GHRP-2 is studied in a variety of applications which largely focus on its ability to trigger a hormone response. Researchers hope to understand what other processes are affected by this application, to further understand how this chemical may be applied in a pharmaceutical setting.
Induction of Adiposity in Rodents
The discovery of the ghrelin peptides or GHS receptors yielded a surprising result in the principal sites of ghrelin synthesis, which appears to be in the stomach rather than the hypothalamus.
Ghrelin is likely to have an effect in regulating the pituitary hormone secretion along with somatostatin and hormone GHS receptors that have been identified on the hypothalamic neurons as well as the brainstem.
Aside from the potential of this peptide’s paracrine effects ghrelin may also offer an endocrine link between the pituitary, hypothalamus and stomach. This suggests an involvement in the regulation of the body’s energy levels.
This indicates that peripheral daily administrations of ghrelin to animal test subjects can lead to weight gain by reducing the utilization of fat. This is particularly well showcased in mice and rats.
The interacerebroventricular administration of ghrelin has been demonstrated as a means of an increase in food intake as well as body weight, though these reactions are dependent on regular administrations of the chemical. These concentrations are further increased by fasting or refeeding the oral glucose administration, though water ingestion does not appear to have an effect on the animal’s body. This research proposes that ghrelin can assist with regulating secretions of hormone as well as signaling the hypothalamus to increase metabolic efficiencies.
Addressing Burn Injury-Induced MAFbx and MuRF-1 Expression
Thermal injuries will cause hypermetabolism, wasting of skeletal muscle and loss of weight in test subjects, like mice. Studies have indicated that ghrelin injections can increase hormone releases and food intake to inhibit these symptoms.
Mouse test subjects were given a low molecular weight when administered a longer and stable acting peptide that combat the catabolic responses that are triggered by a thermal injury.
During these conditions researchers noted the responses to hexapeptide, ghrelin and GHRP-2. Specifically, researchers traced the expression of these peptides on E3 ubiquitin ligases on the breakdown of protein in the muscle tissue of rodent test subjects.
A slow release of GHRP-2 was applied via a minipump for 24 hours after the thermal injury was induced. This increased the mRNA expressions of IL-6 in the animal’s ubiquitin ligases, MAFbx and MuRF-1 in the skeletal muscles.
Burn induced injuries and the breakdown of myofibrillar proteins in EDL muscles can be attenuated in rats, by applying GHRP-2. This research implies that catabolic responses that result from thermal injuries may be improved with GHRP-2.
Effects on Growth Performance in Swine
GHRP-2 effects on hormone releases were examined in swine of the text subjects, to better understand these effects.
Single intravenous applications of GHRP-2 were applied in 100, 30, 10 or 2 ug/kg doses in castrated cross-bred male swine to stimulate the release of hormone with a return baseline of 120. The hormone was dose dependent.
Peak concentrations of hormone appeared around 180 minutes after GHRP-2 was applied and decreased about 6 hours after the injection. These reactions continued to stimulate hormone for the 30 days of the experiment; these releases were higher than the swine treated with saline.
Chronic administration of GHRP-2 increased the gain each animal saw daily, throughout the treatment period by 22.35 percent compared to the saline control group, but the daily feed intake of the swine was not increased by these applications. This indicates that GHRP-2 can stimulate hormone to enhance the growth performance of these animals.