Growth hormone receptor gene expression in puberty

Area of Science:

• Endocrinology
• Pediatric Endocrinology
• Growth Hormone Physiology

Background:

• The synergistic effects of growth hormone (GH) and other hormones during the pubertal growth spurt are not fully understood.
• The Growth Hormone/Insulin-like growth factor-I (GH/IGF-I) axis plays a crucial role in pubertal development.

Purpose of the Study:

• To investigate the role of the GH/IGF-I axis during the pubertal period in females.
• To evaluate serum IGF-I, growth hormone binding protein (GHBP), and growth hormone receptor (GHR) gene expression in prepubertal, pubertal, and adult females.

Main Methods:

• A cohort of 64 Caucasian females (22 prepubertal, 26 pubertal, 16 adult) was studied.
• Serum IGF-I and GHBP levels were measured.
• Quantitative GHR gene expression in peripheral lymphocytes was assessed using real-time PCR.

Main Results:

• Pubertal girls exhibited significantly higher IGF-I levels (441.95±29.42 ng/ml) compared to adult women (148±10 ng/ml) and prepubertal girls (166.34±18.85 ng/ml).
• Serum GHBP levels were significantly higher in prepubertal girls (127.02±20.76 ng/ml) than in pubertal girls (16.63±2.97 ng/ml) and adult women (19.95±6.65 ng/ml).
• GHR gene expression was highest in pubertal girls, though the difference was not statistically significant across all groups.

Conclusions:

• Sexual hormones may positively influence GH/IGF-I axis action during puberty.
• This influence appears to occur through increased GHR messenger RNA (mRNA) production and reduced GHR cleavage, impacting GHBP levels.