Nor-epinephrine-like and epinephrine-like substances in relation to human behavior

Sympathoneural and adrenomedullary responses to mental stress

This concept-based review provides historical perspectives and updates about sympathetic noradrenergic and sympathetic adrenergic responses to mental stress. The topic of this review has incited perennial debate, because of disagreements over definitions, controversial inferences, and limited availability of relevant measurement tools. The discussion begins appropriately with Cannon's "homeostasis" and his pioneering work in the area. This is followed by mental stress as a scientific idea and the relatively new notions of allostasis and allostatic load. Experimental models of mental stress in rodents and humans are discussed, with particular attention to ethical constraints in humans. Sections follow on sympathoneural responses to mental stress, reactivity of catecholamine systems, clinical pathophysiologic states, and the cardiovascular reactivity hypothesis. Future advancement of the field will require integrative approaches and coordinated efforts between physiologists and psychologists on this interdisciplinary topic.

Concepts of scientific integrative medicine applied to the physiology and pathophysiology of catecholamine systems

This review presents concepts of scientific integrative medicine and relates them to the physiology of catecholamine systems and to the pathophysiology of catecholamine-related disorders. The applications to catecholamine systems exemplify how scientific integrative medicine links systems biology with integrative physiology. Concepts of scientific integrative medicine include (i) negative feedback regulation, maintaining stability of the body's monitored variables; (ii) homeostats, which compare information about monitored variables with algorithms for responding; (iii) multiple effectors, enabling compensatory activation of alternative effectors and primitive specificity of stress response patterns; (iv) effector sharing, accounting for interactions among homeostats and phenomena such as hyperglycemia attending gastrointestinal bleeding and hyponatremia attending congestive heart failure; (v) stress, applying a definition as a state rather than as an environmental stimulus or stereotyped response; (vi) distress, using a noncircular definition that does not presume pathology; (vii) allostasis, corresponding to adaptive plasticity of feedback-regulated systems; and (viii) allostatic load, explaining chronic degenerative diseases in terms of effects of cumulative wear and tear. From computer models one can predict mathematically the effects of stress and allostatic load on the transition from wellness to symptomatic disease. The review describes acute and chronic clinical disorders involving catecholamine systems-especially Parkinson disease-and how these concepts relate to pathophysiology, early detection, and treatment and prevention strategies in the post-genome era.

Pheochromocytoma-induced aggression?

OBJECTIVE

To document a case of pheochromocytoma with an unusually high plasma ratio of norepinephrine to epinephrine concentrations (NE:E), and a history of violent and aggressive behavior (which has been reported to be associated with increased NE:E ratios).

METHODS

We present the history of present illness, history of aggressive behavior, and the clinical course of a man who was found to have pheochromocytoma with a remarkable catecholamine profile. We also review the literature on the relationship of catecholamine ratios to behavior.

RESULTS

A 33-year-old man presented to the emergency department with the chief complaint of palpitations and chest pain. A physical exam revealed markedly elevated blood pressure. On admission, a computed tomographic scan of the abdomen revealed a 10 by 10-cm heterogeneous mass of 20 Hounsfield units superior to the right kidney. His plasma NE:E ratio was 35, and his 24-hour urine ratio of normetanephrine to metanephrine concentrations was greater than 26. The tumor was successfully removed with laparoscopic adrenalectomy, and the histologic findings revealed benign pheochromocytoma. There was no immediate change in the patient's behavior. He was incarcerated the week after surgery, and lost to follow-up.

CONCLUSION

Primarily norepinephrine-producing pheochromocytoma may have contributed to this patient's violent and aggressive behavior. Catecholamine levels may remain elevated for 1 week following surgery. Even if this patient's norepinephrine level had dropped rapidly after removal of the pheochromocytoma, and was not elevated a week later when he was arrested, it is possible that his aggressive behavior may have been conditioned by long exposure to elevated levels of norepinephrine.

