Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0392674 (exhaustion)
 13,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Both the gonads and the adrenal cortex secret steroids with anabolic activity. It should be realized that the most intense anabolism occurs during infancy and childhood at which time the concentration of steroid hormones with anabolic activity is extremely low. By far the most important anabolic steroid is in testosterone followed by androstenedione, androsterone and dehydroepiandrosterone. Also, estrogens have a generalized anabolic effect, although these hormones have their greatest anabolic action in their respective target organs. In males, after a short period of relatively high T levels immediately after birth, T levels during infancy and childhood are low (+/- 20--30 ng/100 ml); the increase of T levels in one of the first objective signs of puberty and over a period of 3--4 years adult T levels are reached. The latter vary between 380 and 1,000 ng (mean 660 ng/100 ml); the increase in the protein-free, non-protein bound testosterone is even more impressive as the concentration of testosterone binding globulin decreases sharply at puberty. Testosterone levels remain constant up to the 7th decade of life, and decrease rapidly thereafter; free testosterone levels decrease already after the age of 40. T secretion rates in adult males vary between 4 and 10 mg/24 hrs (-/m: 6.6 mg/24 hrs); in males over 65 years the mean T secretion is 4.2 mg/24 hrs: this decrease is a consequence of a decrease in plasma levels and a slowing down of the metabolism. T in adult males originates practically exclusively from the testes. Decreased T levels and secretion rates are observed in hypogonadism and under stressful conditions (anaesthesia, anxiety, hangover, exhaustion, undernutrition) as well as ACTH stimulation. DHT levels parallel generally T levels. Androstenedions (A) in adult males originates in about equal parts from the testes and adrenals. Androstenedione production rates in adult males vary between 1.4--2.1 mg/24 hrs. Dehydroepiandrosterone (DHEA) levels are low in infants and young children. They increase in the immediate pre-pubertal period to reach adult levels after completion of puberty. ACTH as well as stressful situations increase DHEA levels. The mean DHEA production rate is +/- 70 mg/24 hrs. Androsterone is a metabolite of T, A, DHEA, and 170HP, and circulates in plasma essentially as the 3-sulphate and to a lesser extent as the 3-glucuronide. In females, androgen levels before puberty are grossly similar to levels in male children. Pre- and post-menopausal levels of T, DHT, DHEA and their rates of production are discussed. Estrogens have also some anabolic effects. Levels of estradiol (E2) and estrone (E1) in cycling and post-menopausal women are also given. In post-menopausal women E2 levels are extremely low. E2 production rates in post-menopausal women are of the order of 5--20 mug/24 hrs. Progesterone does not appear to have an anabolic effect...
 ...
PMID:Plasma levels and secretion rate of steroids with anabolic activity in man. 13 98

The relationship between muscular work and adrenal function was investigated by using daily swimming exercise in the rat. 1. Adrenal in vitro sensitivity to ACTH was found to have increased after six weeks of swimming training 2. In the development of adaptation the main part was played by muscular exercise itself, since a conditioning of the animals merely to the circumstances of swimming failed to stimulate such adaptive changes as seen in the course of regular physical training. 3. Plasma steroid response to certain stressor agents, such as histamine or acute exhaustion (decrease), respectively to ACTH administration (increase) was similar in ACTH-pretreated and regularly exercised animals. 4. In the 6th to 12th weeks of exercise the trained animals developed a lower plasma steroid content at rest than the controls. This feature was retained even four weeks after the cessation of training sessions. Experimental physical training reduced post-exercise steroidemia in the period of adaptation, that is, after the 6th week. After a pause of 4 weeks, however, the post-exercise steroidemia approached again the control values.
 ...
PMID:Further experimental results concerning the relationship of muscular exercise and adrenal function. 17 4

Attempts have been made to establish whether the immunoreactive corticotrophin (IR-ACTH) reserve was impaired in old age during surgical stress and whether an exhaustion of the IR-ACTH reserve could be traced postoperatively. Recognition of the degenerative changes of the senescent adenohypophysis has made this investigation essential in an effort to analyze factors responsible for the high risk involved in surgery on the aged. In the study 18 young and 14 elderly patients were subjected to elective abdominal or thoracic surgery, and the IR-ACTH response was determined. No significant age-related difference in response to surgery was found. On the 5th day after operation an intravenous metyrapone test was carried out, and the IR-ACTH response in plasma determined. In the elderly, the IR-ACTH response to metyrapone was not found to be inferior to that in the young patients. It was concluded that the IR-ACTH reserve was unimpaired during surgery in old age and that exhaustion was not in evidence based on unimpaired IR-ACTH response during repeated stress in the postoperative period. Therefore, decreased ACTH reserve seems not to be a factor involved in the higher surgical risk in the elderly.
 ...
PMID:Immunoreactive corticotrophin reserve in old age in man during and after surgical stress. 18 20

