Biological potency is determined by measuring the increase in body weight induced in hypophysectomized rats. The reconstituted solution has a pH of 6.5 to 8.5. The pH is adjusted with sodium hydroxide or O-phosphoric acid. Clinical studies in normal adults also demonstrated equivalent pharmacokinetics. Skeletal growth is accomplished at the epiphyseal plates at the ends of long bone.
Linear growth continues until the growth plates fuse at the end of puberty.
This is reflected by increased cellular uptake of amino acids and nitrogen retention as demonstrated by a decline in urinary nitrogen excretion and blood urea nitrogen during growth hormone therapy. Carbohydrate Metabolism-Growth hormone is a modulator of carbohydrate metabolism. Children with inadequate secretion of growth hormone sometimes experience fasting hypoglycemia that is improved by treatment with growth hormone. However, glucose levels remained in the normal range. Lipid Metabolism-Acute administration of human growth hormone to humans results in lipid mobilization.