Gonadorelin

Gonadorelin (synonyms: gonadoliberin, gonadotrophin-rileasing-hormone, in abbreviated form GNRG) is a natural hormone which causes strengthening of secretion of gonadotrophins: FSG (a follicle - the stimulating hormone) and LH (lyuteniziruyushchy hormone) which in turn increase testosterone secretion. Now there were synthetic analogs of gonadorelin which began to be applied in bodybuilding.

Actually represents replacement of horionichesky gonadotrophin, at the same time without having before it particular advantages in bodybuilding. In medicine gonadoliberin is applied to treatment of endometrioses, fibroses of a uterus, infertility and a prostate cancer.

Synthetic analogs (medicines): triptorelin, buserelin, leyprorelina acetate, leyprolid, goserelin, nafarelin, gistrelin.

Physiology

The hypothalamus releases several hormonal substances, one of which gonadoliberin which is decapeptide on structure. Gonadorelin in turn influences receptors of a forward share of a hypophysis, forcing it to release gonadotrophins (lyuteiniziruyushchy hormone and a follicle - the stimulating hormone) which in turn regulate release of male sex hormones (androgens) testicles. You can try Testalamin.

Process of secretion of these hormones has the pulsing nature with a frequency about 1-2 times an hour. This secretion is regulated on a feedback mechanism by other hormonal substances. Such hormones as estrogen, testosterone and anabolic steroids suppress an axis hypothalamuses-hypophyses-testicles therefore products of own testosterone decrease.

Pharmacology

The synthetic form of gonadoliberin also stimulates secretion of LG and FSG of a forward share of a hypophysis that, in turn, leads to stimulation of maturing of follicles and an ovulation at women, a spermatogenesis and secretion of testosterone at men.

Gonadorelin is badly absorbed from a GIT therefore it is entered with injections, or in the form of intranasal spray. After an injection the half-life period makes about 10-40 minutes. It is hydrolyzed (breaks up) in plasma of blood and it is removed with urine in the form of inactive metabolites.

Effects of gonadoliberin will depend on the scheme of application:

The pulsing scheme (faltering) will lead to increase in level of testosterone.

The continuous course results in boomerang effect. It occurs due to bystry development of tolerance (sensitivity of receptors of a hypophysis decreases). On it this scheme is used even in compulsory treatment of pedophiles, for the purpose of suppression of sexual function and a libido. Actually, it is a way of chemical castration.

Medicines of gonadoliberin

• goserelin (Zoladex)
• leuprorelin (Prostap)
• triptorelin (Decapeptyl, Gonapeptyl Depot)
• buserelin (Suprecur, Suprefact)
• nafarelin

Use in bodybuilding

It is often offered to apply gonadoliberin in bodybuilding as the PCT component after a course of anabolic steroids according to the scheme within 2 weeks, instead of Gonadotropinum, with introduction each 1,5 or 3 hours within 2-4 weeks. However from the pharmacological point of view this scheme is wrong as gonadoliberin can cause long and deep suppression of own Testosteron-Depotum after cancellation.

In medicine gonadoliberin (gonadorelina an acetate) use at the disturbances of genesial function bound to deficiency of gonadoliberin. The drug is administered i.v. by means of the special infusional pump in the pulsed operation imitating physiological secretion, 2,5 mkg each 60 — 90 min. (Hayes et al., 1998).

By means of gonadorelin it is possible to achieve body height of testicles, normal secretion of sex hormones and a spermatogenesis from men. However the method is rather expensive and demands constant wearing of the infusional pump. Besides gonadoliberin FDA for treatment of male sterility isn't approved. Therefore usually preference is given to gonadotrophic hormones.

Side effects

In the clinic and pharml reference book of P. P. Denisenko it is reported about the following side effects of gonadorelin:

• Suppression of an axis a hypothalamus hypophysis testicles at the wrong scheme of application
• Inflows and decrease in a potentiality
• Swelling and morbidity of chest glands
• Headache
• Bone pains
• Nausea, diarrhea
• Allergic reactions