In patients with thyrotoxicosis combined with primary affection of the central nervous system (CNS)-encephalitis, diencephalitis-there was revealed, like in common thyrotoxicosis, an increased production by the adrenal cortex of hydrocortisone, its intensified transformation and inactivation, reduced production of 17-ketosteroid chiefly due to the fall of dehydroepiandrosterone content, an increased urinary excretion of adrenaline and a decreased-of noradrenaline. The use of functional test with the ACTH administration demonstrated organic affection of the CNS to sharply aggravate the weakening and even the exhaustion of the functional reserves of the glomerular and the reticular zones of the adrenal cortex developing during thyrotoxicosis, and also the reserve possibilities of the sympathico-adrenal system. Direction of the changes in the 24-hour excretion of 17-OCS and corticosteriods was the same in the majority of cases. The latter can point to the presence of functional association between the hypothalamus-hypophysis-adrenal cortex systems and adrenergic regulation in these patients.
 ...
PMID:[Glucocorticoid and androgenic functions of the adrenal cortex and the state of the sympathetic-adrenal system in thyrotoxicosis with primary organic disease of the central nervous system]. 56 23

From the literature we can make the following statements concerning the role of glucocorticoids in exercise and training. These conclusions are summarized graphically in Figure 3. 1. The principle physiological functions of glucocorticoids are stimulation of gluconeogenesis and mobilization of amino acids and fatty acids from body stores. 2. Injected glucocorticoids produce significant increases in the work produced by isolated muscle and by intact animals. 3. Light to moderate exercise work loads may produce an increase, decrease or no change in plasma glucocorticoid (GC) levels; depending on the degree of psychological and/or physiological stress involved in the exercise. 4. In moderate to exhaustive exercise the plasma GC levels progressively increase. In some subjects (especially animals) exhaustion produces a decrease in plasma GC which may represent a defense mechanism to prevent depletion of body resources. 5. Chronic exercise training produces adrenal cortex hypertrophy and usually a smaller rise in plasma GC during an acute exercise bout than that obtained with nontrained subjects. The resting GC levels frequently increase initially during training but return to normal as the trained state is reached. 6. The changes in GC response during training appear to be produced by decreased responsiveness of the adrenal cortex itself to ACTH stimulation and possibly by adaptation of the hypothalamus-hypophysis axis which reduces the ACTH released in response to stress. 7. The many combinations of psychological and physiological stress present in different exercise regimens probably account for the variety of GC responses to exercise reported in the literature.
 ...
PMID:The role of glucocorticoids in exercise. 114 55

The effects of cortisol on the excitability of the dorsal hippocampus, septum, hypothalamus and the pontine reticular formation in unrestrained, unanesthetized rats with permanently-implanted electrodes were investigated. The hormone produced a slowing in the spontaneous activity in these regions. The stimulation of the septum, hypothalamus and reticular formation had no appreciable influence on the local or propagated electrical activity of the brain after cortisol injection; however in 14 out of 29 experiments hippocampal stimulation with the same voltages as before cortisol administration, induced generalized convulsive activity. The attacks consisted of high-voltage spikes and slow-wave activity and were followed by a post-seizure exhaustion in the hippocampus. In half of the rats behavioral convulsions also appeared. The convulsive effects of cortisol on the brain are briefly reviewed and the specificity of hippocampal involvement in the present experiments is emphasized. The possible significance of the present findings in relation to the feedback of glucocorticoids on the brain, in the regulation of ACTH secretion, is discussed. The experiments described may also contribute to our understanding of the mechanisms of the convulsive effects of cortisol on the brain.
 ...
PMID:Effect of cortisol on the excitability of limbic structures of the brain in freely moving rats. 115 57

