The relationship between serum levels of prolactin and growth hormone in the early postnatal period

Hormonal Determinants of Growth and Weight Gain in the Human Fetus and Preterm Infant

The factors controlling linear growth and weight gain in the human fetus and newborn infant are poorly understood. We review here the changes in linear growth, weight gain, lean body mass, and fat mass during mid- and late gestation and the early postnatal period in the context of changes in the secretion and action of maternal, placental, fetal, and neonatal hormones, growth factors, and adipocytokines. We assess the effects of hormonal determinants on placental nutrient delivery and the impact of preterm delivery on hormone expression and postnatal growth and metabolic function. We then discuss the effects of various maternal disorders and nutritional and pharmacologic interventions on fetal and perinatal hormone and growth factor production, growth, and fat deposition and consider important unresolved questions in the field.

Prolactin response to growth hormone stimulation tests

BACKGROUND

Despite many similarities between the structure, receptors, proliferative and growth promoting actions, the relationship between Prolactin (PRL) and Growth Hormone (GH) in clinical conditions has received little attention.

OBJECTIVE

To determine the PRL response to GH stimulation tests.

SUBJECTS

Prepubertal and early pubertal boys (n = 581) and girls (n = 502) with idiopathic, non-syndromatic short stature.

DESIGN

Data was retrieved from the computerized records of the Endocrine Laboratory, Schneider Children's Medical Center. Peak GH and PRL levels during GH stimulation tests with glucagon (Gluc), Clonidine (Clon) and Clonidine with arginine (Clon+Arg), were compared. Both PRL and GH were determined by radioimmunoassay.

RESULTS

Whereas Gluc stimulated both GH and PRL to similar levels, Clon alone or combined with Arg suppressed the PRL secretion (p < 0.0001). It is also evident that in both boys and girls Clon alone and Clon±Arg are superior to Gluc in GH stimulation. The higher GH levels during Clon+Arg than with Clon alone are attributed to the pubertal stage.

CONCLUSION

This study provides further information on the Prolactin-Growth hormone relationship in children.