Effects of beta-adrenoceptor-blockade on stress-induced adrenocorticotrophin release in humans

A new approach to reducing postsurgical cancer recurrence: perioperative targeting of catecholamines and prostaglandins

Surgery is a crucial intervention in most cancer patients, but the perioperative period is characterized by increased risks for future outbreak of preexisting micrometastases and the initiation of new metastases-the major cause of cancer-related death. Here we argue that the short perioperative period is disproportionately critical in determining long-term recurrence rates, discuss the various underlying risk factors that act synergistically during this period, and assert that this time frame presents an unexplored opportunity to reduce long-term cancer recurrence. We then address physiologic mechanisms that underlie these risk factors, focusing on excess perioperative release of catecholamines and prostaglandins, which were recently shown to be prominent in facilitating cancer recurrence through their direct impact on the malignant tissue and its microenvironment, and through suppressing antimetastatic immunity. The involvement of the immune system is further discussed in light of accumulating evidence in cancer patients, and given the recent identification of endogenously activated unique leukocyte populations which, if not suppressed, can destroy autologous "immune-resistant" tumor cells. We then review animal studies and human correlative findings, suggesting the efficacy of blocking catecholamines and/or prostaglandins perioperatively, limiting metastasis and increasing survival rates. Finally, we propose a specific perioperative pharmacologic intervention in cancer patients, based on simultaneous β-adrenergic blockade and COX-2 inhibition, and discuss specific considerations for its application in clinical trials, including our approved protocol. In sum, we herein present the rationale for a new approach to reduce long-term cancer recurrence by using a relatively safe, brief, and inexpensive intervention during the perioperative period.

Male gamblers have significantly greater salivary cortisol before and after betting on a horse race, than do female gamblers

Prevalence rates of gambling are influenced by gender. Among normative populations, hypothalamic-pituitary-adrenal (HPA) axis response to stress is affected by gender. However, pathological, compared to recreational, gamblers demonstrate perturbations in HPA activation in response to gambling stimuli. We examined whether there were gender differences in HPA response to gambling in a naturalistic setting among horse-race bettors and scratch-off lottery bettors. Salivary cortisol was collected from horse-race gamblers (n=32) and scratch-off lottery ticket players (n=39) before and after (0, 10, or 20 min) betting on a horse race at an off-track betting establishment. Salivary cortisol levels were significantly higher among men than among women, both prior to and following, betting on a horse race. Among women, but not men, there was a decline in salivary cortisol across time in scratch-off bettors, whereas women horse-race bettors maintained consistent low concentrations of salivary cortisol at every time point sampled. Together these data suggest that engaging in gambling may have different effects on stress responses of men, compared to women. Whether these gender differences in HPA activation contribute to gender-related differences in gambling behavior is the subject of ongoing investigation.

Inflammation and cortisol response in coronary artery disease

Atherosclerosis is characterized by chronic inflammation involving autoimmune components. The degree of inflammatory activity, as detectable both within the atherosclerotic plaque and in the circulation, is associated with plaque destabilization and atherothrombotic complications. Endogenous glucocorticoids are modulators of innate and acquired immune responses, and as such play a key role in the reciprocal interaction between neuroendocrine and immune systems. Abnormalities in hypothalamic-pituitary-adrenal axis (HPA) function have been described in several chronic inflammatory disorders, and evidence has emerged lately that HPA dysfunction may be implicated also in the pathogenesis of coronary artery disease. This review is an outline of knowledge gained so far by previous studies of glucocorticoids in coronary atherosclerosis and myocardial infarction. The results consistently point towards a dysregulated cortisol secretion that may involve a failure to contain inflammatory activity. A dysfunctional HPA axis and its possible implications for coronary artery disease progress, including the hypothetical link between stress and inflammation, are discussed.

