Serotonin/growth hormone/insulin-like growth factors axis on pre- and post-natal development: a contemporary review

Introduction L-tryptophan (L-Trp) is the precursor ofserotonin (5HT). 5HTregulates the secretion of pituitary growth hormone (GH), whichin turn stimulates production of insulin-like growth factors (IGFs). IGFs are necessary for development andgrowth. In this review, we considered the influence of different growth factors and hormones on pre- and post-natal development.We reviewed the most recent literature regarding the role of 5HT / GH / IGF-I axis on development and growth.Literature widely reports the link between 5HT, GH and IGFs production. Many data show impaired growth and development in offspring of pregnant rats with low levels of plasmatic 5HT. The most recent literature shows the possible negative influence of 5HT in excess on differentiation of serotonergic neurons with consequent reduction in pituitary GH production, which has a direct effect on hepatic production of IGF-I, particularly in the post-natal period. Recent literature shows that hyperserotonemia in pregnant rats causes disorders in offspring, such as a lower body mass and a lower survival rate. In addition, data show that high 5HT levels could inhibit development of 5HT neurons and lead to anatomic and functional alterations of the brain. Alsoarecent our study supports the negative effects of hyperserotonemiaon pre-and post-natal development.ConclusionPre-and post-natal development depends on genetic, environmental factors and several growth factors. The ability of the placenta to provide the fetus for all molecular components is fundamental to allow a normal development and growth. This review expresses brief considerations on some aspects of pre-and post-natal development. It gives a synthetic overview on the role of 5HT / GH / IGF-I axis on development and growth.