Caffeine hormonal

Diarrhea is a common problem that is usually self-limiting and of short duration. Increased accumulations of small intestinal and colonic contents are known to be responsible for producing diarrhea. The former may be caused by increased intestinal secretion which may be enterotoxin-induced, eg, cholera and E. col] or hormone and dmg-induced, eg, caffeine, prostaglandins, and laxatives decreased intestinal absorption because of decreased mucosal surface area, mucosal disease, eg, tropical spme, or osmotic deficiency, eg, disaccharidase or lactase deficiency and rapid transit of contents. An increased accumulation of colonic content may be linked to increased colonic secretion owing to hydroxy fatty acid or bile acids, and exudation, eg, inflammatory bowel disease or amebiasis decreased colonic absorption caused by decreased surface area, mucosal disease, and osmotic factors and rapid transit, eg, irritable bowel syndrome. 

The different types or classes of phytochemicals can have multiple influences on the GIT (Kitts, 1994). For example, caffeine stimulates the motor, hormonal and secretory functions (Boekmaefa/., 1999). Although many phytochemicals reduce nutrient quality or availability, traditional herbal medicines have exploited some of these characteristics to improve health. Moreover, some of the systemic responses attributed to certain phytochemicals (beneficial or detrimental) can be explained by their influences on the GIT (Carbonaro et al., 2001). To date, the most of the information about phytochemicals is focused on the reductions in the functional capacities of the GIT (the bad), or the toxic properties (the ugly). There are also numerous examples of phytochemicals that can be used to obtain desirable GIT characteristics (the... 

Caffeine and theophylline stimulate pancreatic hormone secretions even in normal doses. 

Finally, there is virtually no mention of the fact that the majority of test subjects in the caffeine research literature are reported to be males, so that hormonal differences in respect to caffeine s ergogenic effects may be a topic that requires further examination. 

Caffeine intake inversely associated with bone density, independent of dietary anthropometric and hormonal factors. 

High doses of caffeine produce a stresslike neuroendocrine response (Spindel 1984 Spindel et al. 1984). This includes increased levels of corticosterone, jS-endorphin, and decreased serum growth hormone and thyrotropin-stimulating hormone in the rat. However, similar effects are not observed in humans until approximately 500 mg is consumed, the equivalent of 5 cups of coffee. At this dose in humans, elevations are seen in adrenocorticotrophic hormone, jS-endorphin, and cortisol. 

Metabolic clearance of caffeine is altered according to menstrual phase and hormonal status in women (Lane et al. 1992). Clearance is slower during the late luteal phase compared to the follicular phase, prior to the onset of menstruation. However, the size of the effect and significance in everyday activity remains in question. 

Stress and stress hormones Anxiety or stress can increase energy expenditure, although the effect is small. It is caused by increased sympathetic activity and hence increased levels of the stress hormones adrenaline and noradrenaline. Injection of these hormones increases oxygen consumption, as does caffeine, which... 

Uhde TW, Tancer ME, Rubinow DR (1992) Evidence for hypothalamo-growth hormone dysfunction in panic disorder profile of growth hormone responses to clonidine, yohimbine, caffeine, glucose, GRF, and TRH in panic disorder patients vs. healthy volunteers. N europsychopharmacology 6 101-118... 

Although the effect of caffeine cannot be distinguished from the effects of coffee and green tea, consumption of caffeine-containing beverages favorably altered hormone levels associated with the risk of developing breast cancer . 

Johnston, K.L., Clifford, M.N., and Morgan, L.M., Coffee acutely modifies gastrointestinal hormone secretion and glucose tolerance in humans glycemic effects of chlorogenic acid and caffeine. Am. J. Clin. Nutr., 78, 728, 2003. 

