Plasma lipotropin increase in man after growth hormone administration. Comparison between extractive and biosynthetic...

The action of human growth hormone (hGH) on plasma lipotropins (beta-and gamma-LPH) in 15 GH deficient patients was studied by comparing the effects induced by the acute administration of the extracted and biosynthetic molecules. The purified extracted preparation (6 mg/m2 im) induced a dramatic rise in plasma LPH: basal (49 +/- 12 pg/ml (mean +/- SEM); peak 1,658 +/- 262 pg/ml. The same dose of biosynthetic methionyl-hGH (met-hGH) induced no significant change in plasma LPH. Both preparations caused identical plasma GH increases. Six different commercially available extracted hGH preparations (Choay, France; Serono, Italy; France Hypophyse, France; Kabi, Sweden; Nordisk, Denmark; International Standard, Great Britain) all showed definite cross-reactivity in the LPH radioimmunoasay, varying from 0.1 to 1.0%, on a weight basis. No cross reactivity was found with met-hGH (less than 0.0001%). On gel exclusion chromatography, the LPH immunoreactivity of the purified preparations was dissociated from the GH immunoreactivity and eluted at the position of beta-and gamma-LPH. These data show that extracted hGH preparations are all contaminated with LPH and raise the question of the possible consequences of chronically elevated plasma LPH in treated patients. The use of biosynthetic met-hGH should prevent this occurence.