The effects of alcohol on the endocrine system

Administration of increasing doses of gonadotropin-releasing hormone in men with spinal cord injury to investigate dysfunction of the hypothalamic-pituitary-gonadal axis

STUDY DESIGN

Prospective.

OBJECTIVES

To determine the optimum gonadotropin-releasing hormone (GnRH) dose to identify dysfunction of the hypothalamic-pituitary-gonadal axis in men with spinal cord injury (SCI).

SETTING

Metropolitan Area Hospitals, New York and New Jersey, USA.

METHODS

SCI men (16 hypogonadal (HG = serum testosterone <12.1 nmol/l) and 14 eugonadal (EG)) and able-bodied (AB) men (27 HG and 11 EG) were studied. GnRH (10, 50, and 100 μg) was randomly administered intravenously on three separate visits. Blood samples were collected post-GnRH for serum-luteinizing hormone (LH) and follicular-stimulating hormone (FSH).

RESULTS

HG and EG men had a similar proportion of clinically acceptable gonadotropin responses to all three GnRH doses. The incremental gonadotropin responses to GnRH were not significantly different across the groups. However, in the SCI-HG group, GnRH of 100 μg resulted in the greatest integrated FSH response, and in the SCI-EG group, GnRH of 50 μg resulted in the greatest integrated LH response compared with the AB groups. A consistent, but not significant, absolute increase in gonadotropin release was observed in the SCI groups at all GnRH doses.

CONCLUSIONS

Lower doses of GnRH did not improve the ability to identify the clinical dysfunction of the hypothalamic-pituitary-gonadal axis. However, the absolutely higher SCI-HG FSH response to GnRH of 100 μg and a higher SCI-EG LH response to GnRH of 50 μg, along with a higher gonadotropin release at all GnRH doses, albeit not significant, suggests a hypothalamic-pituitary dysfunction in persons with SCI.

Impact of alcohol use on thyroid function

Alcohol is one of the commonest illicit psychoactive substances consumed globally and is the world's third largest risk factor for disease and disability. It has been reported to have multiple effects on the hypothalamo-pituitary-thyroid axis and the functioning of the thyroid gland. It has been reported to cause direct suppression of thyroid function by cellular toxicity, and indirect suppression by blunting thyrotropin-releasing hormone response. It causes a decrease of peripheral thyroid hormones during chronic use and in withdrawal. Alcohol use may also confer some protective effect against thyroid nodularity, goiter, and thyroid cancer. This article presents a review of the clinically relevant effects of alcohol on the functioning of the thyroid gland and also discusses the effect of medication used in treatment of alcohol dependence on thyroid function.

Drug-induced gynecomastia

Drugs account for about 20% of gynecomastia cases in men. As a number of factors can alter the estrogen:androgen ratio, several pathophysiologic mechanisms are associated with drugs causing this disorder. Antiandrogens, protease inhibitors, and nucleoside reverse transcriptase inhibitors are the most common drug causes of gynecomastia, whereas first-generation antipsychotics, spironolactone, verapamil, and cimetidine are less common causes. Other drugs have been reported rarely as causes. Treatment may involve switching to an alternative agent or may require surgery or irradiation if the causative agent cannot be discontinued. We reviewed the literature on drug-induced gynecomastia and provided another perspective by reviewing data from the United States Food and Drug Administration's Adverse Event Reporting System. Epidemiologic studies are needed to provide a more accurate description of the frequency of drug-induced gynecomastia.

Differential effects of chronic ethanol exposure on cytochrome P450 2E1 and the hypothalamic-pituitary-adrenal axis in the maternal-fetal unit of the guinea pig

BACKGROUND

Ethanol neurobehavioural teratogenicity is a leading cause of developmental mental deficiency, in which the hippocampus is a target site of injury. The multi-faceted mechanism of ethanol teratogenicity is not completely understood. This study tested the hypothesis that chronic ethanol exposure (CEE), via chronic maternal ethanol administration, increases cytochrome P450 2E1 (CYP2E1) expression and alters hypothalamic-pituitary-adrenal (HPA) axis activity in the maternal-fetal unit during the third-trimester-equivalent of gestation.

METHODS

Pregnant Dunkin-Hartley-strain guinea pigs received daily oral administration of ethanol (4 g ethanol/kg maternal body weight) or isocaloric-sucrose/pair-feeding (control) throughout gestation (term, about gestational day (GD) 68). On GD 45, 55 and 65, pregnant animals were euthanized 2h after the last daily dose. Maternal and fetal body weights and fetal hippocampal brain weight were determined. Maternal and fetal samples were collected for the determination of liver CYP2E1 enzymatic activity and plasma free cortisol and ACTH concentrations.

RESULTS

CEE, with maternal blood ethanol concentration of 108-124 mg/dl at 2h after the last dose, decreased fetal hippocampal weight only at GD 65 and had no effect on fetal body weight compared with control. CYP2E1 activity increased with gestational age in the fetal liver microsomal and mitochondrial fractions. CEE increased CYP2E1 activity in the microsomal and mitochondrial fractions of maternal liver at the three gestational ages and in both hepatic subcellular fractions of the GD 65 fetus compared with control. There was a gestational-age-dependent increase in maternal and fetal plasma free cortisol concentrations, but no effect of CEE compared with control. Maternal and fetal plasma ACTH concentrations were unaffected by CEE compared with control, and were virtually unchanged during the third-trimester-equivalent that was studied.

CONCLUSION

These data demonstrate that, in the pregnant guinea pig, this CEE regimen increases liver CYP2E1 activity, without affecting HPA axis function, in the maternal-fetal unit during near-term gestation. The CEE-induced increase in liver CYP2E1 activity and potential oxidative stress in the maternal-fetal unit may play a role in the pathogenesis of ethanol teratogenicity.