Feelings and the body: the Jamesian perspective on autonomic specificity of emotion

"What is an emotion?" William James's seminal paper in Mind (1884) proposed the idea that physiological and behavioral responses precede subjective experience in emotions that are marked by "distinct bodily expression." This notion has broadly inspired the investigation of emotion-specific autonomic nervous system activity, a research topic with great longevity. The trajectory of this literature is traced through its major theoretical challenges from the Cannon-Bard, activation, and Schachter-Singer theories, through its rich empirical history in the field of psychophysiology. Although these studies are marked by various findings, the overall trend of the research supports the notion of autonomic specificity for basic emotions. The construct of autonomic specificity continues to influence a number of core theoretical issues in affective science, such as the existence of basic or 'natural kinds' of emotion, the structure of affective space, the cognition-emotion relationship, and the function of emotion. Moreover, James's classic paper, which stimulated the emergence of psychology from philosophy and physiology in the latter nineteenth century, remains a dynamic force in contemporary emotion research.

Emotional irritation before mental stress is associated with enhanced peripheral norepinephrine

Research suggests equivocal findings on associations of catecholamines and mood. Our study investigated the associations of emotional state, blood pressure and catecholamines in 55 healthy males undergoing mental stress. We especially checked the reported link between norepinephrine (NE) and emotional irritation. Blood pressure (SBP, DBP) and heart rate (HR) were continuously monitored. NE and epinephrine (EPI) were measured before, after, and 20 minutes after stress. Participants were divided into irritated versus non-irritated and anxious versus non-anxious subjects by median split on their baseline questionnaires. The task elicited significant cardiovascular, hormonal, and psychological stress responses. NE levels were significantly correlated with irritation before stress. Irritated subjects showed significantly higher DBP and NE than non-irritated subjects. The higher NE and DBP levels in the irritated participants suggest detrimental psycho-physiological interrelations promoting the development of stress-mediated cardiovascular diseases. Heightened emotional irritation before stress may be regarded as a psychological risk factor.

Anger and fear: Separable effects of emotion and motivational direction on somatovisceral responses

We studied whether emotion (anger vs. fear) and motivational direction (approach vs. withdrawal) have specific, separable, and independent somatovisceral response patterns. Imagination scripts about soccer game episodes with crossed Emotion x Motivational Direction content resulting in four experimental groups were presented to a total of N = 118 active soccer players. Self-reports reflected the emotion but not the motivational direction induction. Univariate and multivariate analyses of 24 somatovisceral variables and 2 a priori defined summary variables showed that anger and fear had specific response profiles with effect sizes correlating r = 0.53 with the respective effect sizes from a previous study. Approach and withdrawal profiles varied only in intensity. Emotion and motivational direction did not interact and had independent somatovisceral effects. Results suggest that anger and fear have separate underlying neurobiological organizations each capable of bi-directional motivational tuning of efferent pathways. Results support the Component Model of Somatovisceral Response Organization.

Hormonal and blood glucose responsiveness as an indicator of specific emotional arousal in type 1 diabetics

The aim of the present study was to examine, whether individual emotional arousal induced by a specific stress interview may effect growth hormone (GH), cortisol, catecholamine and blood glucose levels in diabetes patients. To test the validity of this hypothesis we subjected 18 Type 1 diabetics and 18 healthy controls to a life event interview which produces individual arousal. During this stress interview catecholamines and plasma cortisol levels showed no significant increase, whereas there was a significant increase of GH over time in both group (p < 0.04), with a trend in diabetics to have a more marked GH response than controls (p < 0.10). Blood glucose levels remained unaffected by the interview. Depressed diabetics showed significantly higher cortisol increases (p < 0.004) than non-depressed diabetics, whereas there was no difference among depressed and non-depressed controls. Depression was not associated with an increase of other hormones or blood glucose levels in both groups. The results of our study confirm specific pathways in which individual emotional arousal and depression may lead to chronic metabolic disturbances as a result of GH and cortisol hypersecretion.

