Likewise, a novel isoform of ERβ, termed ERβ2, containing an in-frame insertion of an exon of 54 nucleotides, resulting in an insertion of 18 amino acids in the LBD, was recently identified first by screening rat prostate cDNA library, and is also expressed in human cell lines. 43 ERβ2 binds E 2 with lower affinity (Kd = 8 nM) than ERβ1 (Kd = 1 nM). At least 10 splice variants of ERβ have been identified. 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55
Anabolic steroid hormones are synthetic substances that are related to the male sex hormones. They have the same mechanism of action within the body. Anabolic steroid hormones stimulate the production of protein, which is used to build muscle . They also lead to an increase in the production of testosterone. Testosterone is the hormone responsible for the development of male reproductive organs and male secondary sex characteristics. Testosterone is also critical in the development of lean muscle mass. Anabolic steroid hormones also promote the release of the growth hormone which stimulates growth, especially skeletal growth.