An assessment of potential cancer risk following occupational exposure to ethanol

Recognition of the carcinogenic properties of ethanol has resulted from comprehensive evidence regarding the effect of consumption of alcohol; indeed, ethanol in alcoholic beverages is now considered a Group 1 carcinogen by the International Agency for Research on Cancer. However, there is little information on the effects of ethanol following exposure via the occupationally relevant routes of inhalation and dermal exposure. This review therefore focuses on these exposure routes, to assess potential carcinogenic risk associated with occupational exposure to ethanol. Inhalatory exposure at the current occupational exposure limit (OEL) for the United Kingdom (1000 ppm ethanol over an 8-h shift) was estimated to be equivalent to ingestion of 10 g ethanol (approximately 1 glass of alcohol) per day. However, in the occupational setting the dose-rate delivery of this amount of ethanol is low, allowing for its rapid and effective elimination, for the majority of individuals. Similarly, while dermal absorption in an occupational setting could potentially add to overall body ethanol burden, additional carcinogenic risk of such exposure is considered negligible. Thus, on balance, there appears little cause to suppose occupational exposure at or below the current OEL associates with any appreciable increase in risk of cancer. However, available occupational exposure data to confirm this view are currently limited. It is also suggested that adoption of a more flexible classification regime, considering risk in the context of hazard and exposure (such as that adopted by the German MAK commission), would represent an improvement over traditional occupational risk assessment practices.

[Pseudo-Cushing states]

Pseudo-Cushing syndromes are a heterogeneous group of disorders, including alcoholism, anorexia nervosa, visceral obesity, and depression, which share many of the clinical and biochemical features of Cushing's syndrome. The mechanisms responsible for the genesis of pseudo-Cushing's syndrome are poorly understood. It has been suggested that hypercortisolism of pseudo-Cushing syndrome may be the result of increased hypothalamic corticotrophin-releasing hormone (CRH) secretion in the context of a hypothalamic-pituitary-adrenal axis that is otherwise normally constituted. The substantial overlap in clinical and biochemical features among several patients with Cushing syndrome and those with pseudo-Cushing syndromes can make the differential diagnosis difficult. Distinguishing between pseudo-Cushing's syndrome and true Cushing's syndrome is critical for preventing the unnecessary and potentially harmful treatment of such patients. This brief review summarizes the main pathophysiological events of pseudo-Cushing syndromes and provides a useful strategy for differential diagnosis.

Cushing’s syndrome in a clinic population with diabetes

BACKGROUND

A recent report has suggested that occult Cushing's syndrome (CS) may be present in a significant number of patients with type 2 diabetes mellitus. The aim of this study was to determine whether any patients in our clinic population with diabetes had this condition.

METHODS

One hundred and seventy-one consecutive overweight attendees at the diabetic clinic were enrolled in a study to assess the presence of occult CS. The initial screen was with the 1 mg overnight dexamethasone suppression test and follow-up testing, where indicated was with a 24 h collection for urine-free cortisol.

RESULTS

Thirty-one of 171 patients had a positive result from the overnight dexamethasone suppression test. Follow-up testing with 24 h urine-free cortisol reduced the number of patients with positive results to 3. Two of these were shown to have alcoholic pseudo-CS. The third patient has had several high urine-free cortisol results, in the presence of normal scans of pituitary and adrenals. He has no stigmata of CS and is being observed.

CONCLUSION

Based on the results of our study, there would appear to be little value in screening type 2 diabetics for CS, in the absence of clinical suspicion.

Increased salivary cortisol concentrations during chronic alcohol intoxication in a naturalistic clinical sample of men

BACKGROUND

Cortisol, the primary glucocorticoid in humans, is intimately involved in the regulation of such varied and critical biological processes as emotion, cognition, reward, immune functioning, and energy utilization. A persistent increase in cortisol concentration as a result of chronic intoxication could therefore result in alcohol-related disorders such as sleep disruption, cognitive deficits, diabetes, and mood disturbances. Although moderate levels of acute alcohol ingestion are reported to produce an increase in cortisol levels, it is uncertain whether cortisol remains persistently increased during long-term chronic intoxication.

METHODS

Salivary cortisol and breath alcohol concentrations (BAC) were obtained on 73 subjects with primary alcohol dependence on initial presentation for treatment and 22 alcohol-dependent subjects participating in a residential treatment program.

RESULTS

Both intoxicated alcohol-dependent subjects (n = 38) and nonintoxicated subjects in acute alcohol withdrawal (n = 30) demonstrated significantly increased salivary cortisol concentrations compared with abstinent subjects (n = 27; p < 0.001). Nonintoxicated subjects in acute withdrawal demonstrated significantly increased salivary cortisol concentrations compared with highly intoxicated subjects (BAC >100 mg/dl) but were similar to subjects with lower levels of intoxication (BAC, 10-100 mg/dl).

CONCLUSIONS

Chronic alcohol-dependent subjects experience continuously increased concentrations of cortisol during both intoxication and withdrawal. Increased levels of cortisol during chronic intoxication seem to progressively increase with the onset of withdrawal. This suggests a daily cycle of hypercortisolemia during the active drinking phase, with further increases on the cessation of drinking and the emergence of withdrawal symptoms. Persistently increased levels of cortisol may extract a costly allostatic load, resulting in significant central nervous system and peripheral organ morbidity.

