physio- growth hormone

growth hormone inhibiting hormone (GHIH)

growth hormone releasing hormone (GHRH)

what are the 2 hormones related with GH that are released from the hypothalamus- 1 and 2 in this diagram?

growth hormone (GH)

what is the hormone that is released from the anterior pituitary- 3 in this diagram?

20 minutes

what is the half life of GH?

NON tropic- because it directly stimulates other tissues rather than another endocrine gland

is GH tropic or non tropic?

anterior pituitary (adenohypophysis)

what does the synthesis, storage, and secretion of GH?

the hypothalamus (with GHRH and GHIH)

what regulates the release of GH from the anterior pituitary?

with GHBP- growth hormone binding protein

how is GH transported through the plasma?

growth hormone binding protein- binds GH to transport it through blood plasma

what is GHBP and what does it do?

somatotropin

what is another name for GH?

hydrosoluble

is GH hydrosoluble or liposoluble?

by the kidneys

how is GH eliminated?

1. promoting cell differentiation

2. promoting protein synthesis

what are the 2 ways that GH regulates growth?

regulate growth

what is the main role of GH?

no, it is released in higher amounts during puberty and during the nighttime

is GH released equally throughout the life?

cell membrane (because it is hydrosoluble)

where is the receptor for GH located?

causes an intracellular cascade and phosphorylation, which ultimately triggers protein synthesis

what happens when GH binds to its receptor ?

metabolism

what is the direct effect of GH?

growth

if the direct effect of GH is metabolism, what is the indirect effect?

increases glycemia by:

- decreasing use of glucose

- increasing gluconeogenesis

- increasing glycogenolysis (catabolism)

what is the effect of GH on carbohydrates?

because it increases glycemia (amount of glucose), which stimulates the production of insulin. however, it does not allow insulin to act, producing resistance

why can GH have a diabetogenic effect?

once released from the anterior pituitary, it travels through the blood, bound to GHBP to its target cell. the receptor is on the cell membrane of the target cell. GH, once bound to the receptor, induces a cascade inside of the cell, which causes phosphorylation, ultimately triggering protein synthesis

what is the mechanism of action of GH?

increase

GH--->______ glycemia (increase or decrease)

decrease

GH--->______ glucose use (increase or decrease)

increase

GH--->______ gluconeogenesis (increase or decrease)

increase

GH--->______ glycogenolysis (increase or decrease)

increases free fatty acids by increasing lipolysis

increases free fatty acid conversion to acetyl CoA to produce energy

what effect does GH have on lipids?

increase

GH--->______ free fatty acids (increase or decrease)

increase

GH--->______ lipolysis (increase or decrease)

decreases

GH--->______ lipid synthesis (increase or decrease)

ketogenic

because GH increases FFA oxidation and mobilizes fat tissue, it is considered to have a ________ effect

it mobilizes fat tissue (allows its use for energy)

GH has a ketogenic effect. what does this mean?

increases proteins in body by:

- increasing amino acid transport

- increasing protein synthesis

- decreasing catabolism of proteins

what is the effect of GH on proteins?

anabolic- turns amino acids into proteins

GH has a _______ (anabolic or catabolic) effect on proteins

catabolic- breaks glycogen into glucose

GH has a _______ (anabolic or catabolic) effect on glycogen

increasing cell size

stimulating mitosis

promoting differentiation of stem cells

promoting proliferation

how does GH increase growth of tissues?

increases protein deposit in chondrocytes

increases speed of multiplication of cells

increases conversion of chondrocytes into osteogenic cells

how does GH effect the skeleton?

increases protein deposit in chondrocytes

increases speed of multiplication of cells

increases conversion of chondrocytes into osteogenic cells

how does GH promote bone growth?

increase in body mass and body tissues

what is the effect of GH reducing protein degradation and increasing protein synthesis?

during childhood, GH stimulates growth of ALL bodily tissue- organs, bones, etc

during adulthood, GH doesn't stimulate bone growth anymore

how does GH affect the body differently in childhood vs adulthood?

other substances that influence growth via external control of the cell cycle

what are growth factors and what do they do?

both

do growth factors act locally or do they go to other tissues via blood transport?

a type of growth factor that mediates the growth promoting actions of GH

what are somatomedins?

somatomedins

what is the major growth factor that is necessary for growth?

IGF-1 and IGF-2

what are the main types of somatomedins?

in the liver

where are somatomedins produced?

GH

what stimulates the production of somatomedins in the liver?

increase

GH---> _______ (increase or decrease) breast tissue development

increase

GH---> _______ (increase or decrease) milk production

increase

GH---> _______ (increase or decrease) immune response

increase

GH---> _______ (increase or decrease) erythropoeisis

increase

GH---> _______ (increase or decrease) glomerular filtration rate

increase

GH---> _______ (increase or decrease) salt retention

hyperglycemia- decreases secretion

hypoglycemia- increases secretion

high amount of amino acids- increases secretion

IGF-1- inhibits secretion

TRH- increases secretion

CRH- decreases secretion

high cortisol- increases secretion

other than GHIH and GHRH, what other factors can regulate the secretion of GH?

decrease

will hyperglycemia trigger an increase or decrease of GH?

increase

will hypoglycemia trigger an increase or decrease of GH?

increase

will high amount of amino acids trigger an increase or decrease of GH?

inhibits GH secretion

what is the affect of IGF-1 on GH secretion?

dwarfism, growth retardation

when there is not enough secretion of GH, what are the effects?

it reduces GH's response to stimuli

what effect does hypothyroidism have on GH?

decreases secretion of GH

what effect does Cushing's syndrome have on GH?

it decreases the secretion of ALL other anterior pituitary hormones

when there is a decrease of secretion of GH, how does this affect other hormones?

-diabetes

-gigantism (if it is before closure of epiphyseal plates)

-thick long bones and long membrane bones (if it is after closure of epiphyseal plates)

what are the effects of GH hypersecretion (too much secretion of GH)?

negative

does IGF-1 give positive or negative feedback to the anterior pituitary?