Sermorelin is also produced under the chemical name GRF 1-29, though this label is not nearly as common. Sermorelin is a growth hormone analogue that is made up of a 29 amino acid chain. This is a 1-29 fragment of the endogenous growth hormone releasing hormone or GHRH peptide. This can be used as a means of checking growth hormone secretions in animal subjects.
This is the shortest GRF fragment that can show full biological activity within the body. The chemical can easily be replicated for use in research settings. Applying semorelin to animal tissues has been found to directly stimulate the pituitary gland, causing it to release growth hormone. This will increase plasma growth hormone, which is used in developing animals, to encourage tissue growth and development.
Effects of Long-Term Administration
To address chronic GHRH administration will require an administration of growth hormone to ensure that the pituitary content is not depleted.
To test the proper administrations for this technique, prepubertal female rats were given administrations of GHRH as well as somatostatin for 19 days.
In a complimentary study female rats were given GHRH using slow release pellets or injections for 21 days along with somatostatin.
During these applications body weight significantly increased, particularly during the highest daily administration of GHRH. The hypothalamic administrations of somatostatin decreased when these chemicals were administered alone, but this did not appear to affect the nature of the treatment.
This research suggests that the chronic effects of these peptides on the hypothalamus can increase growth hormone plasma levels. However, GHRH alone does not appear to be enough to raise body weight without the assistance of somatostain, to relieve chronic symptoms in animals.
Summary of Actions
Hormones affected by intravenous sermorelin appear to react to specific diagnosis of growth hormone deficiencies.
In adult animals it appears as though intravenous arginine and sermorelin creates responses when there is a growth hormone deficiency, but this cannot exclude deficiencies that are a result of hypothalamic deficits.
Some data suggests that preputeral animals that have an idiopathic growth hormone deficiency may benefit from constant applications of semorelin for up to 36 months. This includes those that appear to have delayed height and weight responses. The full effects this could have on full grown adults have yet to be determined.
Somrelin is generally well tolerated and can be used at a provocative test hormone in conjunction with other conventional tests.
Long-Acting Alkylated Substitutes
Analogs of GHRH that involve derivatization of alkyl substitutes at the N-terminus with or without the alkylaton of the amino acids in the peptide chain can be synthesized with a solid-base methodology for stimulating growth hormone.
Combining modification reported superactive analog modifications should not alter the potency of the chemicals.
All chemicals used in these comparisons are long-acting peptides when compared to GRF-29. Specifically, triisopropylated analogs have the longest potency with in vitro potencies of these analogues in vivo showing slight increases in respect to the original GRF-29 figures.
The increases that were observed in ‘in vivo’ potencies are likely occurring because of the enhanced resistance in the animal to the enzymatic degradation that follows the alkylation of these chemicals. This may also be due to another pharmacokinetic effect that is caused by the increase in lipophilicity of analogues.
Measuring the natural amount of semorelin that is present in an animal’s body is thought to be an effective method for diagnosing growth disorders, particularly those that stem from a lack of growth hormone stimulation in the body.
Further understanding how this natural process works will help scientists determine a pharmaceutical application for semorelin, perhaps as a way of addressing and correcting these growth disorders in animals that are still developing, to prevent stunted growth and other negative side effects.