A 74-year-old housewife was admitted to the hospital with complaints of high fever and general fatigue. The physical examinations on admission showed no particular findings except for mild hepatomegaly, but laboratory findings showed severe liver dysfunction, active inflammation and negative tuberculine test. On the 4th day, she suddenly complained of severe respiratory distress. A chest X-ray film demonstrated surprising changes in comparison with that taken on admission. On suspicion of adult respiratory distress syndrome (ARDS) associated with military tuberculosis (Miliary TB), administration of Methylpredonisolone (1000 mg a day for 3 days) in addition to antituberculous drugs was immediately started. With this therapy she was recovered from such ill condition, but the general exhaustion and slight fever continued. We suspected that her condition might be due to adrenocortical involvement of Miliary TB and hormonal examinations were performed. Unexpectedly, Cushing's syndrome was suspected on the basis of the following; high level of plasma cortisol without normal daily variation, normal ACTH level, an absent response to the Dexamethasone suppression test. Computed tomography revealed left side adrenal mass. During these examinations, renal dysfunction probably due to Miliary TB grew gradually worse and she died of renal failure on the 56th day. Necropsy revealed disseminated tuberculosis involving the lungs and the liver, but the adrenal glands were not examined.
 ...
PMID:[A case of miliary tuberculosis (miliary TB) accompanied with adult respiratory distress syndrome (ARDS) in a patient with Cushing's syndrome]. 140 68

Rats exposed to stress by fixation develop a complex of hormonal metabolic homeostasis disturbances (as evidenced by changed levels of ACTH, insulin, 11-HOCS, urea, glucose). One of the major mechanisms of these disorders in reduced hypothalamus sensitivity to regulatory signals and exhausted adrenocortical functional activity, developing at the stages of anxiety and exhaustion of the adaptation syndrome, respectively, and detectable by functional tests with dexamethasone and ACTH. Administration of natural adaptogens (Scutellaria baicalensis extract and its active principle, baikalin flavonoid) was conducive to normalization of the majority of the examined parameters whatever the direction of changes.
 ...
PMID:[Correction by natural adaptogens of hormonal-metabolic status disorders in rats during the development of adaptation syndrome using functional tests with dexamethasone and ACTH]. 166 2

The effects of ingesting a low dose of CHO on plasma glucose, glucoregulatory hormone responses, and performance during prolonged cycling were investigated. Nine male subjects cycled for 165 min at approximately 67% peak VO2 followed by a two-stage performance ride to exhaustion on two occasions in the laboratory. Every 20 min during exercise, subjects consumed either a flavored water placebo (P) or a dilute carbohydrate beverage (C). Blood samples were collected immediately before, every 20 min throughout, and immediately after exercise. Plasma was analyzed for glucose, lactate, free fatty acids (FFA), and various glucoregulatory hormones. VO2, RER, heart rate, perceived exertion, and exercise performance were also measured. Lactate, FFA, epinephrine, norepinephrine, ACTH, cortisol, and glucagon increased with exercise whereas glucose and insulin decreased (p < or = .05). Except for a small difference in glucose at 158 min of exercise and at exhaustion, no significant differences were found between drinks for any of the variables studied (P > or = .05). Ingestion of 13 g carbohydrate per hour is not sufficient to maintain plasma glucose, attenuate the glucoregulatory hormone response, and improve performance during prolonged moderate intensity cycling.
 ...
PMID:Failure of low dose carbohydrate feeding to attenuate glucoregulatory hormone responses and improve endurance performance. 166 7

The purpose of this study was to determine the intensity threshold needed to elicit increases in plasma aldosterone and cortisol during graded exercise in humans. Seven male volunteers performed a maximal oxygen uptake (VO2max) test on a cycle ergometer. Plasma levels of aldosterone, cortisol, angiotensin II, ACTH, and potassium were measured at rest and at each 50 W workload of the exercise test. The results showed that aldosterone significantly (p less than or equal to 0.05) increased from a mean (+/- SE) of 231 +/- 22 pmol/L at rest to 464 +/- 22 pmol/L at exhaustion. Cortisol significantly (p less than or equal to 0.05) increased from 284 +/- 38 nmol/L at rest to 311 +/- 39 nmol/L at exhaustion. More importantly, however, was the fact that aldosterone was significantly increased above the resting level at exercise intensities greater than or equal to 60% VO2max. Cortisol, on the other hand, was only significantly increased at exhaustion (i.e. 100% VO2max). These results clearly show that increases in aldosterone precede those of cortisol during graded exercise in humans. Interestingly, potassium (r = 0.79), ACTH (r = 0.55), and angiotensin II (r = 0.54) were all significantly correlated with aldosterone during exercise. Such a finding seems to suggest that all 3 variables may be important stimuli for aldosterone secretion during graded exercise.
 ...
PMID:Increases in aldosterone precede those of cortisol during graded exercise. 186 83


1 2 3 4 5 Next >>