Human growth hormone produced in tissue culture: Characterization by poly acryl amide gel electrophoresis

Human growth hormone (HGH) produced in culture by pituitary adenomas from 2 acromegalic patients or by 2 normal pituitaries in culture was subjected to polyacrylamide gel electrophoresis at various pore sizes and pH’s and was found to be indistinguishable in size from HGH standard (HS 705 A). HGH was the predominant protein synthesized by the adenoma cultures. Two main bands of HGH were found. One adenoma synthesized a species of HGH with a relative mobility (R_f) identical with the standard (HGH-B). The other produced HGH identical in R_f with a species of hormone (HGH-A) which has been shown to have the same size, but decreased net charge when compared to the standard. The species of HGH produced by each of the 2 adenomas remained constant with time in culture. In contrast, HGH represented a small fraction of total secretory protein in the cultures of normal pituitaries. The HGH species extracted from the cultures of normal pituitaries were not constant with time in culture; bands of HGH exhibited R_f values which increased progressively over 60 days in culture.