Epinephrine

About: Epinephrine is a research topic. Over the lifetime, 9772 publications have been published within this topic receiving 285916 citations.

Dissociation between reactivity of the hypothalamus-pituitary-adrenal axis and the sympathetic-adrenal-medullary system to repeated psychosocial stress.

Abstract: OBJECTIVE This study investigated endocrine and autonomic stress responses after repeated psychosocial stress. A first goal of the study was to investigate whether peripheral catecholamines and cardiovascular parameters would show similar or different habituation patterns after repeated stress. The second aim was to detect possible subgroups with regard to individual habituation patterns in the hypothalamus-pituitary-adrenal (HPA) axis and monitor their respective sympathetic stress responses. METHODS Sixty-five healthy subjects (19-45 years), 38 men and 27 women, were exposed to the Trier Social Stress Test (TSST) three times with a 4-week interval between stress sessions. Adrenocorticotropic hormone (ACTH), plasma cortisol, salivary cortisol, epinephrine, norepinephrine, and heart rates were measures repeatedly before and after each stress exposure. RESULTS All endocrine measures as well as heart rates increased significantly after each of the three stress sessions (F values >16.00, all p values 5.8, p 10.00, p <.01). No such differences between high and low responders could be observed with regard to catecholamine and heart rate responses. CONCLUSIONS From these data we conclude that habituation to psychosocial stress seems to be specific for a given response system. Although HPA responses quickly habituate, the sympathetic nervous system shows rather uniform activation patterns with repeated exposure to psychosocial challenge.

Plasma catecholamines in stress and exercise.

Abstract: A technique was devised to monitor plasma catecholamines in a minimally obtrusive fashion in subjects going about their working activities. There was a disparity between plasma norepinephrine and epinephrine levels in different situations. During public speaking, epinephrine levels increase twofold, whereas during physical exercise, norepinephrine levels increase threefold. It seemed that while exercise induces a response of the sympathetic nervous system, psychological stress induces primarily an adrenal response. (JAMA243:340-342, 1980)

Epinephrine inhibits tumor necrosis factor-alpha and potentiates interleukin 10 production during human endotoxemia.

Abstract: Short-term preexposure of mononuclear cells to epinephrine inhibits LPS-induced production of TNF, whereas preexposure for 24 h results in increased TNF production. To assess the effects of epinephrine infusions of varying duration on in vivo responses to LPS, the following experiments were performed: (a) Blood obtained from eight subjects at 4-24 h after the start of a 24-h infusion of epinephrine (30 ng/kg per min) produced less TNF after ex vivo stimulation with LPS compared with blood drawn before the start of the infusion, and (b) 17 healthy men who were receiving a continuous infusion of epinephrine (30 ng/kg per min) started either 3 h (EPI-3; n = 5) or 24 h (EPI-24; n = 6) were studied after intravenous injection of LPS (2 ng/kg, lot EC-5). EPI-3 inhibited LPS-induced in vivo TNF appearance and also increased IL-10 release (both P < 0.005 versus LPS), whereas EPI-24 only attenuated TNF secretion (P = 0.05). In separate in vitro experiments in whole blood, epinephrine increased LPS-induced IL-10 release by a combined effect on alpha and beta adrenergic receptors. Further, in LPS-stimulated blood, the increase on IL-10 levels caused by epinephrine only marginally contributed to concurrent inhibition of TNF production. Epinephrine, either endogenously produced or administered as a component of sepsis treatment, may have a net antiinflammatory effect on the cytokine network early in the course of systemic infection.

Adrenal and urinary catecholamines in rats during adaptation to repeated immobilization stress.

Abstract: Adrenal and urinary catecholamine levels were measured in rats subjected to one immobilization stress or during adaptation to daily repeated immobilization. A decrease in adrenal epinephrine was apparent after 90 min of the first immobilization and persisted for 24 hr after the immobilization was terminated. Adrenal norepinephrine was not affected. Urinary epinephrine and norepinephrine (24-hr excretion) were increased by one immobilization; most of these catecholamines were excreted during the interval of immobilization. After daily repeated immobilization for 2.5 hr, “adaptation” of the adrenal medulla appeared to occur. Immediately after the ninth immobilization adrenal epinephrine was still decreased, but 24 hr later it was at the control level. After 40–350 times repeated immobilization, adrenal epinephrine was not decreased and adrenal norepinephrine was increased. Urinary excretion of epinephrine was greater in rats subjected to repeated immobilization than in unstressed or once-immobilized rats. T...