Increased high affinity beta-adrenergic receptor densities and cyclic AMP responses of CD8 cells in multiple sclerosis

Beta-adrenergic receptor (beta R) density is increased on suppressor T-cells (Ts) from patients with chronic progressive multiple sclerosis (CPMS). We investigated the contribution of high-affinity (kh) beta R to cAMP responses of nongranular leukocyte subsets from CPMS patients and normal individuals (NL). CD8 beta R density was 1930 receptors/cell in CPMS compared to only 1020 receptors/cell in NL (t(18) = 2.73, P < 0.02). beta R densities on monocytes, B cells, and CD4 cells did not differ between groups. The increased density of beta R on CD8 cells in CPMS was entirely the result of an increase in the number of high affinity receptors. Basal level of cAMP in CD8 lymphocytes were 7.8 pmol/10(6) cells in CPMS and 3.5 pmol/10(6) cells in NL. Isoproterenol stimulation elevated cAMP levels in CD8 cells to 49.9 pmol/10(6) cells in CPMS patients and to 25.7 pmol/10(6) cells in NL (difference after activation: t(18) = 3.23, P < 0.005). No differences between groups were found in cAMP levels of other cell subsets. We also measured circulating catecholamine levels. Supine and standing epinephrine levels were not different between CPMS and NL. Supine norepinephrine (NE) levels were higher in CPMS (411 pg/ml) than in NL (268 pg/ml) (P < 0.03); upon standing, significant increases in NE occurred in both groups to 573 pg/ml in CPMS and to 494 pg/ml in NL. These results extend our previous findings of peripheral sympathetic dysregulation in CPMS and suggest a means whereby Ts function, hypothesized to play a role in the immune pathogenesis of CPMS, may be altered.

Psychobiology of stage fright: the effect of public performance on neuroendocrine, cardiovascular and subjective reactions

Subjective, neuroendocrine and cardiovascular functions were studied in high- and low-anxious musicians performing privately and publicly. Musicians were designated as "high-anxious" if they reported at least one episode of performance-related tremor and as "low-anxious" if they never had experienced tremor while performing in public. All musicians performed privately and publicly while measurements of subjective, neuroendocrine and cardiovascular functions were made. Ratings of effort and distress were made prior to performance. Heart rate was monitored telemetrically before, during and after performance. Urinary epinephrine, norepinephrine and cortisol were sampled after public and private performance, respectively. Situational factors influenced most measures. Epinephrine, norepinephrine, cortisol, heart rate and ratings of distress but not effort increased from private to public performance. Heart rate was higher in high- than in low-anxious musicians during public performance but similar during private performance. The increase in neuroendocrine activation from private to public performance was similar in the high- and low-anxious groups. It is concluded that heart rate is a sensitive measure of both situational and individual determinants of performance-related distress.

Plasma catecholamines and social behavior in male vervet monkeys (Cercopithecus aethiops sabaeus)

Many investigations in humans indicate that epinephrine, norepinephrine and their ratio may correlate with such traits as social competence, academic achievement, and aggression. However, the socioeconomic, dietary, and environmental confounds accompanying most human studies complicate their interpretation. Social status, aggression, and other social behaviors can be reliably assessed in nonhuman primates under conditions controlling for crucial environmental factors. If interpretation of human studies is correct, dominant and subordinate male vervet monkeys should exhibit distinctive patterns of catecholamine secretion. To test this possibility, seventeen adult male monkeys living in six stable social groups were observed for 6 months. Based on their success in agonistic events, subjects were categorized as dominant or subordinate. Alpha scores were calculated from empirically derived factors to provide a noncategorical measure of dominant behavioral style. Plasma epinephrine and norepinephrine samples obtained from anesthetized subjects did not differ between dominant and subordinate males. Alpha scores, however, distinguished high from low norepinephrine/epinephrine ratio groups. These findings are consistent with studies in humans linking high epinephrine, low norepinephrine, and social competence.

