The Story: In February 2005 Canseco released his autobiography and steroid tell-all, Juiced , Wild Times, Rampant 'Roids, Smash Hits, and How Baseball Got Big. In it he described himself as 'the chemist' having experimented on himself for years. He claimed to have educated and personally injected many players including Mark McGwire, Rafael Palmeiro, Juan Gonzalez, Ivan Rodriguez, and Jason Giambi. In his second book, Vindicated , Canseco added Magglio Ordonez to the list of players he had educated and injected with steroids. He also said he introduced Alex Rodriguez to a trainer/PED supplier after Rodriguez had asked where he could get steroids.
In most animals, steroid hormones are crucial regulators of physiology and developmental life transitions. Steroid synthesis depends on extrinsic parameters and autoregulatory processes to fine-tune the dynamics of hormone production. In Drosophila, transient increases of the steroid prohormone ecdysone, produced at each larval stage, are necessary to trigger moulting and metamorphosis. Binding of the active ecdysone (20-hydroxyecdysone) to its receptor (EcR) is followed by the sequential expression of the nuclear receptors E75, DHR3 and βFtz-f1, representing a model for steroid hormone signalling. Here, we have combined genetic and imaging approaches to investigate the precise role of this signalling cascade within theprothoracic gland (PG), where ecdysone synthesis takes place. We show that these receptors operate through an apparent unconventional hierarchy in the PG to control ecdysone biosynthesis. At metamorphosis onset, DHR3 emerges as the downstream component that represses steroidogenic enzymes and requires an early effect of EcR for this repression. To avoid premature repression of steroidogenesis, E75 counteracts DHR3 activity, whereas EcR and βFtz-f1 act early in development through a forward process to moderate DHR3 levels. Our findings suggest that within the steroidogenic tissue, a given 20-hydroxyecdysone peak induces autoregulatory processes to sharpen ecdysone production and to confer competence for ecdysteroid biosynthesis at the next developmental phase, providing novel insights into steroid hormone kinetics.
The thymus is a soft, triangular-shaped organ found in the chest posterior to the sternum. The thymus produces hormones called thymosins that help to train and develop T-lymphocytes during fetal development and childhood. The T-lymphocytes produced in the thymus go on to protect the body from pathogens throughout a person’s entire life. The thymus becomes inactive during puberty and is slowly replaced by adipose tissue throughout a person’s life.
Other Hormone Producing Organs
In addition to the glands of the endocrine system, many other non-glandular organs and tissues in the body produce hormones as well.