Circular IGFBP-3 level affected by the gene transfer of different growth hormone isoforms

To evaluate whether through gene transfer, which growth hormone (GH) isoform can influence the circulation IGFBP-3 level, mice were injected three times with the human cytomegalovirus (CMV) mediated mammalian expression vector encoding different GH isoform gene. Then blood samples were drawn and the ELISA method was used to determine the circulation concentration of IGFBP-3. It was found that the 22 kDa GH gene could increase IGFBP-3 levels to 1.94 microg/ mL whereas 20 kDa GH, 17 kDa GH and 5 kDa GH genes did not play a role in the circulation expression of IGFBP-3.