No effect of 5-day treatment with acetylsalicylic acid (aspirin) or the beta-blocker propranolol (Inderal) on free cortisol responses to acute psychosocial stress: a randomized double-blind, placebo-controlled study

BACKGROUND

The characterization of an individual's hypothalamic-pituitary-adrenal axis stress response is a main research topic in neuropsychobiology since alterations have been causally linked to several disease states. Over the last years, several studies focused on the identification of sources of inter- and intraindividual variability, but there is still a paucity of experimental data on the effect of different pharmaceuticals on cortisol responses to acute psychological stress. Therefore, in this randomized double-blind placebo-controlled study, we investigated the effect of treatment with two popular and clinically used pharmaceuticals on stress-related cortisol responses, namely acetylsalicylic acid (aspirin), a known prostaglandin synthesis inhibitor, and the beta-blocker propranolol (Inderal), a nonselective beta-receptor antagonist.

METHODS

For 5 days, 73 healthy subjects (50 men, 23 women; mean age 47.3 +/- 7.7 years) received either a daily oral dose of 100 mg aspirin, 80 mg propranolol (Inderal), aspirin + propranolol, or placebo. After treatment, subjects were confronted with the Trier Social Stress Test, a widely-used standardized psychosocial stress protocol. Cortisol responses were measured by six saliva samples taken before and after the stress exposure.

RESULTS

Subjects showed a significant cortisol increase after stress (p < 0.0001). The four treatment groups did not differ in their cortisol responses (group effect p > 0.44; interaction p > 0.97). Additionally, controlling for gender, age, smoking status, body mass index, mean arterial blood pressure or pre-stress cortisol levels yielded similar results in the total sample as well as in the male or female subgroups, respectively.

CONCLUSION

Neither short-term treatment with aspirin nor propranolol altered the acute free cortisol response to psychological stress in healthy adults.

Pre-training administration of tianeptine, but not propranolol, protects hippocampus-dependent memory from being impaired by predator stress

Extensive research has shown that the antidepressant tianeptine blocks the adverse effects of chronic stress on hippocampal functioning. The current series of experiments extended this area of investigation by examining the influence of tianeptine on acute stress-induced impairments of spatial (hippocampus-dependent) memory. Tianeptine (10 mg/kg, ip) administered to adult male rats before, but not after, water maze training blocked the amnestic effects of predator stress (occurring between training and retrieval) on memory. The protective effects of tianeptine on memory occurred in rats which had extensive pre-stress training, as well as in rats which had only a single day of training. Tianeptine blocked stress effects on memory without altering the stress-induced increase in corticosterone levels. Propranolol, a beta-adrenergic receptor antagonist (5 and 10 mg/kg, ip), in contrast, did not block stress-induced amnesia. These findings indicate that treatment with tianeptine, unlike propanolol, provides an effective means with which to block the adverse effects of stress on cognitive functions of the hippocampus.

Impaired cortisol response to acute stressors in patients with coronary disease. Implications for inflammatory activity

OBJECTIVES

Inflammation is assumed to play a major role in the progress of atherosclerotic disease. We hypothesized that an altered hypothalamic-pituitary adrenal (HPA) axis activity was linked to a disinhibited inflammatory activity in patients with coronary artery disease (CAD).

METHODS

Thirty CAD patients were assessed 12-14 weeks after a first-time acute coronary syndrome. Serum samples were assayed for C-reactive protein (CRP) and interleukin-6. Free cortisol was measured in a 24-h urine sample and in repeated saliva samples 30 min after awakening and at bedtime. The levels of inflammatory markers and cortisol were also determined before and after standardized physical and psychological stress tests.

RESULTS

The CAD patients had a higher 24-h cortisol secretion and a flattened diurnal slope, resulting from significantly higher cortisol levels at bedtime, compared to clinically healthy controls. The levels of evening cortisol were strongly related to inflammatory markers in serum. When exposed to acute physical and psychological stressors, the CAD patients showed a significantly blunted cortisol response compared to controls. In addition, a stress-induced increase in CRP was only observed in the patient group.

CONCLUSIONS

Patients with CAD exhibited a cortisol pattern that markedly differed from controls. The data indicate that a dysfunctional HPA axis response involves a failure to contain inflammatory activity in CAD patients, thus providing a possible link between stress and inflammation in disease.

