Hexarelin and Cardiac Functionalities
However, Ghrelin is unstable. Therefore its half-life, potency and the effectiveness is slightly hampered. Growth hormone secretagogue hexarelin is a biochemically stable compound. It is a more potent hexapeptide that can be administered orally to test subjects as an alternative to the Ghrelin. It exerts its effects longer and more effectively than the original peptide. Moreover, hexarelin uses GHSR 1 a receptor just like the natural biological system, thereby its effects is beneficial and long lasting. The cardiac functionality of hexarelin is mediated by the receptors and the activation of the CD36 receptors.
Hexarelin and Apoptosis
According to research carried out by scientists, neonatal rats cardiomyocytes were subjected to hexarelin dosage. The levels of angiotensin II ere reduced and this accentuated DNA fragmentation and apoptosis of the myocytes. In addition, the viability of the cardiomyocytes improved greatly and this helped in the reduction of cell death. Hexarelin treatment has shown the ability to inhibit the effects of doxorubicin -induced apoptosis.
Hexarelin and Cardioprotective Effects
Hexarelin is one of the most studied ghrelin mimetics and is one of the latest potent growth hormone releasing compounds. The peptide is seen to have an effect on prolactin and cortisol release. Hexarelin is more potent in the production of growth hormone from the pituitary gland. The effect of prolactin and cortisol release depends on the concentration of the hormone in a biological system. All the ghrelin mimetic have unique properties that bring about the release of growth hormone from the pituitary gland.
It is imperative to note that the growth hormone is released alongside somatostatin from the somatotrophs and when the production of somatostatin is at its peak, the production of the growth hormone is at its lowest. Studies revealed that hexarelin reduces the extent of cerebral cortex injury and hippocampus after a hypoxia-ischemia. This was a study conducted on neonatal rats. The study showed that ghrelin may have a role in this as well.
Research showed that the peptide has cardioprotective effects and the GHS-R messenger RNA is expressed in the cardiomyocytes or the cells of the heart when hexarelin was administered. This showed that hexarelin abates the cells of the heart from ANG-2 induced cell death. This is via the inhibition of the caspase-3 activity and the expression of Bax through an increase of Bcl-2 which is usually reduced by the presence of ANG 2
Effects of Hexarelin on Ischemia Reperfusion Injury
The hearts of neonatal mice were subjected to a half an hour then two-hour reperfusion. Hexarelin was seen to reduce the size of the infarction and this was determined by triphenyltetrazolium chloride staining. The peptide provided protection and reduced the activity of protein kinase C inhibitor chelerythrine. The treatment of the peptide was seen to inhibit cardiomyocytes apoptosis. It preserved the electrical properties of the cells and promoted cellular survival through the modification of the nitrogen activated protein kinase pathways. In addition, hexarelin induced a positive inotropic effect on ischemic cardiomyocytes.
Hexarelin and Cardiac Fibrosis
Hexarelin administration on hypertensive and spontaneous mice for 40 days showed a major reduction in cardiac fibrosis. This was seen through the reduction of myocardial collagen deposition and the interstitial collagen thereby reducing myocardial hydroxyproline and reducing the levels of collagen I and III, messenger RNA and the expression of the proteins. In addition, hexarelin administration was seen to increase the concentration and level of metalloproteinase -2 and -9 activities and reduced the myocardial messenger ribonucleic acid expression on the tissue. The treatment of cultured fibroblasts with hexarelin was seen to inhibit the activities of angiotensin II proliferation, transformation of transforming factor-beta induced DNA synthesis, collagen synthesis and reduction in the levels of the angiotensin III –mediated up-regulation of the TGF-beta release and expression.
Anti-atherosclerotic activity of hexarelin can be elucidated on the adult Sprague-Dawley rat. These rats were subjected to the peptide administration and formation of the atherosclerotic plaques and neointima were reduced effectively. In addition, the peptide reversed the serum low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio. On the contrary, there was an increased level of serum nitric oxide and the expression of messenger RNA of the enzyme nitric synthase, CD 36 and growth hormone secretagogues on the subjects. In addition, the treatment of hexarelin decreased the level of tritiated thymidine incorporated on the cultured vascular smooth muscle cells. The peptide reduced the formation of calcium sedimentation on the aortic wall.
Effects of Hexarelin on Cardiac Receptors
The cardiovascular activities of hexarelin can be attributed largely to growth hormone. This mainly occurs through the activation of the cardiac receptors. Earlier studies revealed that the peptide receptors were not shared by the growth hormone releasing hormone. This indicated that they were not mediated by the level of growth hormone. The peptide exerted its effects on the LVEF and it helped in preventing cardiac damage.
Principle of Action
Studies revealed that some hexarelin side effects include an increase in mitosis, increase in bone mineral density, meiosis, connective tissue, improved skin elasticity, and fat loss. The benefits of the peptide include an increase in lean body mass, fat reduction, anti-ageing properties and an increase in bone density. However, hexarelin side effects include an increase in prolactin levels, decreased libido, possible gynecomastia, increased cortisol levels.
Hexarelin is delivered as dried powder just like any other growth hormone hexapeptide. It should be stored in a cool dry place like a refrigerator. When reconstituting it for injection into test subjects, bacteriostatic water should be used. Research showed that a combined vial of hexarelin and another growth hormone releasing peptide produces enhanced potency, effectiveness and efficacy.