Adrenal Physiology II Flashcards
One of the primary metabolic actions of cortisol is to elevate
Blood [glucose]
Cortisol increases glucoe levels by stimulating
Gluconeogenesis and glycogen storage
Promotes the production of epinephrine, has a permissive effect on glucagon, and mediates the activation of glycogen phosphorylase, all of which facilitate glycogenolysis
Cortisol
Exerts an overall anabolic effect in the liver by activating the expression of enzymes involved in gluconeogenesis and glycogen storage
Cortisol
In muscle, has a catabolic effect by by inhibiting protein synthesis and promoting protein breakdown
Cortisol
Induces acute lipolysis in adipose tissue and stimulated the action of other lypolytic stimuli
Cortisol
Cortisols actue action on adipose releases which 2 things?
- ) Glycerol for gluconeogenesis
2. ) FFA for ATP
At the same time, cortisol can markedly stimulate appetite and promote
Lipogenesis in specific tissues
Cortisol actually promotes lipogenesis in specific tissues, most notably the
Abdomen, trunk, neck, and face
Thus a prolonged excess of cortisol in the body results in
Obesity
Cortisol opposes the key action of
Insulin
Cortisol inhibits insulin stimulated glucose uptake in muscle and adipose tissue and reverses insulin suppression of
Hepatic Glucose production
Inhibits bone formation by decreasing both intestinal absorption of calcium and renal calcium reabsorption
Cortisol
As a result of this lowered serum Ca2+, we see increased bone reabsorption via the release of
PTH
Cortisol also inhibits bone formation by directly acting on osteoblasts and osteocytes to suppress
Collagen synthesis
Cortisol also increases the rate of apoptosis of
Osteoblasts and osteocytes
Cortisol also indirectly increases bone resorption by regulating the production of growth factors and cytokines that stimulate
Osteoclast formation
In the skin, cortisol inhibits the proliferation of connective tissue (i.e. fibroblasts) and the synthesis of
Collagen
Excess cortisol results in the thinning of skin and of the walls of capillaries; the fragility of the capillaries leads to frequent
Rupture and bruising
In excess, cortisol can act as a mineralocorticoid receptor agonist and stimulate
Na+ reabsorption and K+ secretion
Promiscuous cortisol action in the kidney is normally held in check by the
Type 2 11-HSD
Cortisol and other synthetic glucocorticoids are the most powerful
Anti-inflammatory agents
An inflammatory response to an injury typically consists of local dilation of capillaries and increased capillary permeability enhancing the trapping of
Leukocytes
These steps are mediated by thromboxanes, leukotrienes and prostaglandins which are all derived from
Phosphatidyl choline