Long-term beta-adrenergic receptor blockade increases levels of the most mature thymocyte subsets in aged rats

Age-related increase in the density of thymic noradrenergic fibres and noradrenaline (NA) concentration is proposed to be associated with thymic involution and altered thymopoiesis. To test this hypothesis thymocyte differentiation/maturation and thymic structure were studied in 18-month-old male Wistar rats subjected to 14-day-long propranolol (P) blockade of beta-adrenoceptors (beta-ARs). The treatment primarily resulted in changes in the T-cell receptor (TCR)-dependent stages of thymopoiesis, which led to an increase in both the relative and absolute numbers of the most mature single positive (SP) CD4(+)CD8(-) (including cells with the CD4(+)CD25(+) regulatory phenotype) and CD4(-)CD8(+) TCRalphabeta(high) thymocytes. Accordingly, in the thymi of these rats an increase in both numerical density and absolute number of medullary thymocytes encompassing mainly the most mature SP cells was found. These findings, together with an increase in the thymocyte surface expression of the regulatory molecule Thy-1 (CD90) (implicated in negative regulation of TCRalphabeta-dependent thymocyte selection thresholds) in the same rats, may suggest increased positive/reduced negative thymocyte selection. Collectively, the results indicate that a decline in thymic efficiency in generating both conventional and regulatory T cells, and consequently in immune function, in aged rats may be, at least partly, attenuated by long-term blockade of beta-ARs with P.

Characterization of thymocyte phenotypic alterations induced by long-lasting beta-adrenoceptor blockade in vivo and its effects on thymocyte proliferation and apoptosis

Adult male Wistar rats were subjected to propranolol (P, 0.40 mg/100 g/day) or saline (S) administration (controls) over 14 days. The expression of major differentiation molecules on thymocytes and Thy-1 (CD90) molecules, which are shown to adjust thymocyte sensitivity to TCRalphabeta signaling, was studied. In addition, the sensitivity of thymocytes to induction of apoptosis and concanavalin A (Con A) signaling was estimated. The thymocytes from P-treated (PT) rats exhibited an increased sensitivity to induction of apoptosis, as well as to Con A stimulation. Furthermore, P treatment produced changes in the distribution of thymocyte subsets suggesting that more cells passed positive selection and further differentiated into mature CD4+ or CD8+ single positive (SP) TCRalphabeta(high) cells. These changes may, at least partly, be related to the markedly increased density of Thy-1 surface expression on TCRalphabeta(low) thymocytes from these rats. The increased frequency of cells expressing the CD4+25+ phenotype, which has been shown to be characteristic for regulatory cells in the thymus, may also indicate alterations in thymocyte selection following P treatment. Inasmuch as positive and negative selections play an important role in continuously reshaping the T-cell repertoire and maintaining tolerance, the hereby presented study suggests that pharmacological manipulations with beta-AR signaling, or chemically evoked alterations in catecholamine release, may interfere with the regulation of thymocyte selection, and consequently with the immune response.

Effects of propranolol on symptom and endocrine responses to pentagastrin

Intravenous injections of CCK-B agonists, such as pentagastrin, produce symptoms of panic and potent activation of the human hypothalamic-pituitary-adrenal (HPA) axis. It is unclear whether these psychological and endocrine effects are mediated by similar or independent processes. Independence is supported by prior evidence that beta-adrenergic receptor blockade attenuates cardiovascular and symptom but not vasopressin responses to CCK-4. To further explore associations between somatic, emotional and endocrine responses to CCK-B agents, and potential beta-adrenergic mediating mechanisms, symptom and endocrine responses to pentagastrin were examined after propranolol pre-treatment. Cardiovascular, symptom, and endocrine (ACTH, cortisol, epinephrine) responses to pentagastrin were measured in 16 healthy adult subjects randomly assigned to receive propranolol or placebo pre-treatment. Propranolol significantly blocked the normal cardiac acceleration produced by pentagastrin, but did not reduce panic symptom or anxiety effects. It delayed and perhaps enhanced the cortisol response. No relationship between HPA and symptom responses following pentagastrin could be detected, though pre-pentagastrin cortisol was inversely related to post-injection panic symptom intensity. Endocrine, cardiovascular and symptom responses to pentagastrin appear to be separately mediated, as they did not change in concert in response to propranolol pre-treatment, nor were they correlated with one another. The results are consistent with the presence of inhibitory beta-adrenergic mediation of the HPA axis in humans. They support the hypothesis that the HPA response to pentagastrin is not secondary to the psychological stress of its side effects.

