L 5936 (OTTO) Leptin from rat ≥97% (SDS-PAGE), recombinant, expressed in E. coli, lyophilized powder-has been used to check the effect of intranasal nerve growth factor (NGF) on NGF activity in the spinal cord of Sprague-Dawley rats.for validation of labelling for leptin-bearing cells of Sprague-Dawley rats