Growth Hormone Overview

Growth hormone (GH) is a protein produced by the anterior pituitary gland, specifically by cells called somatotropes. It plays a crucial role in body growth and development by increasing cell size and promoting cell division.

GH influences protein metabolism by increasing amino acid transport into cells, promoting RNA translation and DNA transcription, and decreasing protein breakdown. It also indirectly promotes protein synthesis by stimulating insulin release from the pancreas.

GH mobilizes stored fats from adipose tissue, providing energy to cells and sparing proteins. When GH levels are abnormally high, excess acetoacetic acid is released from the liver, leading to ketosis.

GH primarily conserves glucose by decreasing its usage for energy production in cells. It also promotes glycogen storage and reduces glucose uptake by cells, leading to a diabetic-like effect.

GH-binding proteins (GHBPs) are transport molecules that carry GH in the bloodstream. These proteins are essential for transporting and delivering GH to its target cells.

The half-life of GH in the blood is approximately 20 minutes. This means that it takes about 20 minutes for the concentration of GH in the bloodstream to decrease by half.

The anterior pituitary gland, located at the base of the brain, is responsible for producing and releasing GH. It is part of the endocrine system, which regulates various bodily functions through hormones.

GH plays a crucial role in growth during childhood and adolescence. It influences bone growth, muscle development, and overall body size.

Growth hormone (GH) stimulates liver cells to produce somatomedins, which are hormones that mediate GH's growth-promoting effects. They are also known as insulin-like growth factors (IGFs).

GH influences bone growth by promoting the formation and differentiation of bone cells (chondrocytes and osteogenic cells), leading to increased bone length and thickness.

GH stimulates protein synthesis and cell division in chondrocytes and osteogenic cells, leading to the growth of bones.

After puberty, the epiphyseal plates in bones fuse, preventing further elongation. However, GH continues to promote bone thickening throughout life.

GH directly stimulates liver cells to synthesize and release somatomedins, which are crucial for GH's actions on bone growth and protein metabolism.

Somatomedin C, also known as IGF-I, acts on bones and protein metabolism to promote growth. Its long-lasting action is due to its strong binding to plasma proteins.

Somatomedin C exerts its effects by activating a second messenger called cyclic AMP, which triggers various cellular responses leading to growth.

IGF-II primarily contributes to fetal growth, playing a crucial role in development during pregnancy.

Human growth hormone, also known as somatotropin, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is produced by the pituitary gland in the brain, and has a role in regulating the body's metabolism.

Growth hormone stimulates the growth of all internal organs except the brain.

Maintaining a stable internal environment in the body is essential for health. Growth hormone plays a role in this process.

The immune system defends the body against invaders. Growth hormone helps to strengthen this defense system.

Growth hormone promotes the conversion of the less active thyroid hormone T4 into the more active T3.

Growth hormone directly stimulates the release of insulin-like growth factor 1 (IGF-1), which plays a major role in growth and development.

Growth hormone secretion is regulated by the hypothalamus, a region in the brain, via a complex feedback loop.

The hypersecretion of growth hormone before the closure of the epiphyses can lead to gigantism.

Acromegaly is a condition that occurs in adults when excess growth hormone (GH) is produced after the bones have stopped growing.

Acromegaly is caused by tumors in the anterior pituitary gland, specifically the acidophil cells, which overproduce GH.

The anterior lobe of the pituitary gland releases tropic hormones, which control other glands.

The characteristic features of Acromegaly include a large face with prominent brow ridges, enlarged hands and feet, and a protruding jaw.

Dwarfism is a condition in children where the pituitary gland doesn't produce enough growth hormone, leading to stunted growth.

The posterior lobe of the pituitary gland stores and releases oxytocin and vasopressin, which are produced by the hypothalamus.

Growth hormone (GH) is produced by somatotropes in the pituitary gland. GH secretion is episodic and regulated by hypothalamic factors and feedback inhibition.

The most common cause of Dwarfism is a tumor in the pituitary gland called a chromophobe tumor. This type of tumor compresses and damages the cells that produce GH.

Panhypopituitarism is a condition where all of the hormones of the anterior pituitary gland are deficient, including GH.

Growth hormone stimulates the production of Insulin-like Growth Factor 1 (IGF-I), which plays a crucial role in growth and development.

Pituitary insufficiency is a condition where the pituitary gland doesn't produce enough hormones. This can lead to various symptoms including growth inhibition, hypoglycemia, and atrophy of adrenal cortex and gonads.

The maximum height of a person with Dwarfism caused by pituitary deficiency is usually about 3 feet, but the proportions of their body are roughly normal.

Surgical removal of the pituitary tumor is the primary treatment for Acromegaly.

GH Deficiency is a specific type of pituitary insufficiency where the pituitary gland doesn't produce enough growth hormone.

GH stimulation tests are used to diagnose GH deficiency. They stimulate the pituitary gland to release GH and analyze the response.

The pituitary gland plays a vital role in regulating various functions, including growth, reproduction, and stress response. Its hormones control other glands and directly affect peripheral organs.