Related Experiment Videos
Prolactin (PRL) release in normal and growth hormone deficient children after oral metoclopramide
C Preeyasombat1, P Mahachoklertwattana, A Sriphrapradang
1Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Insights
Oral medication (MC) effectively stimulates prolactin (PRL) secretion in children. Most idiopathic growth hormone deficient children showed an adequate PRL response, suggesting MC is a safe pituitary function test.
Area of Science:
- Pediatric Endocrinology
- Hormone Secretion Testing
- Growth Hormone Deficiency
Background:
- Assessing pituitary prolactin (PRL) secretion is crucial for diagnosing endocrine disorders in children.
- Idiopathic growth hormone deficiency (IGHD) requires comprehensive pituitary function evaluation.
- Oral medications offer a potentially safer and more effective method for stimulating hormone release compared to invasive tests.
Purpose of the Study:
- To evaluate the efficacy of oral medication (MC) at 0.2 mg/kg as a prolactin (PRL) secretagogue in children.
- To determine the PRL response to oral MC in normal children (NC) and children with idiopathic growth hormone deficiency (IGHD).
- To establish a reference range for PRL response to oral MC and assess its utility in identifying potential etiologies of IGHD.
Main Methods:
- Plasma PRL levels were measured in 17 NC and 26 IGHD children at baseline and at 0, 60, 90, and 120 minutes after oral administration of MC (0.2 mg/kg).
- Children with IGHD were previously diagnosed based on peak serum GH levels above 10 ng/ml following clonidine and insulin tolerance tests.
- Exclusion criteria included secondary sex characteristics and adrenal or thyroid disorders; subjects were fasted overnight.
Main Results:
- In normal children, basal PRL ranged from 0 to 19.2 ng/ml (mean ± SE: 7.24 ± 1.7 ng/ml).
- Peak PRL response to oral MC in NC ranged from 33 to 127 ng/ml (mean ± SD: 64.45 ± 24.22 ng/ml), with a cut-off of 16.01 ng/ml (2 SD below the mean).
- Among 26 IGHD patients, 92.31% exhibited peak PRL levels above 16.01 ng/ml, while 7.69% (all males) showed a blunted response (<16.01 ng/ml).
Conclusions:
- Oral MC at 0.2 mg/kg is a potent and safe PRL stimulator for pediatric pituitary function testing.
- The majority of IGHD children demonstrate an adequate PRL secretory response to oral MC.
- A small percentage of IGHD children with inadequate PRL response may represent distinct etiological subgroups requiring further investigation.
Abstract:
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.