The development of genital organs of the carp can get delayed to a significant extent when subjected to stress, as per a NWO research at Utrecht University. The stress hormone, cortisol, plays a critical role in delaying puberty, according to this research.
It was assumed by the researchers that the hormone, cortisol, is behind puberty delays.
Cortisol would seem to affect the testes. It directly delays the development of reproductive cells into sperm cells. This slows the growth of the sexual organs and also the supply of steroids to the blood. During puberty, anabolic steroids from the testes ensure that the brain, the pituitary gland and testes develop properly. Because the cortisol produced under stress reduces the supply of steroids, communication to the brain and the pituitary (a gland under the brain) is reduced. This means that, like the testes, these organs develop more slowly, thus slowing down overall development.
The whole complex of hormones involved in puberty is self-regulatory. The brain produces the gonadotropin-releasing hormone, which stimulates cells in the pituitary. On order, the pituitary then excretes the gonadotropins, the luteinising hormone and the hormone which stimulates the follicles. In the testes, the gonadotropins promote the production of reproductive cells and steroid hormones. The steroid hormones contribute to the production of the reproductive cells and ensure communication between the brain and the pituitary gland, thus completing the cycle.
The finding is believed to have critical implications for medical practitioners on a worldwide basis.