7 g / kg/ d, p.o.) for a period of 30 days elicited schizophrenia like behavior in rats as assessed in terms of locomotor activity, climbing and stereotypy. However, sodium orthovanadate (15, 30 & 60 mg / kg, i.p.) coadministered from day 15 to day 30 markedly reduced this methionine induced increase in locomotor activity (from 40 ± 5.45 to 22 ± 2.82), climbing (from 57 ± 4.05 to 22 ± 2.12) as well as stereotypy (from 159 ± 6.9 to 59 ± 3.9).Therefore, sodium orthovanadate treatment caused reversal of protracted methionine administration induced schizophrenia like behavior in rats reflected that inhibition of tyrosine phosphatase might be a useful approach in the therapeutics of schizophrenia. 67 0 http://ijpt.iums.ac.ir/browse.php?a_code=A-10-100-119&slc_lang=en&sid=1 Ashish Kumar Rehni 1003194753284600373 1003194753284600373 No Nirmal Singh 1003194753284600374 1003194753284600374 No Seema Jindal 1003194753284600375 1003194753284600375 No