Acute ethanol administration induces changes in TRH and proenkephalin expression in hypothalamic and limbic regions of rat brain

Thyrotropin releasing hormone (TRH) present in several brain areas has been proposed as a neuromodulator. Its administration produces opposite effects to those observed with acute ethanol consumption. Opioid peptides, in contrast, have been proposed to mediate some of the effects of alcohol intoxication. We measured TRH content and the levels of its mRNA in hypothalamic and limbic zones 1-24 h after acute ethanol injection. We report here fast and transient changes in the content of TRH and its mRNA in these areas. The levels of proenkephalin mRNA varied differently from those of proTRH mRNA, depending on the time and region studied. Wistar rats were administered one dose of ethanol (intraperitoneal, 3 g/kg body weight) and brains dissected in hypothalamus, hippocampus, amygdala, n. accumbens and frontal cortex, for TRH quantification by radioimmunoassay or for proTRH mRNA measurement by RT-PCR. After 1 h injection, TRH levels were increased in hippocampus and decreased in n. accumbens; after 4 h, it decreased in the hypothalamus, frontal cortex and amygdala, recovering to control values in all regions at 24 h. ProTRH mRNA levels increased at 1 h post-injection in total hypothalamus and hippocampus, while they decreased in the frontal cortex. The effect of ethanol was also studied in primary culture of hypothalamic cells; a fast and transient increase in proTRH mRNA was observed at 1 h of incubation (0.001% final ethanol concentration). Changes in the mRNA levels of proTRH and proenkephalin were quantified by in situ hybridization in rats administered ethanol intragastrically (2.5 g/kg). Opposite alterations were observed for these two mRNAs in hippocampus and frontal cortex, while in n. accumbens and the paraventricular nucleus of the hypothalamus, both mRNA levels were increased but with different kinetics. These results give support for TRH and enkephalin neurons as targets of ethanol and, as possible mediators of some of its observed behavioral effects.

Effects of chronic and acute ethanol exposure on renal (Na + K)-ATPase in the rat

1. We evaluated the effects of chronic ethanol consumption on the kinetic properties of renal (Na + K)-ATPase and compared them with acute inhibition by ethanol in vitro. 2. When adult rats were fed 20% ethanol for 10 weeks, renal (Na + K)-ATPase activity increased but the sensitivity of the enzyme to ethanol inhibition in vitro was not altered. 3. Vmax was increased by ethanol consumption, whereas K0.5 and nH were not changed. The kinetic parameters of Mg(2+)-ATPase were not affected under the same conditions. 4. We concluded that ethanol-induced tolerance or enhancement of renal (Na + K)-ATPase or both can be explained on the basis of an increase in Vmax.

Effect of three different modes of alcohol administration on the activity of the rat hypothalamic-pituitary-adrenal axis

The present study compared the effect of different modes of alcohol administration on the activity of the hypothalamic-pituitary-adrenal (HPA) axis. In a first series of studies, we investigated the influence of the intraperitoneal (ip) and intragastric (ig) effect of acutely administered alcohol. Over a 3-hr period, alcohol induced dose-related increases in adrenocorticotropic hormone (ACTH) and alcohol levels in the circulation. There was a good correlation between blood ACTH and alcohol levels (ip treatment, R = 0.84; ig treatment, R = 0.79). Measurement of steady-state mRNA of the immediate early gene NGFI-B, taken as an index of neuronal activation in the paraventricular nucleus (PVN) of the hypothalamus of rats administered 3 g of alcohol/kg, indicated significant (p < 0.01) increases between 60 and 180 min after both ip and ig alcohol injection, with peak stimulation at 1 and 2 hr, respectively. Although NGFI-B mRNA levels had returned to control level in the parvicellular portion of the PVN of animals administered the drug ip 4 hr earlier, they were still significantly (p < 0.01) elevated 4 hr after ig treatment. A second series of studies used rats fed an alcohol diet containing 6.4% alcohol (w/v), or pair-fed. The rats were tested during the 4th or 6th night of treatment. Despite blood alcohol levels ranging between 0.060 and 0.140% w/v, there was no significant rise in plasma ACTH/corticosterone levels in animals fed the drug, and no detectable NGFI-B mRNA in their PVN. Collectively, these results indicate that both the ip and the ig acute injection of alcohol induced dose-related increases in plasma ACTH levels. PVN neuronal activation was also observed. In contrast, the alcohol diet had no effect on HPA hormone levels or PVN expression of NGFI-B.

Contractile protein synthesis rates in vivo in the rat jejunum: modulating role of adrenalectomy and thyroidectomy on ethanol-induced changes

Acute ethanol toxicity has many deleterious effects on the gastrointestinal tract and, in particular, inhibits small intestinal protein synthesis. The mechanism(s) of the ethanol-induced inhibition of protein synthesis are unknown. This study was designed to investigate the role of adrenal and thyroid hormones on the ethanol-induced inhibition of whole jejunal protein synthesis in adrenalectomised and thyroidectomised male Wistar rats. Acute ethanol dosage significantly reduced protein synthesis in all subcellular protein fractions of the whole jejunum, in sham-thyroidectomized, thyroidectomized, sham-ardrenalectomized and adrenalectomized rats. Synthesis rates relative to RNA and DNA were also highly significantly reduced in all treatment groups in ethanol-dosed rats. However in most protein fractions the inhibition of protein synthesis was greater in thyroidectomized compared to sham-thyroidectomized rats, whereas the reverse was true in adrenalectomized rats. Neither adrenalectomy or thyroidectomy completely abolished ethanol-induced inhibition in protein synthesis, suggesting that ethanol or its metabolites, e.g. acetaldehyde, acts directly on the tissue. However, the ethanol-induced inhibition of protein synthesis was greater in thyroidectomized rats demonstrating that contractile and non-contractile proteins synthesis in the jejunum is under control of complex regulatory processes.

