Prolactin (PRL) release in normal and growth hormone deficient children after oral metoclopramide.

Studies were done to determine plasma PRL in response to oral MC 0.2 mg/kg in 17 normal children (NC), 12 males and 5 females aged between 4.7-12.8 years and in 26 idiopathic growth hormone deficient children (IGHD), 15 M, 11 F, between 1.5-14.7 years old. Peak serum GH levels above 10 ng/ml after clonidine test and during insulin induced hypoglycemia were used to distinguish these 2 groups. None of the subjects had secondary sex characteristics. Adrenocortical and thyroid disorders were excluded. The subjects were fasted overnight. Blood samples for PRL determination were obtained at 0, 60, 90, 120 min after oral MC. In 17 NC the basal serum PRL values ranged from 0 to 19.2 ng/ml with the mean +/- SE of 7.24 +/- 1.7 ng/ml. The peak serum PRL response to MC ranges were from 33 to 127 ng/ml with the mean +/- SD and +/- SE of 64.45 +/- 24.22 and +/- 5.88 ng/ml respectively giving the cut point-2SD value of 16.01 ng/ml. Among 26I GHD, only 2 patients (7.69%) being all male, had peak PRL response to MC below 16.01 ng/ml, whereas, the rest (92.31%) had peak PRL levels above it. It is concluded that oral MC 0.2 mg/kg is the potent PRL stimulator in children, which can be safely used to test pituitary PRL secretion effectively. The majority (92.31%) of idiopathic GH deficient children had adequate serum PRL response to oral MC, whilst 7.69 per cent disclosed inadequate response which might indicate different etiologies.

Growth hormone release in normal children after oral clonidine 4 micrograms/kg.

Oral clonidine 4 micrograms/kg was given to 32 normal children, 18 males and 14 females with the mean age of 8.44 +/- 3.18 years. All were healthy and had normal growth. They were fasted overnight and throughout the test. Blood specimens were taken in the morning at 0, 30, 60, 90 and 120 minutes after clonidine ingestion. The mean basal plasma GH level was 1.81 +/- 2.07 ng/ml. The range of peak GH response was 18.7-67.3 ng/ml mostly at 90 minutes after clonidine with the mean value of 30.92 +/- 10.97 ng/ml. There were no serious undesired effects. It is concluded that with the oral dose of 4 micrograms/kg, clonidine is a safe and potent GH provocative agent with reliable and satisfactory results.