What is one of the primary functions of growth hormone (GH)?

Growth hormone (GH) primarily functions to influence growth and metabolism across various body tissues. One of its significant roles is to promote the use of fats for energy and to facilitate the growth of lean tissue. It acts by helping to maintain adequate levels of glucose in the bloodstream during times of fasting or when energy is needed, and this is where the concept of preventing glucose uptake becomes important.

GH does not stimulate glucose uptake in muscle tissues; rather, it has the effect of conserving glucose by inhibiting its uptake in tissues that are not actively growing. This ensures that glucose is available for essential functions, particularly in the brain. In non-growing tissues, the action of GH helps to redirect energy metabolism away from glucose utilization, favoring the use of free fatty acids instead.

Furthermore, GH is not primarily responsible for enhancing insulin secretion or decreasing fatty acid breakdown; instead, it has the converse effect by promoting lipolysis (fat breakdown) in adipose tissue. Understanding the primary functions of GH helps clarify its role in growth and metabolism, illustrating how it maintains energy balance and nutrient availability in a growing organism.