Studies on the site of ethanol action in inducing prolactin release in male rats

Hypersecretion of prolactin (PRL) has been implicated as one of the factors that mediate ethanol-induced hypogonadism, but the site(s) in the central nervous system where ethanol acts to lead to the stimulation of PRL secretion is unknown. To clarify the site(s) of ethanol action, medial basal hypothalamic deafferentation (MBHD) or medial basal hypothalamic ablation (MBHA) were performed stereotaxically in male rats, and their PRL secretory capacity in response to acute ethanol administration was compared with that of intact or sham-operated controls. In intact control rats, plasma immunoreactive PRL concentration increased markedly (P < .001 v saline injection) following ethanol 400 to 500 mg/100 g body weight (BW) intraperitoneally (IP). The PRL response was dose-related and reached a maximum plateau level at 15 minutes. Plasma PRL returned to a near-basal level by 60 minutes. The response was blocked completely (P < .001) by pretreatment with dopamine (1 mg per rat), a specific inhibitor of adenohypophyseal PRL secretion. In sham-operated rats and in MBHD and MBHA rats, ethanol (500 mg/100 g BW IP) induced a significant (P < .001 to .05) elevation of PRL relative to the respective saline treatment. The basal level was significantly (P < .005) lower in the MBHD group (5.3 +/- 0.9 ng/mL) and significantly (P < .001) higher in the MBHA group (101.1 +/- 15.7 ng/mL) than in the sham group (17.2 +/- 5.9 ng/mL). These results suggest the following: (1) acute ethanol administration stimulates PRL secretion from the pituitary in a dose-related manner, (2) ethanol appears to have direct stimulatory effects on adenohypophyseal PRL secretion, and (3) extrahypothalamic brain areas exert a stimulatory influence and the hypothalamus an inhibitory influence on basal PRL secretion.

Effect of chronic ethanol consumption on the activities of residual small bowel brush-border enzymes after proximal jejunum resection in the rat

Ethanol consumption has a toxic effect on the epithelium of the small bowel, but enterocyte maturity is very difficult to measure under these circumstances. However, when ethanol intake is combined with enterectomy, enterocyte immaturity is greater, permitting an easier separation of these two effects. In a group of rats (13 male Wistar rats weighing approximately 220 g) fed a liquid diet containing 35% ethanol for 4 weeks after resection of the proximal jejunum, the residual small intestine brush border maltase, sucrase, and lactase activities were similar to those of a pair-fed control group (13 animals). However, alkaline phosphatase activity was decreased in the mucosa and in the enterocyte brush border, probably because of the lower activity of this enzyme in the jejunum-ileum remnant of the alcoholic group.

Alcohol, corticosteroids, energy utilization, and hippocampal endangerment

The cellular weakening or cytoxic consequences of CAC are intertwined in the most fundamental sense with energy intake, production, storage, and mobilization. The impact of CAC on the HPA axis to increase GCs makes this energy regulatory hormone along with pancreatic hormones a potential major player in the site-specific organ pathologies associated with CAC. Although little is known about the mechanism of CAC neurotoxicity, the hippocampal endangerment model which relies heavily on the cellular weakening, site-specific effect of continuous or chronic, intermittent (withdrawal, binge drinking) elevation of GCs, even less is known about the mechanism of neurotoxicity of activating the ethanol-inducible CYP2E1 system. It is likely that components of both models contribute to the site-specific, CNS neurotoxicity associated with CAC, but this remains largely unresolved.

Effect of acute alcohol intoxication on the opioid system in humans

We investigated the possible relations between the endogenous opioid system and acute alcoholic intoxication in 21 subjects, of whom 13 were drinkers who came to the emergency service with evident symptoms of drunkenness, and 8 were nondrinkers who consumed 1 g alcohol per kg body weight over a short period. Different patterns of changes were found in the two groups for plasma concentrations of beta-endorphin and adrenocorticotropic hormone. In drinkers, plasma levels of both substances increased, whereas in nondrinkers both concentrations decreased, the declines being especially notable 15, 30, and 45 min after ingestion. We found no differences between the two groups in plasma cortisol concentrations. The different levels of these substances may reflect differences in drinking behavior between the two groups.

Medical manifestations of alcoholism in the elderly

Alcoholism may lead to a great many physical and mental problems in individuals of any age. Elderly alcoholics often have additional problems resulting from the interaction of age related changes in physiology and "heavy" alcohol intake. Some of the more important problems are: Impairment of the immune system with decreased ability to deal with infection or cancer. Increased incidence of hypertension, cardiac arrhythmia, myocardial infarction, and cardiomyopathy. Increased incidence of stroke. Alcohol dementia. Increased incidence of esophageal and other cancers. Cirrhosis and other liver disease. Malnutrition. There seems to be no area in which even moderate alcohol intake is of definite benefit, and some areas in which even small amounts are detrimental.

Chronic alcoholization alters the expression of 5-HT1A and 5-HT1B receptor subtypes in rat brain

The expression of central 5-HT1A and 5-HT1B receptors was studied in several brain areas of rats subjected to a 2-week period of chronic alcoholization, followed by 18 h withdrawal. Quantitative autoradiography indicated that the ethanol treatment provoked an increase (approximately +30%) in the labeling by [3H]8-hydroxy-2-(di-n-propylamino)tetralin ([3H]8-OH-DPAT) and [3H]N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide ([3H]WAY-100635) of 5-HT1A autoreceptors in the dorsal raphe nucleus, accompanied by a concomitant decrease in the labeling of postsynaptic 5-HT1A receptors in the hippocampus (approximately -20%), anterior (approximately -30%) and posterior (approximately -32%) cortices. These changes were associated with a tendency toward an increase and decrease in 5-HT1A mRNA levels in the anterior raphe area and hippocampus, respectively, suggesting that the changes observed are due to modifications in 5-HT1A receptor protein synthesis. The autoradiographic labeling of 5-HT1B receptors by serotonin-O-carboxymethylglycyl[125I]iodotyrosinamide ([125I]GTI) was found to increase (+55%) in the globus pallidus of alcoholized rats. Interestingly, a significant increase (+57%) in 5-HT1B receptor mRNA levels was observed in the striatum, which contains cell bodies of neurons projecting into the globus pallidus. These data suggest that altered sensitivity of chronically alcoholized rats to 5-HT1A and 5-HT1B receptor ligands may result from alcohol-induced changes in the transcription of the genes encoding these receptors.

