Growth hormone glucagon

Hormones can modify the concentration of precursors, particularly the lipolytic hormones (growth hormone, glucagon, adrenaline) and cortisol. The lipolytic hormones stimulate lipolysis in adipose tissue so that they increase glycerol release and the glycerol is then available for gluconeogenesis. Cortisol increases protein degradation in muscle, which increases the release of amino acids (especially glutamine and alanine) from muscle (Chapter 18). 

Adrenaline Noradrenaline (+) Growth hormone Glucagon Insulin ... 

Otfier fiormones accelerate tfie release of free fatty acids from adipose tissue and raise tfie plasma free fatty acid concentration by increasing the rate of lipolysis of the triacylglycerol stores (Figure 25—8). These include epinephrine, norepinephrine, glucagon, adrenocorticotropic hormone (ACTH), a- and P-melanocyte-stimulat-ing hormones (MSH), thyroid-stimulating hormone (TSH), growth hormone (GH), and vasopressin. Many of these activate the hormone-sensitive hpase. For an optimal effect, most of these lipolytic processes require the presence of glucocorticoids and thyroid hormones. These hormones act in a facilitatory or permissive capacity with respect to other lipolytic endocrine factors. 

The scope of applicability of radioimmunoassay is rapidly expanding with the dawn of each day as RIA is being developed for newer pharmaceutical substances. It has attained wide recognition and application both in vitro and in vivo measurements of compounds of interest like insulin, gastrin, glucagon, and growth hormones on one hand whereas drugs like ... 

Insulin, growth hormone, and glucagon are key protein hormones... 

An excess of insulin can cause hypoglycaemia and the hormones that respond to this condition to restore normal glucose levels are known as the counter-regulatory hormones. They are adrenaline, glucagon, growth hormone and cortisol. An increase in the blood levels of these hormones can sometimes be used to conhrm a diagnosis of hypoglycaemia. 

Changes in hormone levels in starvation can extend the control provided by the cycle. The levels of glucagon and growth hormone are increased, which stimulates lipolysis, and the level of insnUn is decreased, which decreases rates of glncose nptake bnt increases lipolysis and hence fatty acid mobilisation (Fignres 16.3 and 16.4). 

Figure 16.4 Effect of several hormones on the glucose/fatty acid cycle. Catecholamines, glucagon and growth hormone stimulate lipolysis in adipose tissue and hence antagonise the effects of insulin.

A further objective was to develop compounds with selectivity for inhibition of release of glucagon and/or growth hormone. 

The potencies of 4-6 for inhibition of release of insulin and glucagon vivo follow trends similar to the growth hormone data although the absolute magnitudes are somewhat different. 

True endocrine hormones, however, remain a fairly well-defined group. Virtually all of the hormones used therapeutically (discussed below) fit into this grouping. Examples include insulin, glucagon, growth hormone and the gonadotrophins. 

Octreotide acetate (Sandostatin) is a synthetic peptide analogue of the hormone somatostatin. Its actions include inhibition of the pituitary secretion of growth hormone and an inhibition of pancreatic islet cell secretion of insulin and glucagon. Unlike somatostatin, which has a plasma half-life of a few minutes, octreotide has a plasma elimination half-Hfe of 1 to 2 hours. Excretion of the drug is primarily renal. 

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