The involvement of mammalian target of rapamycin (mTOR) in lifespan control in invertebrates, calorie-restricted rodents, and extension of mouse lifespan by rapamycin have prompted speculation that diminished mTOR function may contribute to mammalian longevity in several settings. We show here that mTOR complex-1 (mTORC1) activity is indeed lower in liver, muscle, heart, and kidney tissue of Sn...

The correlation of physiological sensitivity to insulin ( vis-à-vis glycemic regulation) and longevity is extensively established, creating a justifiable gerontological interest on whether insulin sensitivity is causative, or even predictive, of some or all phenotypes of slowed senescence (including longevity). The growth hormone receptor/ binding protein gene-disrupted (GHR-KO) mouse is the mo...

The correlation of physiological sensitivity to insulin ( glycemic vis-à-vis regulation) and longevity is extensively established, creating a justifiable gerontological interest on whether insulin sensitivity is causative, or even predictive, of some or all phenotypes of slowed senescence (including longevity). The gene-disrupted growth hormone receptor/ binding protein (GHR-KO) mouse is the mo...

OBJECTIVE The GH/IGF-1 axis has important roles in growth and metabolism. GH and GH receptor (GHR) are active in the central nervous system (CNS) and are crucial in regulating several aspects of metabolism. In the hypothalamus, there is a high abundance of GH-responsive cells, but the role of GH signaling in hypothalamic neurons is unknown. Previous work has demonstrated that the Ghr gene is hi...

The human GH gene is 1.7 kilobase pairs (kb) in length and is composed of five exons and four introns. This gene is expressed in the pituitary gland and encodes a 22 kDa protein. In addition to this predominant (75%) form, 5-10% of pituitary GH is present as a 20 kDa protein that has an amino acid (aa) sequence identical to the 22 kDa form except for a 15 aa internal deletion of residues 32-46 ...

The goal of this study was to test whether the "loss of the complexity" hypothesis can be applied to compare the metabolic patterns of mouse models with known differences in metabolic and endocrine function as well as life span. Here, we compare the complexity of locomotor activity and metabolic patterns (energy expenditure, VO₂, and respiratory quotient) of the long-lived growth hormone recept...

Alleles of the growth hormone (GH) gene and GH receptor (GHR) gene were analyzed for association with juvenile body weight (HBWT), age at first egg (AFE), the hen-day rate of egg production (HDR), egg specific gravity (SPG), and egg weight (EWT) in a strain of White Leghorns. The particular strain segregated at near equal frequencies for two GH alleles defined by differences at three restrictio...

Previous studies have demonstrated that the p.Lys232Ala substitution in the acylCoA: diacylglycerol acyltransferase (DGAT1) gene and the p.Phe279Tyr mutation in the growth hormone receptor (GHR) gene are the causative quantitative trait loci underlying milk yield and composition on BTA14 and BTA20 respectively. To examine their applications in the genetic improvement of Chinese dairy cattle pro...

The objective of this study was to assess the effects of food deprivation and exogenous cortisol administration on somatic growth of channel catfish, Ictalurus punctatus, and examine the resultant changes in circulating insulin-like growth factor-I (IGF-I) concentrations and growth hormone receptor (GHR) gene expression. Integral to this objective, we report the isolation, sequence, and charact...

Excessive GHRH stimulation leads to somatotrope hyperplasia and, ultimately, pituitary adenoma formation in the metallothionein promoter-driven human GHRH (hGHRH) transgenic mouse. This pituitary phenotype is similar to that observed in humans with ectopic production of GHRH. In both mice and man, GHRH hyperstimulation also results in dramatic increases in circulating GH and IGF-I. To determine...