Neuroendocrine 2 Flashcards
hGH is produced by what cells?
somatotropic cells
What is hGH?
Stimulated by growth hormone-releasing hormone (GHrH) of hypothalamus
hGH stimulates most cells
Encourage the use of fats for fuel
Promote protein synthesis
Effects are mediated indirectly by somatomedins (polypeptide hormones whose concentrations are largely governed by growth hormone secretion)
hGH augments transport of amino acids (AA’s) across the cell membrane – Up-regulation
^ AA’s = ^ Raw intracellular material for protein synthesis
What are the metabolic effects of hGH?
hGH directly augments ribosomal RNA translation
Occurs in cytoplasm
Increased protein synthesis
Occurs regardless of intracellular AA concentration
What is the Human growth hormone – From DNA to trait?
Prolonged periods (24-48 hours) - hGH directly stimulates transcription of DNA in the nucleus
Dependent on sufficient: Energy, amino acids and vitamins
Considered most important somatotrophic (i.e. promotes growth) effect of hGH
What is the process for making traits?
DNA
Transcription
Translation
Protein synthesis
Trait
Is Human growth hormone considered a protein sparer?
Human growth hormone is considered a protein sparer - Decreased catabolism of protein & AA’s
hGH directly decreases protein degradation
Effect of hGH-stimulated lipolysis
True or false. Human growth hormone enhances lipid utilisation
True
True or false. Lipid metabolism increases in lean body mass (LBM)
True
What are the Human growth hormone’s effects on the metabolism of carbohydrate (glucose)?
Increased insulin secretion
Increased glucose uptake in tissues via IGF
Increased hepatic gluconeogenesis
Production of glucose from non-carbohydrate sources | Lipids
Human growth hormone stimulates…
gluconeogenesis
Glucose produced from free fatty acids – Lipolysis of adipose tissue
Blood glucose is increased
What is the negative feedback response to elevated glucose?
Insulin release
Counteracted by hGH
Insulin growth factor (IGF) released from where to where?
Liver into the blood
