Obestatin induces testosterone but not prolactin secretion in male Sprague Dawley rats

The present study was designed to investigate the in vivo effect of an anorcxigenic gut peptide obestatin on plasma testosterone and prolactin secretion in adult male spraunge dawley rats. one group of animals served as control (n=5). while the treatment group (n=5) received a single i.v dose of 8 nmol/kg of obestatin. blood samples (200μl-250 μl) were collected at -10,0,10,20,30 and 40 min of treatment. in treated group obestatin caused a significant (p<0.05) increase in plasma testosterone concentrations at 20 minutes. however,at 30 and 40 min post treatment,the plasma testosterone concentrations declined to non-significantly (p>0.05) higher values. a significant (p<0.05) increase in plasma testosterone concentrations was observed after treatment,compared to that before treatment. obestatin showed no profound effect on plasma prolactin concentration in all the treated groups. it was concluded that obestatin i.v infusion leads to increase in plasma testosterone in adult male rats and may thus be involved in testosterone secretion,however,it has no effect on the prolactin secretion.