Eysenck's personality dimensions and sex steroids in male abstinent alcoholics and nonalcoholics: an exploratory study

This study investigated the relationship between alcoholics' personality characteristics [as indexed by the Eysenck Personality Questionnaire (EPQ)] and sex steroid levels. Three serum samples were drawn over a 90-min period in 58 inpatient male alcoholics (mean 33 days sober) and 33 non-alcoholic controls. The EPQ was administered at approximately the same point in the treatment process. Replicating previous work, we found alcoholics scored significantly higher on the Neuroticism and Psychoticism scales of the EPQ than controls. Alcoholics also had higher levels of estradiol and total testosterone than controls, which may be reflective of a biological rebound or characteristic premorbid levels. A significant positive correlation was found between testosterone and extroversion in controls, but not in alcoholics. Alcoholics showed a positive correlation between estradiol and neuroticism and a negative relationship between estradiol and extroversion. The results suggest that (a) 'normal' hormone-personality relationships are disrupted in male alcoholics, and b) personality and psychological changes consistent with the physical feminization syndrome may occur in male alcoholics.

Zinc deficiency and corticosteroids in the pathogenesis of alcoholic brain dysfunction--a review

Chronic alcoholism is associated with hypercortisolemia and low serum zinc (Zn). Hypercortisolemia could be responsible for alcoholic cerebral atrophy and is also associated with enhanced NMDA neurotoxicity. It is hypothesized that low brain Zn, noted in chronic alcoholics, enhances NMDA excitotoxicity and ethanol withdrawal seizure susceptibility. Also, Zn deficiency can produce neuronal damage through increased free radical formation. Clinically, Zn replacement therapy may be a rational approach to the treatment of alcohol withdrawal seizures and alcohol-related brain dysfunction.

Hypothalamic-pituitary-thyroid (HPT) axis in chronic alcoholism. I. HPT axis in chronic alcoholics during withdrawal and after 3 weeks of abstinence

Thyroxine (T4), free T4 (fT4), triiodothyronine (T3), free T3 (fT3), reverse T3 (rT3), thyrotropin (TSH), thyroxine binding globulin (TBG), and T3 uptake were measured in 14 chronic alcoholics during withdrawal and after 21 days of abstinence. Results were compared with those of 16 healthy volunteers. During withdrawal, the fT4 and fT3 concentrations were subnormal, whereas the respective protein-bound fractions were normal. T4, T3, and TBG increased during the abstinence period, T3 and TBG being significantly higher than in normals at the second measuring time. T3 uptake values fell, but remained well within the normal range at both measuring times. During abstinence, the fT3 levels remained significantly lower than in healthy subjects. rT3 concentrations decreased, but not significantly. The TSH values were normal throughout. These results showed numerous abnormalities in the hypothalamic-pituitary-thyroid axis in alcoholics, the reasons for which are as yet unclear. The following possible interpretations are suggested: 1. The abnormally low serum fT3 and fT4 levels during withdrawal might reflect an increase in tissue uptake. 2. The increases in T4--and partly those in T3--during abstinence seem to reflect increased binding by TBG, the level of which rose markedly for reasons as yet unknown. 3. If increases in TBG during abstinence are taken into account, the decreases in rT3 concentrations may reach the level of statistical significance. These falls in rT3 concentrations may reflect an increase in rT3 metabolization (deiodination) in various tissues, including the CNS, leading to a reduction in serum rT3 bioavailability. 4. Factors such as liver disease, protein caloric malnutrition, and "psychological stress" do not fully explain all these abnormalities. A direct effect of ethanol on intracellular thyroid hormone metabolism and/or function seems conceivable.

Extrahepatic manifestations of alcoholic liver disease

Many of the extrahepatic manifestations of alcoholic liver disease are not specific and can be seen in other forms of cirrhosis and with alcohol abuse. Features that are more common or more florid in patients with alcoholic liver disease have been discussed in this chapter. Alcoholic liver disease results in changes in many systems in the body and it is important that these are recognized and treated where appropriate.

Specific and nonspecific effects of ethanol vapor on plasma corticosterone in mice

The intent of this study was to determine whether chronic ethanol (EtOH) vapor inhalation, with or without adjunct pyrazole (PYR) administration, was stressful in mice, as defined by increases in plasma corticosterone (CORT) concentration. Mice were randomly assigned to groups differentiated both on the basis of EtOH vapor exposure and the presence or absence of PYR administration. Blood samples for blood EtOH concentration (BEC) and plasma CORT concentration were obtained from mice after 72-96 hours of treatment. Mice were sacrificed after 96 hours of treatment and body and adrenal weight determined. BEC was significantly higher in PYR-treated animals and animals treated with the higher EtOH vapor concentration. Plasma CORT was elevated in proportion to BEC; however, other nonspecific stresses, in particular that of PYR administration, also elevated plasma CORT. Nonspecific stresses associated with this protocol may reduce the generality of these observations. Nevertheless, the high correlation between BEC and plasma CORT concentration in the PYR groups indicates that, with suitable control groups, the PYR-EtOH vapor inhalation approach is viable for studies concerned with EtOH effects on hypothalamic-anterior pituitary-adrenocortical function.

