DEVELOPMENTAL CHANGES IN GROWTH HORMONE, INSULIN-LIKE GROWTH FACTORS (IGF-I AND IGF-II) AND IGF-BINDING PROTEINS IN PLASMA OF YOUNG GROWING PIGS

摘要: The relationship between plasma concentrations of normally secreted GH and insulin-like growth factor-I (IGF-I) was investigated in pigs after weaning. Frequent blood sampling for 12 24 h showed that pulsatile 10, 20 35 kg liveweight. Pulses were brief duration, low amplitude variable frequency. Basal average daily changed significantly with development, increasing by about 50% 10 Concentrations IGF-I little or no evidence diurnal periodicity not increased pulses. Average both IGF-II progressively liveweight, as did the total desaturated IGF-binding protein (IGFBP) activity plasma. A strong positive correlation observed concentration IGFs (IGF-I plus IGF-II) circulation IGFBP activity. developmental rise associated labelling 125I-labelled human ligand blots binding proteins apparent molecular masses greater than 200, 50, 43 29 kDa. One class 34.5 kDa decreased development. This study young growing shows endogenous exerts significant immediate control over concentrations, levels increase maturation this species.(ABSTRACT TRUNCATED AT 250 WORDS)