Simultaneous Evaluation of the Pituitary Reserve of GH, TSH, ACTH and LH in Children

Abstract

Plasma growth hormone (GH), thyrotropin (TSH), cortisol and luteinizing hormone (LH) concentrations after simultaneous intravenous administration of insulin, thyrotropin-releasing hormone (TRH) and luteinizing hormone-releasing hormone (LH-RH) were measured for the succeeding 2 hr at 30-min intervals in 14 clinically normal children, 20 patients with short stature, 17 obese children and 19 patients who had endocrine or central nervous system (CNS) disorders. In normal children, the maximal increments of plasma GH, cortisol and TSH (mean ± SD) were 17.9 ± 8.4 ng/ml, 11.0 ± 3.8 μg/100 ml and 13.2 ± 7.2 μU/ml, and the times of occurrence of the peak were at 60 min, 60 min and 30 min, respectively. No differences due to age or sex were noted. LH release, however, was low in prepubertal children (11.7 ± 5.1 mIU/ml) and increased strikingly puberty (116 ± 80 mIU/ml). Interferences between releasing hormone and insulin action by simultaneous administration were not observed. In the patients with miscellaneous endocrine or CNS diseases, low, delayed or exaggerated responses were obtained singly or concomitantly. Clinical application of this procedure will be useful for the diagnosis or investigation of pathophysiologic state of hypothalamo-pituitary axis in infancy and childhood.