Muscle androgens

The pharmaceutical industry has developed and studied a number of anabolic steroids for use in veterinary medicine and in rehabilitation from injuries that are accompanied by deterioration of muscles. The ideal agent would be one that possessed the anabolic properties of testosterone without its androgenic (masculinizing) effects. Methandrostenolone (Dianabol) and stanozolol are among the many synthetic anabolic steroids that require a prescription. 

Sex Hormones Testosterone and androsterone are the two most important male sex hormones, or androgens. Androgens are responsible for the development of male secondary sex characteristics during puberty and for promoting tissue and muscle growth. Both are synthesized in the testes from cholesterol. Androstenedione is another minor hormone that has received particular attention because of its use by prominent athletes. 

Androgens, represented by testosterone, are male sex hormones involved in reproduction, behavior, and bone and muscle growth. 

Androgens act via the AR and play an important role in the development and differentiation of the male sexual organ. Furthermore, they are involved in several diseases, the most important being partial and complete androgen insensitivity syndrome (AIS formerly known as the testicular feminization syndrome), spinal and bulbar muscle atrophy (SBMA Kennedy s disease), and the neoplastic transformation of the prostate. The two natural occurring androgens are testosterone (T) and the... 

Androgens are important for general sexual function and libido, but testosterone supplementation is only effective in patients with documented low serum testosterone levels. In patients with hypogonadism, testosterone replacement is the initial treatment of choice, as it corrects decreased libido, fatigue, muscle loss, sleep disturbances, and depressed mood. Improvements in ED may occur, but they should not be expected to occur in all patients.23 The initial trial should be for 3 months. At that time, re-evaluation and the addition of another ED therapy is warranted. Routes of administration include oral, intramuscular, topical patches or gel, and a buccal tablet. 

SBMA In addition to HD, NaBu has also been reported to be effective in treating spinal and bulbar muscular atrophy (SBMA) (Minamiyama et al, 2004), an inheritable motorneuron disease caused by an expanded polyglutamine-repeat within the androgen receptor. SBMA is associated with motorneuron loss in the spinal cord and brain stem as well as a sub-clinical loss of sensory neurons in the dorsal root ganglia resulting in skeletal muscle atrophy and weakness (Sobue et al, 1989 ... 

The absence of appropriate androgen signaling in patients with SMA diminishes protein synthesis, especially in muscle, contributing to decreased muscle mass. The product normally encoded by the SMA gene would best be described as a... 

Finasteride inhibits 5a-reductase, the enzyme converting T. into dihydrotestosterone (DHT). Thus, the androgenic stimulus is reduced in those tissues in which DHT is the active species (e.g., prostate). T.-dependent tissues or functions are not or hardly affected (e.g., skeletal muscle, negative feedback inhibition of gonadotropin secretion, and libido). Finasteride can be used in benign prostate hyperplasia to shrink the gland and, possibly, to improve micturition. 

Testosterone is the most important of the male sexual steroids (androgens), it is synthesized in the Leydig intersitial cells of the testes, and controls the development and functioning of the male gonads, it also determines secondary sexual characteristics in men (muscles, hair, etc.). 

A number of studies were conducted in order to try and create a drug with high-androgenic and low-anabolic potential however, most attempts were unsuccessful. Because they are structurally similar to testosterone, they exhibit both androgenic and anabolic activity, and are frequently used by athletes for building up muscle mass. At the same time, all of the anabolics currently used have androgenic activity. 

This drug blocks binding of androgens to tissue-muscle cells and prevents biological action of androgens, inclnding in pancreatic tumor cells. 

The protein anabolic actions of androgens on bone and skeletal muscle are responsible for the larger stature of males than females. Androgens induce some degree of anabolism in other tissues, including bone marrow, liver, kidney, and heart. They also have several other actions, not necessarily associated with maleness, such as lymphoid tissue regression during puberty. 

---