Growth hormone action mechanism

Basic knowledge about GH

Overview of growth hormone

Growth hormone release and regulation Growth hormone secretion
Stimulating factors for growth hormone secretion Inhibitory factors of growth hormone secretion Physiological effects of growth hormone

Growth hormone overview

Structure A single chain containing 191 amino acid residues, a protein linked by two disulfide bonds.

Secretion secretion of eosinophils in the anterior pituitary

Molecular weight 22KD

Natural conformation of growth hormone

–SCIENCE, 1992; 255 306-312

The first growth hormone crystal diffraction photo shows

Growth hormone overview

Growth hormone secretion regulation

Advanced nerve center

Hypothalamus

GHRH(+) SRIF(-)

Anterior pituitary

Growth hormone (also known as growth hormone)

Direct action

gonad

Growth hormone release and regulation

Controlled by two neurohormones

Growth hormone releasing hormone (GHRH)

  1. Growth hormone releasing hormone inhibitor (SRIF)

Physiological growth hormone secretion pattern

Interval 3~5 hours, about 8 pulsesday, highest at night

Growth hormone secretion

Features pulsed secretion;

Frequency secreted once every 3-4 hours;

Peak The amount of secretion in one hour after sleep is more than half of the total amount of the day;

Growth hormone secretion at different stages of puberty

Physiological effects of growth hormone (1)

GH promotes growth A GH stimulates chondrocytes to produce IGF-1 locally, promoting cartilage thinning
The cells proliferate, thereby promoting bone growth and increasing bone length. B After osteophyte fusion, GH can directly stimulate bone metabolism of osteoblasts, and
It still plays an important role in maintaining bone mineral content and bone density. C GH synergistic hormones and procalcitonins work together to reshape bone,
It induces vitamin D activation by IGF-1.

Physiological effects of growth hormone (2)

GH regulating substance metabolism

A GH promotes protein synthesis, promotes the transport of amino acids into cells, increases intracellular RNA synthesis, and exhibits a positive nitrogen balance.

B GH has a degrading effect on fat. It has an important regulatory effect on the fat-melting rate of fat cells. Because it induces beta adrenergic receptors on the fat cell membrane, it leads to a fat-melting effect.

C GH is complex for sugar metabolism. It can reduce the sensitivity of cells to insulin, and can also reduce the utilization of glucose by peripheral tissues, and long-term use can cause elevated blood sugar.

D GH plays an important role in water and mineral metabolism. GH can retain potassium and phosphate in cells, promote renal tubular absorption, activate the renin-angiotensin-aldosterone system, and cause water and sodium retention.

Physiological effects of growth hormone (3)

Other GH has anti-aging and promotes brain function. And enhance heart function,
The research on immune function, improving muscle strength and promoting sperm formation and ovulation is remarkable.

Stimulating factors for growth hormone secretion

Deep sleep
Stress state
Drugs insulin (induced hypoglycemia), clonidine, arginine, etc.

Inhibitory factors of growth hormone secretion

Rapid eye movement sleep psychological factors
Central nervous system tumor
Drugs glucocorticoids, etc. Hypothyroidism

Regulation of GH secretion by GH-IGF-I axis

Growth hormone action mechanism

liver

Growth hormone promotes linear growth of bone by acting directly on bone or through IGF-1 mediated action on bone. The anti-GH antibody hinders the binding of GH to the receptor, thereby inhibiting the production of IGF-1, thereby promoting its growth promoting effect.

History of growth hormone development

1956 Separation and purification of GH from corpse pituitary

1958-1985 At least 8,000 children in the United States receive this GH treatment

1985 Reported a fatal degenerative neurological disease after GH treatment

(Creutzfeldt-Jakob disease) disabled

1985 In vitro recombinant human growth hormone synthesis succeeded

A large number of clinical applications of rhGH are possible

1985 – More than 200,000 patients receive treatment

FDA approved genotropin growth hormone indications

1985 Child Growth Hormone Deficiency (GHD) 1993 Chronic Renal Insufficiency Before Renal Transplantation 1996 HIV Infectious Failure Syndrome 1996 Turner Syndrome

1997 Adult GHD

2001 Small for gestational age (SGA) 2002 Prader-Willi syndrome 2003 Idiopathic short stature (ISS)

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