Steroid hormones‘ intermittent signaling can affect gene expression in rodents according to a research by scientists at the University of Bristol and the National Cancer Institute (NCI), USA.

The finding is believed to provide invaluable insight to understand as to why steroids work along with creating novel avenues for new therapies.

The findings of this study are published online and expected to appear in the September 2009 issue of Nature Cell Biology.

From News-Medical.Net:

Glucocorticoid hormones, which were investigated in this study, are steroid hormones secreted by the adrenal glands that are involved in a large variety of animal and human physiological responses.

Glucocorticoids act through the glucocorticoid receptor, which is expressed in almost every cell in the body and regulates genes controlling development, metabolism, and immune response.

Studies of the glucocorticoid receptor typically assess gene responses after long-term stimulation with synthetic hormones. However, such treatments may not fully replicate the actual situation in living animals because, in addition to being released from the adrenal glands in a 24-hour circadian pattern, these hormones are also released in a pulsing mode, cycling approximately every hour, in what is referred to as ultradian cycling.

In this new study, the researchers demonstrate that ultradian hormone stimulation induces the pulsed expression of genes (known as gene pulsing) over the same period, both in cultured cells and in animal models. Initially, the researchers administered corticosterone, a naturally occurring glucocorticoid hormone in rodents, in a pulsed manner to cultured mouse cells and then observed that the levels of newly synthesized RNA from glucocorticoid receptor-regulated genes tracked precisely with the hormone pulses.

Professor Stafford Lightman, head of the Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, at the University of Bristol, remarked that cortisol gets gradually released in pulses in rodents and humans. It was also remarked that the study suggests this hormonal pattern release is important for sound health and providing a novel concept for new drug design.

Italian player Eduardo Carlos Morgado Oliveira gets a two-year ban for testing positive for anabolic steroids (specifically nandrolone) metabolites. The doping control that got Oliveira took place on Oct.18 in the match for third place between Russia and Italy at the FIFA Futsal World Cup Brazil 2008.

Nandrolone is most commonly sold commercially as Deca-Durabolin (decanoate ester) and Durabolin (phenylproprionate ester). Nandrolone is used in the treatment of osteoporosis in postmenopausal women and certain forms of anemias. .

Liberian player Melvin King receives a five-month ban after testing positive for a glucocorticoid at a doping control after the match of the preliminary competition of the 2010 FIFA World Cup. The match took place between Senegal and Liberia on 21 June 2008.

A glucorticoid is a steroid hormone that is used a performance-enhancing drug since it can is involved in the metabolism of carbohydrates, protein, and fat in the body.