When the hormonal stimulus stops, the intracellular actions of cAMP are terminated by an elaborate series of enzymes. cAMP-stimulated phosphorylation of enzyme substrates is rapidly reversed by a diverse group of specific and nonspecific phosphatases. cAMP itself is degraded to 5 -AMP by several cyclic nucleotide phosphodiesterases (PDE Figure 2-13). Competitive inhibition of cAMP degradation is one way caffeine, theophylline, and other methylxanthines produce their effects (see Chapter 20). 

Levodopa or dopamine agonists produce diverse dyskinesias as a dose-related phenomenon in patients with Parkinson s disease dose reduction reverses them. Chorea may also develop in patients receiving phenytoin, carbamazepine, amphetamines, lithium, and oral contraceptives, and it resolves with discontinuance of the offending medication. Dystonia has resulted from administration of dopaminergic agents, lithium, serotonin reuptake inhibitors, carbamazepine, and metoclopramide and postural tremor from theophylline, caffeine, lithium, valproic acid, thyroid hormone, tricyclic antidepressants, and isoproterenol. 

Certain foreign compounds may cause the retention or excretion of water. Some compounds, such as the drug furosemide, are used therapeutically as diuretics. Other compounds causing diuresis are ethanol, caffeine, and certain mercury compounds such as mersalyl. Diuresis can be the result of a direct effect on the kidney, as with mercury compounds, which inhibit the reabsorption of chloride, whereas other diuretics such as ethanol influence the production of antidiuretic hormone by the pituitary. Changes in electrolyte balance may occur as a result of excessive excretion of an anion or cation. For example, salicylate-induced alkalosis leads to excretion of Na+, and ethylene glycol causes the depletion of calcium, excreted as calcium oxalate. 

The intracellular signal therefore persists only as long as the hormone receptor remains occupied by epinephrine. Methyl xanthines such as caffeine and theophylline (a component of tea) inhibit the phosphodiesterase, increasing the half-life of cAMP and thereby potentiating agents that act by stimulating adenylyl cyclase. 

Hydrolysis of cAMP cAMP is rapidly hydrolyzed to 5-AMP by cAMP phosphodiesterase, one of a family of enzymes that cleave the cyclic 3 5 -phosphodiester bond. 5-AMP is not an intracellular signalling molecule. Thus, the effects of neurotransmitter- or hormone-mediated increases of cAMP are rapidly terminated if the extracellular signal is removed. [Note Phosphodiesterase is inhibited by methylxanthine derivatives, such as theophylline and caffeine.3]... 

CNS, smooth muscle T diuresis X- pit aggregation Available forms Daily t doses w/ max 3 g PO daily Contra Avoid in PRG lactation, CAD, hyperthyroidism, anxiety disorders d/t high, caffeine content Notes/SE Insomnia, tach, anxiety, N/V, HA, HTN, Sz Interactions T Effects OF anticoagulants, anti-pits, BBs, bron-choclilators T risk of hypertensive crisis W/ MAOIs T effects W/ cimetidine, ciprofloxacin, ephedrine, hormonal contraceptives, dieophylline, cola, coffee X-effects OF adenosine, antihypertensives, benzodiazepines, Fe, X- effects W/ smoking EMS Tinctures contain EtOH may exacerbate GI disorders HTN T effects of anticoagulants and BBs... 

Theophylline is found in coffee and in tea in very small amounts, but it has a stronger effect on the heart and breathing than does CF. Along with CF, TP is used as a medicine to treat emphysema and bronchitis (254,255). Caffeine and TP inhibit cAMP phosphodiesterase. In their presence the effects of cAMP, and thus the stimulatory effects of the hormones that lead to its production, are prolonged and intensified. 

Norephedrine and ephedrine mimic and stimulate the release of the adrenal hormones norepinephrine and epinephrine. Norephinephrine raises heart rate and epinephrine stimulates carbohydrate metabolism resulting in an increased metabolic rate, fatty acids release from lipocytes (fat cells), and a protein sparing effect. Caffeine simply prolongs the effect. 

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