Christian
Active Member, June10MOTM
Starting to think my green tea with ginseng in my pre workout drink might not be such a good idea. Thank you to Fadi for bringing the importance of this hormone to the surface. Just about every company sells some super anabolic caffinated super beverage to consume pre or during workouts.
Might not be the best idea..
From what i have read caffine from a single coffee can elevate cortisol levels by 30% for a period of 12 hours..
Might not be the best idea..
From what i have read caffine from a single coffee can elevate cortisol levels by 30% for a period of 12 hours..
Cortisol is a corticosteroid hormone or glucocorticoid produced by the adrenal cortex, that is part of the adrenal gland (in the zona fasciculata and the zona reticularis of the adrenal cortex). It is usually referred to as the "stress hormone" as it is involved in response to stress and anxiety, controlled by CRH. It increases blood pressure and blood sugar, and reduces immune responses.
Effects
See also Therapeutic uses of glucocorticoids In normal release, cortisol (like other glucocorticoid agents) has widespread actions which help restore homeostasis after stress. (These normal endogenous functions are the basis for the physiological consequences of chronic stress - prolonged cortisol secretion.). It has been proposed that its primary function is to inversely mobilize the immune system to fight potassium-depleting diarrhea diseases.[2]
Insulin Cortisol counteracts insulin by increasing gluconeogenesis and promotes breakdown of lipids (lipolysis), and proteins, and mobilization of extrahepatic amino acids and ketone bodies. This leads to increased circulating glucose concentrations (in the blood) by increasing gluconeogenesis. There is an increased glycogen breakdown in the liver.[3] Prolonged cortisol secretion causes hyperglycemia. The reason why in vivo experiments seem to deny this is that cortisone (a cortisol metabolite) greatly inhibits insulin. So the cortisone-cortisol equilibrium may explain why in vivo experiments contradict the cortisol effect.[4] Cortisol does cause serum glucose to rise, but this is probably an indirect effect caused by stimulation of amino acid degradation, especially that derived from collagen in the skin. In rats, loss of collagen from skin, caused by cortisol, is ten times greater than loss from any other tissue.[5] Amino acids Cortisol raises the free amino acids in the serum. It does this by inhibiting collagen formation, decreasing amino acid uptake by muscle, and inhibiting protein synthesis.[6] Cortisol (as opticortinol) probably inversely inhibits IgA precursor cells in the intestines of calves.[7] Cortisol also inhibits IgA in serum, as it does IgM, but not IgE.[8] Gastric secretion Cortisol stimulates gastric acid secretion.[9] Gastric acid secretion would increase loss of potassium into the stomach during diarrhea as well as acid loss. Cortisol's only direct effect on the hydrogen ion excretion of the kidneys is to stimulate excretion of ammonium ion by inactivation of renal glutaminase enzyme.[10] Net chloride secretion in the intestines is inversely decreased by cortisol in vitro (methylprednisolone).[11] Sodium Cortisol inhibits loss of sodium from small intestines of mammals.[12] However, sodium depletion does not affect cortisol,[13] so cortisol is not used to regulate serum sodium. Cortisol's purpose may originally have been centered around moving sodium because cortisol is used to stimulate sodium inward for fresh water fish and outward for salt-water fish.[14] Potassium Sodium load augments the intense potassium excretion by cortisol, and corticosterone is comparable to cortisol in this case.[15] In order for potassium to move out of the cell, cortisol moves in an equal number of sodium ions.[16] It can be seen that this should make pH regulation much easier, unlike the normal potassium deficiency situation in which about 2 sodium ions move in for each 3 potassium ions that move out, which is closer to the deoxycorticosterone effect. Nevertheless, cortisol consistently causes alkalosis of the serum, while in a deficiency pH does not change. Perhaps this may be for the purpose of bringing serum pH to a value most optimum for some of the immune enzymes during infection in those times when cortisol declines. Potassium is also blocked from loss in the kidneys directly somewhat by decline of cortisol (9 alpha fluorohydrocortisone).[17] Water Cortisol also acts as an anti-diuretic hormone. Half the intestinal diuresis is so controlled.[12] Kidney diuresis is also controlled by cortisol in dogs. The decline in water excretion upon decline of cortisol (dexamethasone) in dogs is probably due to inverse stimulation of antidiuretic hormone (ADH or arginine vasopressin), the inverse stimulation of which is not overridden by water loading.