Article révisé par les pairs
Résumé : The purpose of the study was to investigate in normal subjects whether the apparent fall in somatomedin activity previously described during insulinic hypoglycemia was due to a decrease in somatomedin-C (Sm-C). Hypoglycemia was induced in 10 normal men 21-37 years old by iv injection of 0.12 U/kg of insulin 'Actrapid' Novo. Plasma glucose decreased from a basal value of 90 ± 1 mg/dl (mean ± SE) to a nadir of 25 ± 3 mg/dl at 25 min; in all subjects, the nadir was below 33 mg/dl. GH levels increased to peak values higher than 14.5 ng/ml. Basal Sm-C values averaged 0.78 ± 0.08 U/ml. No significant variations were observed for 120 min after insulin injection; mean Sm-C levels ranged from 0.74 ± 0.07 U/ml (at 90 min) to 0.88 ± 0.10 U/ml (at 30 min). These findings indicate that the fall in somatomedin activity previously reported is likely due to the release of an inhibitory factor.