Effect of acute and regular exercise on growth hormone secretagogue receptor-1a expression in human lymphocytes, T cell subpopulation and monocytes

Effect of acute and regular exercise on growth hormone secretagogue receptor-1a expression in human lymphocytes, T cell subpopulation and monocyte

Ghrelin axis genes, peptides and receptors : recent findings and future challenges

The ghrelin axis consists of the gene products of the ghrelin gene (GHRL), and their receptors, including the classical ghrelin receptor GHSR. While it is well-known that the ghrelin gene encodes the 28 amino acid ghrelin peptide hormone, it is now also clear that the locus encodes a range of other bioactive molecules, including novel peptides and non-coding RNAs. For many of these molecules, the physiological functions and cognate receptor(s) remain to be determined. Emerging research techniques, including proteogenomics, are likely to reveal further ghrelin axis-derived molecules. Studies of the role of ghrelin axis genes, peptides and receptors, therefore, promises to be a fruitful area of basic and clinical research in years to come

The Presence of Growth Hormone Secretagogue Receptor (ghrelin receptor) in Metabolic Tissues of Beef Cattle with Differences in Composition of Gain

Beef steers (n = 72) of similar age, weight (651 ± 3.1 lb), and genetic (Angus crossbred) background were used to determine the effects of growing diet composition (high‐forage vs. high‐concentrate) on the abundance of growth hormone secretagogue receptor (GHS‐R or ghrelin receptor) in metabolically important tissues of beef cattle. At trial initiation (d 0), 8 steers were harvested for initial carcass composition. The remaining 64 steers were allotted, by weight, to pen and treatment was assigned randomly. Treatments were 1) a high‐forage diet fed during the growing period (116 d) followed by a high‐concentrate diet during the finishing period (117‐209 d; GRW‐FNSH) or 2) a high‐concentrate diet fed for the duration of the trial (0‐209 d; FNSH‐FNSH). Steers were allowed ad libitum consumption regardless of dietary treatment. Eight steers per treatment were harvested on d 88, 116, 165, and 209. Immediately following harvest, liver, muscle (sternomandibularis), and subcutaneous adipose tissue samples were collected from each steer and immersed in liquid nitrogen. Longissimus dorsi samples were collected following a 48 h chill to establish a preliminary analysis of GHS‐R abundance within an economically important muscle tissue. Protein separation and quantification was determined using SDSPAGE and Western blotting techniques. Protein abundance was detected using the LI‐COR® system and standardized to β‐Actin. Protein abundance data were analyzed statistically using the GLM procedure of SAS comparing diet, harvest date, and their interaction. Protein abundance of GHS‐R in longissimus dorsi tissue fluctuated relative to serial harvest date (P \u3c 0.001), and was highest on d 88 in both treatment groups. The FNSH‐FNSH steers had increased abundance of GHS‐R in longissimus dorsi on d 88 and 116 compared with the GRW‐FNSH steers. A dietary treatment by serial harvest day interaction (P \u3c 0.05) occurred for protein abundance of GHS‐R in subcutaneous adipose tissue. Abundance of GHS‐R in subcutaneous adipose tissue of the GRW‐FNSH was greatest on d 88, whereas abundance for the FNSHFNSH treatment was greatest at the end of the finishing period (d 209). An interaction of dietary treatment and serial harvest day resulted (P \u3c 0.05) for GHS‐R abundance in liver tissue. The GRW‐FNSH steers had increased liver GHS‐R abundance following realimentation compared with the FNSH‐FNSH steers which were on a continuous plane of nutrition. Protein abundance for liver GHS‐R in both dietary treatments increased quadraticly (P \u3c 0.001) throughout the feeding period. The GHS‐R was not detected in sternomandibularis tissue. Overall liver GHS‐R abundance increased in both dietary treatments following realimentation which is inconsistent with our hypothesis. Increased GHS‐R abundance in various tissues of beef cattle while ghrelin concentrations are high and excess fat deposition is occurring warrants further investigation