[18] Humans also use this mechanism[19] and other different animal mechanisms operate in the same direction. Copper It is probable that increasing copper availability for immune purposes is the reason many copper enzymes are stimulated to an extent which is often 50% of their total potential by cortisol.[20] This includes lysyl oxidase, an enzyme which is used to cross link collagen and elastin.[21] Particularly valuable for immunity is the stimulation of superoxide dismutase by cortisol[22] since this copper enzyme is almost certainly used by the body to permit superoxide to poison bacteria. Cortisol causes an inverse four- or fivefold decrease of metallothionein, a copper storage protein, in mice[23] (however rodents do not synthesize cortisol themselves). This may be to furnish more copper for ceruloplasmin synthesis or release of free copper. Cortisol has an opposite effect on alpha aminoisobuteric acid than on the other amino acids.[24] If alpha aminoisobuteric acid is used to transport copper through the cell wall, this anomaly would possibly be explained. Immune system Cortisol can weaken the activity of the immune system. Cortisol prevents proliferation of T-cells by rendering the interleukin-2 producer T-cells unresponsive to interleukin-1 (IL-1), and unable to produce the T-cell growth factor.[25] Cortisol has a negative feedback effect on interleukin-1[26] which must be especially useful in combating diseases, such as the endotoxin bacteria, that gain an advantage by forcing the hypothalamus to secrete a hormone called CRH. The suppressor cells are not affected by GRMF,[27] so that the effective set point for the immune cells may be even higher than the set point for physiological processes. It reflects leukocyte redistribution to lymph nodes, bone marrow, and skin. Acute administration of corticosterone (the endogenous Type I and Type II receptor agonist), or RU28362 (a specific Type II receptor agonist), to adrenalectomized animals induced changes in leukocyte distribution. Natural killer cells are not affected by cortisol.[28] Bone metabolism It lowers bone formation thus favoring development of osteoporosis in the long term. Cortisol moves potassium out of cells in exchange for an equal number of sodium ions as mentioned above.[29] This can cause a major problem with the hyperkalemia of metabolic shock from surgery. Cortisol reduces calcium absorption in the intestine.[30] Memory It cooperates with epinephrine (adrenaline) to create memories of short-term emotional events; this is the proposed mechanism for storage of flash bulb memories, and may originate as a means to remember what to avoid in the future. However, long-term exposure to cortisol results in damage to cells in the hippocampus.[31] This damage results in impaired learning. The desirability of inhibiting activity during infection is no doubt the reason why cortisol is responsible for creating euphoria.[32] The desirability of not disturbing tissues weakened by infection or of not cutting off their blood supply could explain the inhibition of pain widely observed for cortisol. Additional effects
- It increases blood pressure by increasing the sensitivity of the vasculature to epinephrine and norepinephrine. In the absence of cortisol, widespread vasodilation occurs.
- It inhibits the secretion of corticotropin-releasing hormone (CRH), resulting in feedback inhibition of ACTH (Adrenocorticotropic hormone or corticotropin) secretion. Some researchers believe that this normal feedback system may become dysregulated when animals are exposed to chronic stress.
- It allows for the kidneys to produce hypotonic urine.
- It has anti-inflammatory effects by reducing histamine secretion and stabilizing lysosomal membranes. The stabilization of lysosomal membranes prevents their rupture, thereby preventing damage to healthy tissues.
- It stimulates hepatic detoxification by inducing tryptophan oxygenase (to reduce serotonin levels in the brain), glutamine synthase (reduce glutamate and ammonia levels in the brain), cytochrome P-450 hemoprotein (mobilizes arachidonic acid), and metallothionein (reduces heavy metals in the body).
- In addition to the effects caused by cortisol binding to the glucocorticoid receptor, because of its molecular similarity to aldosterone, it also binds to the mineralocorticoid receptor. Aldosterone and cortisol have similar affinity for the mineralocorticoid receptor however, glucocorticoids circulate at roughly 100 times the level of mineralocorticoids. An enzyme exists in mineralocorticoid target tissues to prevent overstimulation by glucocorticoids and allow selective mineralocorticoid action. This enzyme, 11-beta hydroxysteroid dehydrogenase type II (Protein:HSD11B2), catalyzes the deactivation of glucocorticoids to 11-dehydro metabolites.