PLASMA NEUROTENSIN LEVELS IN PREPUBERTAL CHILDREN AND ADULTS - POSSIBLE INVOLVEMENT IN THE REGULATION OF GROWTH-HORMONE SECRETION

The present study investigated a possible relationship between plasma neurotensin (NT) and serum growth hormone (GH) levels after GH-stimula tion provocative tests in humans. Samples were obtained from twelve pr epubertal children and sixteen normal adult volunteers. Basal plasma N T levels were higher in children with growth delay (19.02 +/- 4.01 fmo l/ml) (mean +/- SEM) than in normal adults (6.13 +/- 1.1 fmol/ml) (p<0 .001). Basal GH levels in children (1.52 +/- 0.06 ng/ml) were not diff erent from those in adults (0.60 +/- 0.41 ng/ml), After stimulation of GH secretion, NT values decreased when GH peaked, and increased when GH levels diminished. These data suggest that plasma NT levels may be involved in the regulation of GH secretion, as a peripheral signal, pr obably through modulation of somatostatin release from the median emin ence.