Which hormone is responsible for increasing amino acid uptake and protein synthesis?

The hormone responsible for increasing amino acid uptake and promoting protein synthesis is growth hormone. Growth hormone, produced by the pituitary gland, plays a crucial role in growth, cell repair, and metabolism. It stimulates the liver and other tissues to enhance the uptake of amino acids, which are the building blocks of proteins. This results in increased protein synthesis, which is essential for muscle growth and repair, as well as overall tissue development.

Additionally, growth hormone promotes lipolysis, the breakdown of fats, and influences muscle mass. Its anabolic effects on muscle and tissues make it vital for recovery from injury, physical performance, and growth during adolescence.

In contrast, while cortisol is a steroid hormone that can affect protein metabolism, it primarily acts to increase blood glucose levels and can have catabolic effects on proteins when levels are excessively high. Insulin plays a significant role in facilitating glucose uptake and can help with amino acid uptake, but its primary function is more related to carbohydrate metabolism. Thyroid hormone affects metabolism on a broader scale by regulating energy use and basal metabolic rate but does not directly increase amino acid uptake like growth hormone does. Thus, growth hormone is the key hormone for enhancing protein synthesis and amino acid uptake.