Central GH signalling is not required for pubertal timing
The growth hormone (GH) receptor is expressed in several regions of the brain, including leptin receptor- and kisspeptin-expressing hypothalamic neurones, which are important in regulating puberty and fertility. Bohlen et al. hypothesised that GH might play a role in regulating the hypothalamic-pituitary-gonadal (HPG) axis and the onset of puberty.
They ablated GH receptor in the whole brain, or in kisspeptin-expressing or leptin receptor-expressing neurones. While GH signalling in specific neural populations can potentially modulate hypothalamic gene expression related to the reproductive system or indirectly contribute to the progression of puberty, GH action in kisspeptin cells or in the entire brain was not required for sexual maturation. Receptor ablation in leptin receptor-expressing cells delayed puberty progression, reduced serum leptin levels, decreased body weight gain and compromised the ovulatory cycle in some individuals, while the lack of GH effects in the entire brain prompted shorter oestrous cycles.
These findings suggest that GH can modulate brain components of the HPG axis, although central GH signalling is not required for the timing of puberty.
Read the full article in Journal of Endocrinology 243 161–173