Correlations between psychological and physiological responses to acute flight phobia stress

Exposure of phobic subjects to real-life psychological stress may induce a high level of anxiety and be better than laboratory experiments for studies of physiological responses to psychological stress in human research. Therefore, by introducing natural psychological stress, i.e. actual flying in subjects with flight phobia (n = 23), the present study aimed at testing the hypothesis that there is, during mental stress, a direct relationship between the level of anxiety and the responses in the physiological variables blood pressure, heart rate and plasma catecholamines. Plasma adrenaline, heart rate, blood pressure and perceived anxiety measured by three different scales increased highly significantly during flight whereas plasma noradrenaline did not change. No direct relationship was found between the physiological and psychological variables. Thus, the physiological responses to natural psychological stress in terms of phobic anxiety may be definite, but the way the responses are related is less clear.

The autonomic differentiation of emotions revisited: convergent and discriminant validation

The convergent and discriminant validity of three models of physiological emotion specificity were compared. Forty-two female students served as subjects in a 2 (Context of emotional inductions: real-life, imagery) X 3 (Emotion: fear, anger, control) +1 (Happiness induced in real-life context) repeated measures design. The dependent measures included self-reports of emotion, Gottschalk-Gleser affect scores, back and forearm extensor EMG activity, body movements, heart period, respiration period, skin conductance, skin temperatures, pulse transit time, pulse volume amplitude, and blood volumes. Self-report data confirmed the generation of affective states in both contexts, as intended. Planned multivariate comparisons between physiological profiles established discriminant validity for fear and anger in the real-life context, whereas under imagery, emotion profiles were essentially equal. Convergent validity could not be substantiated. Implications for models of physiological specificity of emotion were discussed.

Plasma catecholamines in some airline passengers

Assuming that the act of flying may provoke mental stress and increments in plasma catecholamines, in-flight plasma catecholamines were compared in two groups of passengers: a group of ordinary passengers (Group 1, n = 15) and a group of passengers who had just completed a cognitive, behavioural treatment programme against flight phobia (Group 2, n = 13). No difference in catecholamines was observed between the groups. However, 10 of the subjects in Group 1 and 12 of the subjects in Group 2 had in-flight plasma adrenaline higher than the highest mean +2 SD (above 0.40 nmol/l) of resting plasma adrenaline observed in healthy subjects in a long series of studies previously or simultaneously done in our laboratory. Subjects in Group 2 (n = 12) showed an average decrease of 50% from in-flight to post-flight plasma adrenaline. Plasma noradrenaline values were not elevated compared to normal resting levels, but an average reduction of 24% was observed between in-flight and post-flight in Group 2. We could not detect any difference between passengers treated for flight phobia and ordinary passengers. However, in-flight plasma catecholamines, particularly adrenaline, seem to be elevated in some airline passengers of various backgrounds. The most plausible explanation seems to be the discomfort and fear some people feel when flying; however, we cannot exclude that the physiological act of flying per se increased plasma catecholamines. Relatively larger variations in plasma adrenaline compared to noradrenaline may favour the first of these two possible explanations.

Stress-induced activation of the sympathetic nervous system

Discrepancies between perceptions of internal or external circumstances and innate or acquired expectations lead to patterned stress responses involving several homeostatic systems, of which the sympathoadrenomedullary system (SAMS) is one. Severe, generalized threats such as hypoglycaemia, hypoxia, haemorrhage, circulatory collapse, and fight/flight situations elicit generalized SAMS activation, including cardiac stimulation, splanchnic, cutaneous, and renal vasoconstriction, and usually preserved skeletal muscle blood flow. Patterned sympathetic neural responses, resulting in redistribution of blood volume or changes in glandular activity, occur during orthostasis, exercise, altered environmental temperature, the postprandial state, and performance of attention-requiring tasks. In all these situations, SAMS activity is co-ordinated with that of the parasympathetic nervous system, the pituitary-adrenocortical system, and probably several neuropeptide systems. Although acute stress-induced SAMS activation can be a health hazard, the role of chronically repeated, stress-induced SAMS activation in the development of cardiovascular disease remains unclear. Benzodiazepines, beta-adrenoceptor blockers, and alpha 2-adrenoceptor agonists can attenuate effects of stress-induced SAMS activation, but pressor responses often are maintained.