Effects of acute and repeated alcohol ingestion on hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal functioning in normal males

We investigated the effects of acute and repeated alcohol ingestion on plasma levels of hormones associated with the functioning of the hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-adrenal (HPA) systems in normal males. In the first experiment, 7 normal male subjects were given ethanol (1.3 g/kg) in the form of a 43% alcohol solution of whiskey and water over a 30-min period (from 19:00 h to 19:30 h); blood samples were collected 30 min and immediately before the beginning of alcohol ingestion and then at intervals of 30 min for 180 min. Blood ethanol levels rose sharply and reached their maximum at 60 min, remaining above 1.0 mg/ml until 180 min. Prolactin levels increased, reaching a peak at 60 min, gradually returning to the initial value at 180 min. Decreased testosterone levels were observed only at 30 min. Luteinizing hormone (LH), adrenocorticotrophic hormone (ACTH) and cortisol levels did not show any increases. In the second experiment, 9 normal males were given the same dose of alcohol, but this was given on 7 consecutive evenings and the hormonal changes were examined on the 1st and 7th days, only at 30 and 60 min after alcohol ingestion began (during the period that blood ethanol levels were ascending to their peak). The results on the 1st day reconfirmed the findings in the first experiment and on the 7th day, the last alcohol ingestion produced increases in prolactin levels and decreases in testosterone levels at 30 and 60 min, but did not change other hormone levels.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo studies of ethanol on prolactin and luteinizing hormone in rats and mice

The interaction of ethanol (EtOH), prolactin (Prl) and luteinizing hormone (LH) was examined in two studies. In the first study, adult male C57B1/6J mice were given a single intraperitoneal injection of either vehicle or Prl at 5, 10 and 20 mg/kg and a significant dose-related suppression of ethanol consumption was found. This injection did not cause any differences in food intake or body weight. Additionally, a 5 mg/kg dose of Prl was also given to adult male Long Evans Hooded rats and, similarly, there was a significant suppression of ethanol consumption. In a second study, when rats were given a free choice between water and 5% EtOH, three subgroups were found regarding the amount of EtOH consumption: low, medium and high. After 2 weeks of free choice, hypothalamic, but not serum Prl and LH levels, were significantly increased in EtOH-imbibing groups compared to controls. These findings suggest important interactions between EtOH consumption and ambient levels of Prl and LH.

Investigation of the role of sex hormones in alcoholics' visuospatial deficits

This study investigated whether an alcohol-related disturbance in the functioning of the hypothalamic-pituitary-gonadal axis was a factor in alcoholics' visuospatial impairment. One month detoxified male alcoholics (n = 58) performed significantly poorer than peer controls (n = 30) on a battery of visuospatial and verbal tests. Serum concentrations of testosterone, estradiol, luteinizing hormone and follicle stimulating hormone were obtained at three times during cognitive testing. Previously reported correlations in healthy young male adults between visuospatial performance with testosterone and follicle stimulating hormone concentrations were replicated in control subjects. These correlations were not significant in the alcoholics. The results suggest that chronic alcoholism may disrupt the normal relationships between the hypothalamic-pituitary-gonadal axis and cognitive functioning.

Effect of chronic ethanol consumption on postnatal development of renal (Na + K)-ATPase in the rat

Renal (Na + K)-ATPase was studied to ascertain whether it follows the pattern of adaptation of membrane-bound enzymes that are inhibited by acute ethanol exposure and develop greater activity after chronic ethanol treatment. A colony of rats was given 20 per cent (v/v) ethanol as sole drinking solution throughout gestation, lactation and following weaning. (Na + K)-ATPase and ouabain-insensitive Ca(2+)-ATPase activities were determined; regional distribution of these enzymes was assessed in renal cortex and outer medulla. Control rats drank tap water. (Na + K)-ATPase in whole homogenate of kidney increased with age in controls and ethanol-fed rats, but the latter showed higher values at every age studied. Between 15 and 60 days of age, the control group showed 2-fold increases in cortex and 5-fold in outer medulla, whereas ethanol-fed rats reached a 3-fold increase in the enzyme activity in both renal regions. Ca(2+)-ATPase showed the same time course in developing kidney of both groups. Chronic ethanol treatment of adult rats resulted in an increase of (Na + K)-ATPase activity in cortex and outer medulla, but no change in other ATPases. Since an earlier maturational development of renal (Na + K)-ATPase was displayed by ethanol-fed rats, underlying mechanisms that may account for these results are discussed.

Hormone secretion stimulated by ethanol-induced cell swelling in normal rat adenohypophysial cells

Ethanol has been reported to affect endocrine functions, but its mechanism of action is unclear. To evaluate the hypothesis that cell swelling induced by ethanol permeation through the plasmalemma triggers hormone secretion, we studied the effect of ethanol on both hormone secretion and cell volume in acutely dispersed rat adenohypophysial cells under isotonic and hypertonic conditions. Isotonic ethanol caused a prompt cell swelling and an explosive secretory burst of prolactin and thyrotropin, which were proportional to the concentration of ethanol between 10 and 120 mM. The lowest effective dose of isotonic ethanol was 10 mM, which is below the plasma levels of legal intoxication (16 mM). Removal of medium Ca2+ enhanced the isotonic ethanol-induced increases in both cell volume and secretion. Hypertonic ethanol was ineffective in these effects. These data indicate that, in normal rat adenohypophysial cells, cell swelling caused by the rapid passage of ethanol through the plasmalemma is a potent mechanism for stimulating hormone secretion and this induced secretion is negatively modulated by extracellular Ca2+.

