Sex differences in sympathetic-adrenal medullary reactions induced by different stressors

Sex differences in the adrenergic response to hypoglycemic stress in human

We have found different patterns of adrenergic response to insulin-induced hypoglycemia in men and women. The differences involve the readiness of adrenergic reactivity, the magnitude of the responses, and the nature of secreted amines. In men, a strong and transient discharge of epinephrine (E) is observed in plasma, corresponding to a great increase in the urinary level of this amine in the 2 h period following insulin. In women, the adrenergic response is delayed and consists of moderately increased amounts of E and norepinephrine (NE) which persist in plasma for a longer period. From the correlations observed between urinary amount and the increase of plasmatic catecholamines after 30, 45, and 60 min, it may be assumed that urinary data may reflect the cumulative plasma levels of catecholamines in the corresponding period, but not the precise pattern of plasmatic changes. Our findings show that the differences in adrenergic behavior previously observed in men and women under the effect of psychological stress, may also be induced by a metabolic stimulus such a insulin hypoglycemia; however, women, but not men, exhibit a mild release of NE under this metabolic stress.

The etiology, diagnosis, and treatment of TMJ dysfunction-pain syndrome. Part II: Differential diagnosis

Differential diagnosis is based on the pain history in combination with the clinical findings of muscle spasm and occlusion in relation to the condylar displacement as observed in the TMJ radiographs. Most often TMJ dysfunction-pain syndrome produces symptoms that have a pattern of occurrence or can be associated with function. Neurologic, vascular, and conversion pain occur at random without a pattern of occurrence and with no relation to function. Atypical TMJ dysfunction pain can occur by itself or in combination with other unrelated pain causes. Differential diagnosis is usually aided by injections of local anesthetics and diagnostic trials of an anterior bite plate and relaxant drugs. Medical consultation is advised when a diagnosis of TMJ dysfunction-pain syndrome cannot be established. Hysterical conversion is extremely rare, although occasionally a patient may have pain of unknown origin.

Sympathoneuronal and sympathoadrenal activation during ketamine anesthesia

The effects of ketamine anesthesia (3 mg/kg i.v.) on cardiovascular parameters and noradrenaline, adrenaline and dopamine-beta-hydroxylase (DBH) activity in plasma were studied in 12 patients. At 3, 6 and 10 min after induction of anesthesia, a pronounced increase in heart rate (+28%) and in systolic and diastolic blood pressure (+28% and 17% resp.) was observed. Concomitantly noradrenaline and adrenaline concentrations increased significantly from 187 to 415 ng/l and from 97 to 271 ng/l, respectively. DBH-activity in plasma remained almost unchanged. From these results it can be concluded that the well known cardiovascular stimulant effect of ketamine is due to greatly enhanced sympatho-neuronal and sympatho-adrenal activity, presumably brought about by a central mechanism of action of the drug. Furthermore, DBH-activity in plasma appeared not to be a reliable index of sympathetic activity in man.

Effect of calculation stress on hemodynamics and plasma catecholamines before and after beta-blockade with propranolol (Inderal) and mepindolol sulfate (Corindolan)

The effect of calculation stress on hemodynamic parameters and plasma adrenalin and noradrenalin was studied in two groups of 6 male subjects, before and during beta-Blockade. One group received propranolol 15 mg i.v. and the other received mepindolol sulphate 0,5 mg i.v. There was an increase in heart rate, cardiac output and blood pressure during mental stress. A significant increase in plasma adrenalin but not in noradrenalin occurred at the same time. The stress-induced rise in HR but not that in blood pressure could be prevented by beta-receptor blockage with propranolol and mepindolol sulfate. The peripheral resistance (PR) and diastolic blood pressure in stress were even higher after propranolol than in the control study. Propranolol had no effect on the increased adrenalin concentration during stress, but it was prevented by mepindolol sulfate. There was no correlation between the increase in HR and that in adrenalin during stress, but the HR in stress and the HR reaction to infused isoproterenol were highly correlated.

Interactions between heart rate, psychomotor performance and perceived effort during physical work as influenced by beta-adrenergic blockade

Effects of a single intravenous dose of propranolol (0,25 mg/kg body weight) were examined in 15 healthy male subjects who performed three reaction-time tasks of different complexity, while pedalling at five work loads on a cycle ergometer. Comparisons between measurements after propranolol and after injection of a placebo solution showed a pronounced reduction of heart rate and an increase in catecholamine excretion following propranolol. Comparisons of psychomotor performance showed no significan difference between the propranolol and placebo conditions. Nor did self-estimates of perceived physical and task-induced efforts reveal any significant effects of propranolol. The results support the notion that heart rate is not a prominent cue for perceived effort.

Stress responses in male and female engineering students

Male and female engineering students were studies under stress induced by a congnitive-conflict task and in a control condition spent in inactivity. The results showed that (a) in the control condition the sexes did not differ in adrenaline, noradrenaline or cortisol excretion, whereas heart rate was significantly higher in the females; (b) adrenaline excretion and heart rate increased significantly in both sexes during stress; (c) the rise in adrenaline excretion was more pronounced in the males, whereas the rise in heart rate was significantly greater in the females; (d) cortisol excretion increased significantly during stress in the male group only; and (e) self-estimates of effort and performance were consistently higher and increased more over time in the males than in the females, bu these sex differences on the subjective level were not reflected in actual performance. The interaction of biological and social factors in the development of sex differences in stress reactions is discussed.

The effects of adrenaline injections on human platelet monoamine oxidase and related measures

A double-blind, placebo-controlled, cross-over study in ten normal volunteers assessed the effects of the subcutaneous administration of adrenaline on platelet MAO activity, in an attempt to replicate previous findings of increased MAO activity following adrenaline. Platelet counts, cortisol plasma concentrations, and uptake of metaraminol by the platelets were also determined to elucidate possible mechanisms of action. Blood pressure and heart rate were used as indices of the concentration of adrenaline effectively in circulation. MAO activity towards benzylamine was significantly increased by adrenaline. Non-significant increases were noted in the deamination of tyramine and tryptamine, in platelet counts, cortisol concentrations and metaraminol uptake. Increases in MAO activity were also noted early in the experimental sessions suggesting that other experimental variables such as venepuncture may affect platelet MAO activity. Possible mechanisms for this adrenaline effect are discussed and it is suggested that variables such as "arousal" and "stress" must be taken into account when interpreting clinical data on platelet MAO.