Sustained urinary norepinephrine and epinephrine elevation in post-traumatic stress disorder

Urinary norepinephrine and epinephrine levels (microgram/day) were measured at two-week intervals during the course of hospitalization in the following patient groups: post-traumatic stress disorder (PTSD); major depressive disorder (MDD); bipolar I, manic (BP); paranoid schizophrenia (PS); and undifferentiated schizophrenia (US). The mean norepinephrine level during hospitalization was significantly higher in PTSD (76 +/- 10.4 micrograms/day) than in BP (60.6 +/- 8.4 micrograms/day), MDD (41.2 +/- 4.7 micrograms/day), PS (33.4 +/- 4.9 micrograms/day) and US (34.3 +/- 5.9 micrograms/day) groups, according to Duncan's multiple range test, (F(4,39) = 6.94, p less than 0.0003). The norepinephrine elevations in the PTSD group were sustained throughout hospitalization. The only other group to show mean levels in this range was the BP group in the first sample after hospital admission. This finding supports prior psychophysiological studies indicating increased sympathetic nervous system activity in PTSD patients. The mean epinephrine level during hospitalization was also significantly higher in PTSD (22.7 +/- 2.4 micrograms/day) than in MDD (13.6 +/- 1.7 micrograms/day), PS (14.7 +/- 2.4 micrograms/day), and US (18.9 +/- 1.8 micrograms/day), but not higher than in BP (21.5 +/- 2.7 micrograms/day). The relationship of epinephrine levels among diagnostic groups was sustained throughout hospitalization. It appears likely that the main underlying mechanisms for elevations of both hormones are psychological, but further work will be required to establish the exact nature of these mechanisms.

The relation of social to biological processes in disease

A common language is developing which describes how social interaction can lead to disease. There is a consensus based on forty years of psychophysiological research that emotion is the crucial driving force in a chain of events leading from psychosocial interaction to neuroendocrine changes. These changes, in turn, can induce physiological abnormalities eventually leading to pathologic changes. The emotions involved have been presented in a model in which a sympathetic adrenal-medullary effort-relaxation axis is contrasted with a pituitary adrenal-cortical elation-dejection axis. A further pituitary-gonadotropic axis for social success as opposed to low social assets is described. Although overlapping, each system can be shown to be related to a separate neuroendocrine mechanism whose activity pattern may be either exaggerated or suppressed. Social scientists like Kemper and gender psychologists like Bakan speak of separate power (agentic) and status (communion) axes. They appear to correspond broadly to the neuroendocrine mechanisms mentioned earlier. The changes induced by emotions are sufficiently powerful to regularly override the neuroendocrine feedback controls that should restore homeostasis. These overrides will either gradually or sometimes abruptly--as in cardiac arrhythmia--lead to pathophysiological changes and so to disease states, which are eventually fatal. Although social supports and social assets are successful in keeping neuroendocrine disturbances to a minimum in a healthy society, if the milieu is disordered, one's vulnerability is increased.

A review of heart-rate variability and evaluation

A review of the literature concerning heart rate and various forms of heart-rate variability and studies of behavior associated with these variables has been presented. Emphasis has been placed on the apparent discrepancies and inconsistencies reported within the literature as well as major methodological differences which make the integration of the data presented by various researchers almost impossible.

Plasma catecholamines, stress and aggression in maximum security patients

Investigations into the stress response of patients committed to a special hospital for criminally deviant offences have identified a group of sympathetically hypoactive patients who excrete more noradrenaline and less adrenaline in the urine than either the remaining hospital population or control subjects, during conditions of stresser anticipation. Further investigation of these patients has shown that similar differences in plasma catecholamines exist, and that the group of patients characterised by this imbalance tend to have been committed for the most physically violent crimes.