✳Growth hormone ( GH )
-------------------------------------------
🔘Growth Hormone (GH)
Human growth hormone (also called somatotropin) is
a protein of 191 amino acids.
🔘The GH secreting cells are stimulated to synthesize
and release GH by the intermittent arrival of growth
hormone releasing hormone (GHRH) from the
hypothalamus.
🔘 Direct effects are the result of growth hormone
binding its receptor on target cells. Fat cells
(adipocytes), for example, have growth hormone
receptors, and growth hormone stimulates them
to break down triglyceride and suppresses their
ability to take up and accumulate circulating
lipids
🔘Indirect effects are mediated primarily by an
insulin-like growth factor-I (IGF-I), a hormone
that is secreted from the liver and other tissues in
response to growth hormone. A majority of the
growth promoting effects of growth hormone is
actually due to IGF-I acting on its target cells ( see to the fig.)
🔴Pathophysiology
-------------------------------
✳ In childhood:
🔵hyposecretion of GH in children led to dwarfism.
🔘Dwarfism can also result from an inability to
respond to GH
🔼This can result from inheriting two mutant genes
encoding the receptors for:
– GHRH
– GH
🔘Growth hormone deficiency symptoms:
Symptoms of
GH deficiency in children include the following:
🔼 Short stature
🔼 Lowgrowthvelocity (speed)for age andpubertal stage
🔼 Increased amount of fat around the waist
🔼 The child may look younger than other children his
or her age
🔼Delayed tooth development
🔼Delayed onset of puberty.
Symptoms of GH deficiency in adults include the
following:
– Low energy
– Decreased strength and exercise tolerance
– Decreased muscle mass
– Weight gain, especially around the waist
– Feelings of anxiety, depression, or sadness
causing a change in social behavior.
🔵Hypersecretion of GH in children
🔘Hypersecretion leads to gigantism
🔘Gigantism is the result of excessive growth
hormone secretion that begins in young children
or adolescents. It is a very rare disorder, usually
resulting from a tumor of somatotropes.
🔵hypersecretion ofGH in adult:
🔼Hypersecretion of GH in adult led to acromegaly
🔘 Acromegaly results from excessive secretion of
growth hormone in adults, usually the result of
benign pituitary tumors. The onset of this disorder
is typically insidious, occurring over several years.
Clinical signs of acromegaly include
🔼 overgrowth of extremities
🔼soft-tissue swelling abnormalities
in jaw structure and cardiac disease.
🔼The excessive growth hormone and IGF-I also lead to a number of metabolic derangements, including
hyperglycemia.
=======================
Dr. Haidar Al-mamari
=======================
https://news.1rj.ru/str/Biochemistrys
-------------------------------------------
🔘Growth Hormone (GH)
Human growth hormone (also called somatotropin) is
a protein of 191 amino acids.
🔘The GH secreting cells are stimulated to synthesize
and release GH by the intermittent arrival of growth
hormone releasing hormone (GHRH) from the
hypothalamus.
🔘 Direct effects are the result of growth hormone
binding its receptor on target cells. Fat cells
(adipocytes), for example, have growth hormone
receptors, and growth hormone stimulates them
to break down triglyceride and suppresses their
ability to take up and accumulate circulating
lipids
🔘Indirect effects are mediated primarily by an
insulin-like growth factor-I (IGF-I), a hormone
that is secreted from the liver and other tissues in
response to growth hormone. A majority of the
growth promoting effects of growth hormone is
actually due to IGF-I acting on its target cells ( see to the fig.)
🔴Pathophysiology
-------------------------------
✳ In childhood:
🔵hyposecretion of GH in children led to dwarfism.
🔘Dwarfism can also result from an inability to
respond to GH
🔼This can result from inheriting two mutant genes
encoding the receptors for:
– GHRH
– GH
🔘Growth hormone deficiency symptoms:
Symptoms of
GH deficiency in children include the following:
🔼 Short stature
🔼 Lowgrowthvelocity (speed)for age andpubertal stage
🔼 Increased amount of fat around the waist
🔼 The child may look younger than other children his
or her age
🔼Delayed tooth development
🔼Delayed onset of puberty.
Symptoms of GH deficiency in adults include the
following:
– Low energy
– Decreased strength and exercise tolerance
– Decreased muscle mass
– Weight gain, especially around the waist
– Feelings of anxiety, depression, or sadness
causing a change in social behavior.
🔵Hypersecretion of GH in children
🔘Hypersecretion leads to gigantism
🔘Gigantism is the result of excessive growth
hormone secretion that begins in young children
or adolescents. It is a very rare disorder, usually
resulting from a tumor of somatotropes.
🔵hypersecretion ofGH in adult:
🔼Hypersecretion of GH in adult led to acromegaly
🔘 Acromegaly results from excessive secretion of
growth hormone in adults, usually the result of
benign pituitary tumors. The onset of this disorder
is typically insidious, occurring over several years.
Clinical signs of acromegaly include
🔼 overgrowth of extremities
🔼soft-tissue swelling abnormalities
in jaw structure and cardiac disease.
🔼The excessive growth hormone and IGF-I also lead to a number of metabolic derangements, including
hyperglycemia.
=======================
Dr. Haidar Al-mamari
=======================
https://news.1rj.ru/str/Biochemistrys
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