Cerebrospinal fluid levels of somatostatin, corticotropin-releasing hormone and corticotropin in alcoholism

Reduced brain and cerebrospinal fluid (CSF) levels of somatostatin, corticotropin-releasing hormone (CRH) and corticotropin (ACTH) have been reported among neuropsychiatric patients with cognitive dysfunction. Alcoholism is a disorder in which associated neuropsychiatric disorders occur. Therefore, we compared CSF levels of somatostatin, CRH and ACTH in alcoholics (n = 100) and normal controls (n = 30). There were no significant differences between the groups in concentrations of the 3 peptides. Moreover, there were no significant correlations between concentrations of the peptides in CSF and computed tomographic measures of the size of brain ventricles. There were, however, significant correlations between CSF concentrations of CRH and ACTH and between CSF concentrations of CRH and somatostatin in both the alcoholic and control groups.

Human leukocyte beta-adrenergic stimulated cyclic AMP in ethanol intoxication and withdrawal

The effects of ethanol were examined on cyclic AMP production in intact human leukocytes in vitro. In leukocytes isolated from alcohol abstinent subjects, ethanol enhances isoproterenol-stimulated and prostaglandin E1-stimulated cyclic AMP formation. Without agonist, ethanol is able to stimulate cyclic AMP production at concentrations of 160 mM and above. Leukocytes isolated from subjects undergoing alcohol detoxification showed increases in basal levels of leukocyte cyclic AMP, in isoproterenol-stimulated cyclic AMP, and in ethanol-stimulated cyclic AMP on the 2nd or 3rd day of withdrawal in comparison to the first day of withdrawal and in comparison to abstinent subjects. The data suggest that increased beta-adrenergic activity seen in alcohol withdrawal may be in part due to an increased responsiveness of beta-adrenergic stimulated cyclic AMP in tissues.

Differential regulation of anterior pituitary corticotrope function is observed in vivo but not in vitro in two lines of ethanol-sensitive mice

Anterior pituitary corticotrope function was analyzed in the long sleep (LS) and short sleep (SS) lines of mice selectively bred for differences in sensitivity to ethanol. In vivo challenge with acute ethanol or CRH administration or the stress of novel handling resulted in a more pronounced increase in serum corticosterone levels in LS mice compared with SS mice. Likewise, in vivo administration of ethanol resulted in 3-fold higher levels of anterior pituitary pro-ACTH/endorphin mRNA in LS mice compared with SS mice. However, this differential regulation of the HPA axis during in vivo analysis was not observed during in vitro studies of anterior pituitary corticotrope function. Primary cultures of LS and SS anterior pituicytes responded appropriately but equivalently to a variety of secretagogues known to stimulate anterior pituitary ACTH secretion. These secretagogues included CRH (10 nM), dibutyryl-cAMP (1 mM), vasopressin (100 nM), and phorbol 12-myristate 13-acetate (10 nM). Ethanol had no direct stimulatory effect on pituitary ACTH secretion. Quantitation of anterior pituitary corticotrope peptide biosynthesis was determined by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of extracts from [35S]methionine-labeled anterior pituitary explants and from [35S]methionine-labeled primary cultures of anterior pituitary cells. LS mice pro-ACTH/endorphin biosynthesis in pituitary explants was 2-fold greater than pro-ACTH/endorphin biosynthesis in SS mice pituitary explants. However, in culture, isolated from hypothalamic and adrenal factors, the LS anterior pituitary pro-ACTH/endorphin biosynthetic rate became equivalent to the SS anterior pituitary pro-ACTH/endorphin biosynthetic rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroendocrine consequences of alcohol abuse in women

Alcohol abuse and alcoholism are associated with a broad spectrum of reproductive system disorders. Amenorrhea, anovulation, luteal phase dysfunction, and ovarian pathology may occur in alcohol-dependent women and alcohol abusers. Luteal phase dysfunction, anovulation and persistent hyperprolactinemia have also been observed in social drinkers studied under clinical research ward conditions. The mechanisms underlying alcohol-related disruptions of the hypothalamic-pituitary-ovarian-adrenal axis are unknown. The reproductive consequences of alcohol abuse and alcoholism range from infertility and increased risk for spontaneous abortion to impaired fetal growth and development. Recent studies of alcohol's effects on pituitary gonadotropins and on gonadal, steroid and adrenal hormones in women are reviewed. Research on the acute effects of alcohol on opioid antagonist and synthetic LHRH-stimulated pituitary gonadotropins is summarized. The implications of alcohol's effects on reproductive hormones for impairment of fetal growth and development are discussed.

Studies of alpha-2-adrenoceptor function in abstinent alcoholics

Hormonal, haemodynamic and subjective psychological responses to the intravenous infusion of clonidine were investigated in nine male alcoholics who had been abstinent for 5 weeks, and were compared with those of nine healthy controls. The growth hormone response to clonidine was significantly blunted in the abstinent alcoholics. Both baseline cortisol levels and the clonidine-induced cortisol decrease were significantly greater in the alcoholics than in controls. Blood pressure, pulse rate and psychological responses to clonidine were similar in both groups. These results indicate that some aspects of alpha-2-adrenoceptor sensitivity are persistently abnormal in alcoholics at least 5 weeks into abstinence.

Naltrexone effects on pituitary and gonadal hormones in male and female rhesus monkeys

The long-acting opioid antagonist, naltrexone, stimulates LH and FSH in women during the early follicular phase of the menstrual cycle and is a new provocative test of hypothalamic-pituitary function (42,63). The acute effects of naltrexone (0.25, 0.50 and 1.0 mg/kg IV) on anterior pituitary (LH, FSH, PRL) and gonadal steroid (T or E2) hormones were studied in 7 female and 4 male rhesus monkeys (Macaca mulatta). Integrated plasma samples were collected at 20 min intervals for 60 min before and for 300 min after intravenous infusion of naltrexone over 10 min. In females studied during the early follicular phase (cycle days 1-3), naltrexone did not stimulate LH and significantly suppressed E2 (p less than 0.0003-0.0001) and FSH (p less than 0.006-0.0001). Naltrexone (0.50 and 1.0 mg/kg) also did not stimulate LH release in late follicular phase females (cycle days 10-12) when estradiol levels were in the peri-ovulatory range. FSH and E2 were significantly suppressed (p less than 0.01-0.05) after 1.0 mg/kg naltrexone, but not after 0.5 mg/kg naltrexone. However, in males all doses of naltrexone significantly stimulated LH (p less than 0.003-0.0001) and T (p less than 0.001-0.0001) but not FSH. LH increased significantly above baseline within 20 to 40 min and T increased significantly within 60 min. These gender differences in naltrexone's effects on pituitary gonadotropins and gonadal steroid hormones were unanticipated. These data are not concordant with clinical studies which report significant naltrexone stimulation of LH in men and in women during the early follicular phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Electroencephalographic activity and plasma ACTH during ethanol-induced euphoria