Ghrelin in Female and Male Reproduction

Ghrelin and one of its functional receptors, GHS-R1a (Growth Hormone Secretagogue Receptor 1a), were firstly studied about 15 years. Ghrelin is a multifunctional peptide hormone that affects several biological functions including food intake, glucose release, cell proliferation… Ghrelin and GHS-R1a are expressed in key cells of both male and female reproductive organs in several species including fishes, birds, and mammals suggesting a well-conserved signal through the evolution and a role in the control of fertility. Ghrelin could be a component of the complex series of nutrient sensors such as adipokines, and nuclear receptors, which regulate reproduction in function of the energy stores. The objective of this paper was to report the available information about the ghrelin system and its role at the level of the hypothalamic-pituitary-gonadal axis in both sexes

Obesity as the Sequel of Childhood Stunting: Ghrelin and GHSR Gene Polymorphism Explained

Stunting or short stature in children is a significant nutritional problem in developing and underdeveloped countries. Stunting during childhood might affect brain development and impair development cognitive function. Additionally, this condition associated with the increased risk for obesity during adulthood. Several studies have shown that the increment risk of obesity and overweight in children with a short stature was due to their metabolic efficiency. Children with stunting have lower resting energy expenditure compared to non stunting children. Additionally, stunted children has higher respiratory quotient and carbohydrate oxidation but lower fat oxidation compared to non-stunting children. These results might explain why stunted children easily become obese, which is due to lower fat oxidation and leading to tendency to store fat.This review discussed the current status on studies in the nutrigenetic aspects of the relationship between stunting in the childhood and obesity in adulthood. I hypothesized that stunted children are more likely to become obese in their later life because they have lower metabolic rate and higher tendency of fat storage. There are several candidate genes and pathway involved in obesity and I suspected that ghrelin and its receptor growth hormone secretague receptor (GHSR) were responsible

The Physiological potentials of Ghrelin in enhancing Feed intake in Livestock

Ghrelin is an orexigenic protein with a unique lipid chain modification and is known to be an important gut-brain signal for appetite control and energy balance. It is neuroendocrine hormone secreted mainly by the oxyntic cells of gastric fundus and travels to the brain. There it interacts with both the hypothalamus (the brain’s physiological eating center) and the brain’s pleasure centers to arouse hunger. The ghrelin receptor, growth-hormone secretagogue receptor type 1a, is able to bind acylated ghrelin. The first recognised effect of ghrelin was the induction of growth hormone release from the somatotroph cells of the anterior pituitary. It is also expressed in the pancreatic islets, hypothalamus, pituitary and several tissues in the periphery. The aim of this review is to see some of the effects of ghrelin on feeding behaviour in selected livestock specie

Ghrelin receptor (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

The ghrelin receptor (nomenclature as agreed by the NC-IUPHAR Subcommittee for the Ghrelin receptor [18]) is activated by a 28 amino-acid peptide originally isolated from rat stomach, where it is cleaved from a 117 amino-acid precursor (GHRL, Q9UBU3). The human gene encoding the precursor peptide has 83% sequence homology to rat prepro-ghrelin, although the mature peptides from rat and human differ by only two amino acids [70]. Alternative splicing results in the formation of a second peptide, [des-Gln14]ghrelin with equipotent biological activity [48]. A unique post-translational modification (octanoylation of Ser3, catalysed by ghrelin Ο-acyltransferase (MBOAT4, Q96T53) [127] occurs in both peptides, essential for full activity in binding to ghrelin receptors in the hypothalamus and pituitary, and for the release of growth hormone from the pituitary [56]. Structure activity studies showed the first five N-terminal amino acids to be the minimum required for binding [4], and receptor mutagenesis has indicated overlap of the ghrelin binding site with those for small molecule agonists and allosteric modulators of ghrelin function [43]. In cell systems, the ghrelin receptor is constitutively active [44], but this is abolished by a naturally occurring mutation (A204E) that results in decreased cell surface receptor expression and is associated with familial short stature [88]