Dehydroepiandrosterone decreases mortality rate and improves cellular immune function during polymicrobial sepsis

OBJECTIVE

Sepsis is associated with a marked depression of cellular immune function. The steroid hormone dehydroepiandrosterone (DHEA) is proposed to have immunoenhancing activities. We, therefore, investigated the effect of DHEA on the mortality rate and cellular immune functions in an experimental model of sepsis.

DESIGN

Randomized animal study.

SETTING

Level I trauma center, university research laboratory.

SUBJECTS

Male NMRI mice.

INTERVENTIONS

Mice were subjected to laparotomy (sham) or cecal ligation and puncture (CLP). Mice were treated with (sham/DHEA; CLP/DHEA) or without (sham; CLP) the steroid hormone DHEA (30 mg/kg sc). Animals were killed 48 hrs after the onset of sepsis.

MEASUREMENTS AND MAIN RESULTS

The survival rate of septic mice was determined 24 and 48 hrs after onset of sepsis. Forty-eight hours after the septic challenge, a white blood cell count was performed and serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta concentrations were monitored using ELISA. Furthermore, the delayed type of hypersensitivity (DTH) reaction was evaluated on the basis of ear pinna swelling after dinitrofluorobenzene (DNFB) administration, and clinical variables (body weight, temperature, heart rate, fluid input/output, food intake) were monitored using metabolic cages. DHEA administration improved the survival rate (87% vs. 53% after 48 hrs; p <.001). This was accompanied by a restoration of the depressed DTH reaction and a reduction in TNF-alpha serum concentrations (20.7 +/- 1.4 pg/mL vs. 32.4 +/- 6.6 pg/mL).

CONCLUSIONS

These results demonstrate that DHEA administration leads to an increased survival following a septic challenge. The immunoenhancing effect of DHEA is accompanied by a reduction of TNF-alpha release and an improved activity of T-cellular immunity. DHEA administration may, therefore, be beneficial in systemic inflammation.

Casino gambling increases heart rate and salivary cortisol in regular gamblers

BACKGROUND

Although the effects of gambling on cardiovascular parameters have been documented, no data exists describing the effect of gambling on stress hormone secretion. Our study investigated the effect of gambling on heart rate and salivary cortisol in a casino environment.

METHODS

Ten male gamblers participated in both an experimental and control session. In the experimental session, gamblers played a game of blackjack using their own money. Gamblers played cards in the same setting during the control condition; however, the game was played for accumulation of points rather than money. Heart rate and endocrine parameters were recorded at baseline, 30 min, and 60 min following commencement of each session, and again at completion of the game.

RESULTS

Heart rate increased significantly from baseline to 30 min in the experimental session and remained elevated for the remainder of the recording period. Salivary cortisol was raised at 30 min and further elevated at 60 min during gambling, then returned to control levels following completion of the game.

CONCLUSIONS

These data indicate that gambling in a "real life" situation produces increases in salivary cortisol levels that accompany increased cardiovascular activity. Such effects may contribute to the development of gambling addiction.

Reactivity and recovery from different types of work measured by catecholamines and cortisol: a systematic literature overview

OBJECTIVES

To review occupational health, laboratory, and sports literature on neuroendocrine reactivity and recovery from mental, combined mental and physical, or physical tasks.

METHODS

A systematic literature search was performed in eight databases. Studies with catecholamines or cortisol as effect variables measured in blood, urine, or saliva were included.

RESULTS

After application of inclusion and exclusion criteria, 77 studies from the initial 559 identified were taken into account. In occupational settings it was found that relatively few studies were conclusive about recovery, which formed a contrast with sports research. For reactivity and recovery up to 1 hour after performing the task, half of the studies considered physical tasks and more than two thirds showed incomplete recovery compared with baseline excretion of catecholamines and cortisol. Recovery extending to 3 days after the task was performed was often incomplete for cortisol after combined mentally and physically demanding tasks, and less often after solely mental or physical tasks. This type of recovery was more often incomplete for adrenaline (epinephrine) than for noradrenaline (norepinephrine), which was the case after mental as well as combined mental and physical tasks.

CONCLUSIONS

The results from laboratory and sports research may be transferable to some occupations, but more research is needed on the course of recovery relative to health effects in occupational settings.