Covariance of brain electrical activity (EEG), plasma adrenocorticotrophic hormone (ACTH) and cortisol levels, and mood states were determined for healthy adult men during the first 2 hr after ingestion of ethanol or ethanol placebo under controlled double-blind conditions. Analysis of integrated plasma ACTH and cortisol levels at 5-min intervals, EEG power spectral analysis during consecutive 2-min epochs, and continuous assessment of mood states with a nonverbal instrumental device were carried out during the ascending phase of the blood ethanol curve. Ethanol induced rapid changes in brain electrical activity and plasma ACTH levels that were significantly correlated with subjective perception of changes in mood. The paroxysmal short epochs of euphoria associated with electroencephalographic and ACTH responses during the ascending phase of the blood ethanol curve may reflect physiological concomitants of pharmacological and behavioral reinforcers that enhance risk for perpetuation of drinking and alcohol abuse.

Effects of moderate consumption of alcoholic beverages on endocrine function in postmenopausal women. Bases for hypotheses

That alcoholic beverage consumption has not yet received attention as a variable that might influence the estrogenization of postmenopausal women is discussed within the context of the growing proportion of postmenopausal women in the population, their disease risk vis-à-vis estrogenization, and survey findings that report that the majority of postmenopausal women use alcoholic beverages to at least some degree. The available literature is reviewed concerning the effects of acute or chronic ethanol administration, alcoholic beverage consumption, or the administration of phytoestrogen-containing congeners of bourbon on the endocrine status of postmenopausal women or relevant animal models. The basic components of postmenopausal endocrine function and the factors known to affect endocrine status are presented. The importance of incorporating known endocrine-modulating factors into the design of future studies so as to maximize the detection of alcohol effects in postmenopausal women is emphasized.

Alcohol-induced pseudo-Cushing's syndrome mimicking Cushing's disease in a patient with an adrenal mass

Alcohol-induced pseudo-Cushing's syndrome is a disorder in which patients exhibit clinical and/or biochemical features similar to those in patients with Cushing's syndrome, but these features, related to alcohol abuse, may be transient and resolve during abstinence from alcohol. In most previous reports of alcohol-induced pseudo-Cushing's syndrome, detailed endocrinologic data supporting a diagnosis of Cushing's syndrome have been lacking. This report describes a patient with clinical features of Cushing's syndrome, increased plasma ACTH values, and elevated levels of basal urinary free cortisol and 17-hydroxysteroids that were not suppressed by low-dose dexamethasone but were suppressed by high-dose dexamethasone. Detailed test results were indistinguishable from those in Cushing's disease, which had been the initial diagnosis. When an occult history of alcohol abuse was discovered, the suspicion of alcohol-induced pseudo-Cushing's syndrome was raised. During an extended hospitalization and abstinence from alcohol, abnormal endocrinologic test results gradually became normal. This patient also demonstrated a further complicating feature, a left adrenal mass, which appeared to be a benign, coincidental lesion. Because of the high prevalence of alcohol abuse and the possibility that test results may be identical to those in Cushing's disease, clinicians should be familiar with this disorder to avoid misdiagnosis and inappropriate therapy.

Cushing's syndrome: update of diagnosis and management

Although considerable advances have been made in the understanding of Cushing's syndrome in the recent past, many difficulties persist in the diagnosis and management of patients with hypercortisolism. Precision in the diagnosis of Cushing's syndrome and the differentiation of its various forms have gradually improved, but a substantial number of cases have laboratory or radiologic findings that can be misleading or at least difficult to interpret. Furthermore, other conditions may mimic Cushing's syndrome and add to the diagnostic difficulties. Surgical extirpation of primary adrenal lesions that cause the hypercortisolism or of the neoplasms responsible for the ectopic production of adrenocorticotropic hormone remains the treatment of choice for these problems. Currently, transsphenoidal surgical exploration is the treatment of choice for Cushing's disease.

Cushing's syndrome

Cushing's syndrome remains one of the most challenging problems in clinical endocrinology. Cushing's disease is caused in the majority of cases by basophil pituitary microadenomas which may be successfully treated by trans-sphenoidal hypophysectomy. Treatment with metyrapone or o,p'-DDD can always induce a clinical remission but not a cure, and neurotransmitter therapy may be effective in a minority of cases. Pituitary irradiation cures about half of cases in the long-term and may be used for surgical failures. Tumours producing ectopic ACTH are frequently benign, small and occult and may produce a syndrome clinically indistinguishable from Cushing's disease. Biochemical investigations cannot absolutely distinguish pituitary from ectopic sources of ACTH and therefore body CT scanning and percatheter venous sampling are essential diagnostic investigations. Tumour localization may result in resection and complete cure, although even small tumours may have a malignant potential. Adrenal tumours are readily diagnosed by plasma ACTH measurement and adrenal CT scanning. Adrenal adenomas are cured by adrenalectomy. Carcinomas may be treated by a combination of adrenalectomy, radiotherapy and o,p'-DDD, but long-term prognosis is poor.