Nandrolone and other anabolic androgenic steroids alter the expression and function of neurotransmitter systems and contribute to drug dependence. Nandrolone treatment (10-10 M) caused a time-dependent and concentration-dependent downregulation of mu opioid receptor (MOPr) transcripts in SH-SY5Y human neuroblastoma cells. This effect was prevented by the androgen receptor antagonist hydroxyflutamide. Receptor binding assays confirmed a decrease in MOPr of approximately 40% in nandrolone-treated cells. Treatment with actinomycin D (10 (-5)M), a transcription inhibitor, revealed that nandrolone might regulate MOPr mRNA stability. In SH-SY5Y cells transfected with a human MOPr luciferase promoter/reporter construct, nandrolone did not alter the rate of gene transcription. These results suggest that nandrolone may regulate MOPr expression through posttranscriptional mechanisms requiring the androgen receptor.
Heavy consumption of the essential amino acid lysine (as indicated in the treatment of cold sores) has allegedly shown false positives in some and was cited by American shotputter C. J. Hunter as the reason for his positive test, though in 2004 he admitted to a federal grand jury that he had injected nandrolone.  A possible cause of incorrect urine test results is the presence of metabolites from other AAS, though modern urinalysis can usually determine the exact steroid used by analyzing the ratio of the two remaining nandrolone metabolites. As a result of the numerous overturned verdicts, the testing procedure was reviewed by UK Sport . On October 5, 2007, three-time Olympic gold medalist for track and field Marion Jones admitted to use of the drug, and was sentenced to six months in jail for lying to a federal grand jury in 2000. 
Anabolic steroids are synthetic versions of hormones that human body produces naturally. Their main role is to assure increased physical performance in all sports and athletic pursuits. Steroidal compounds enhance stamina, strength, weight and size of muscles and may improve the energy levels during physical training. Oral and injectable steroids posses the ability to increase athletic performance, have a positive effect on red blood cells production and bones density. The steroids are used in accordance with requirement and needs of any athlete individually. There are special compounds which are not suitable for women and a series of anti-estrogen products which main role is to counter the eventual side effects of steroids use and to restore natural testosterone levels of the human body. These compounds nowadays became an important part of muscle building process among professional athletes and bodybuilders, as well as regular people, males and females that have the goal to become more attractive and exhibit good looks. Follow us on Twitter | Steroids Store - Pinterest .