Catecholamines ; blood ; Heart Rate ; Humans ; Water Sports ; physiology

It has been well known that catecholamines (CAs) in the body, including norepinephrine (NE), epinephrine (E) and dopamine (DA), are synthesized and secreted by neurons and endocrine cells and mainly modulate visceral activities such as cardiovascular, respiratory and digestive functions. The studies over the past nearly 30 years have shown that CAs can also regulate immune function. The immunomodulation of CAs is generally considered as a role mediating the regulation of nervous and endocrine systems. However, recent studies reveal that immune cells can also synthesize CAs, which is an update of traditional concept. A classical metabolic pathway of CAs shared by the nervous and endocrine systems is present in the immune cells, i.e., the immunocytes have the enzymes for synthesis of CAs [e.g. tyrosine hydroxylase (TH)] and the enzymes for degradation of CAs [e.g. monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT)]. The endogenous CAs synthesized by immune cells can regulate many immune functions, including cellular proliferation, differentiation, apoptosis and cytokine production. These roles of the endogenous CAs may be mediated by an autocrine/paracrine pathway via relevant receptors on the immunocytes and intracellular cAMP. Intracellular oxidative mechanism may also be involved in immunoregulation of endogenous CAs in immune cells. In addition, some metabolic abnormalities of CAs in the immune cells probably induce some autoimmune diseases, such as multiple sclerosis (MS) and rheumatoid arthritis. These findings not only provide evidence for the new concept that the immune system is possible to become the third CA system other than the nervous and endocrine systems, but also extend our comprehension on functional significance of the endogenous CAs synthesized by immune cells.
Animals ; Autoimmune Diseases ; immunology ; Catecholamines ; physiology ; Humans ; Immune System ; physiology ; Lymphocytes ; immunology ; metabolism ; Monoamine Oxidase ; physiology ; Neuroimmunomodulation ; physiology ; Tyrosine 3-Monooxygenase ; physiology

No abstract available.
Adrenalectomy ; Arginine Vasopressin/diagnostic use ; Catecholamines/physiology ; Cushing Syndrome/diagnosis/*physiopathology/surgery ; Humans ; Hydrocortisone/*secretion ; Male ; Middle Aged ; Vasopressins/physiology

AIMTo explore whether endogenous catecholamine participates in the effect of interleukin-2 on the isolated heart.

METHODSThe number of premature ventricular contraction (PVC), left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure(LVEDP), heart rate (HR) and coronary flow(CF)were recorded in isolated Langendorff perfused rat hearts.

RESULTS(1) 50 U/ml IL-2 increased the PVC number, LVDP LVEDP, HR and CF. (2) Pretreatment of reserpine or propranolol abolished the cardiac effect of IL-2 at 50 U/ml, while pretreatment with phentolamine did not change the effect of IL-2. (3) 200 U/ml IL-2 increased the number of PVC,but did not increase LVDP, LVEDP, HR and CF. (4) After pretreatment of reserpine or propranolol, IL-2 failed to increase the number of PVC, but caused decrease of LVDP, HR and CF, and elevation of LVEDP.

CONCLUSIONEndogenous catecholamine mediates the arrhythmogenic, positively chronotropic and inotropic effects of IL-2. IL-2 at 200 U/ml inhibits the cardiac function in the isolated rat heart.

Animals ; Catecholamines ; physiology ; Heart ; drug effects ; physiology ; In Vitro Techniques ; Interleukin-2 ; pharmacology ; Male ; Myocardial Contraction ; drug effects ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the hormonal and metabolic responses of fetal lamb during cardiopulmonary bypass.

METHODSSix pregnant ewes underwent fetal cardiopulmonary bypasses with artificial oxygenators and roller pumps for 30 minutes, which maintained the blood gas value at the fetal physiological level. The fetal blood pressure, heart rate, pH value and blood lactate levels were monitored. The levels of catecholamine, cortisol and insulin were measured pre-bypass and then again 30 minutes later. The blood glucose and free fatty acid levels were monitored continuously during the bypass. Fetal hepatic PAS staining was also carried out.

RESULTSThere were no changes before and during the bypass in fetal blood pressure, heart rate and blood gas. However, pH values decreased and blood lactate levels increased (P < 0.05). The fetal catecholamine and cortisol levels increased significantly (P < 0.01), while the levels of insulin did not change. The blood glucose and free fatty acid levels increased at the beginning of the bypass (P < 0.01), and then gradually slowed down during the bypass. The fetal hepatic PAS staining showed that hepatic glycogen was consumed in large amounts. After 30 minutes of bypass, the fetal lamb would not survive more than 1 hour.

CONCLUSIONThe fetal lamb has a strong negative reaction to cardiopulmonary bypass.

Animals ; Blood Gas Analysis ; Blood Glucose ; analysis ; Cardiopulmonary Bypass ; adverse effects ; Catecholamines ; blood ; Fatty Acids, Nonesterified ; blood ; Fetus ; physiology ; Hemodynamics ; physiology ; Hydrocortisone ; blood ; Lactates ; blood ; Sheep

OBJECTIVETo investigate the effects of catecholamine hormone on the blood and brain of heroin addicts.

METHODSRats were divided into three groups and treated with the glucose (control group), the heroin (im) (heroin group), and the combination of the intramuscular injection of reserpine and heroin (reserpine group). Changes in the levels of the dopamine (DA), cAMP, and cGMP were detected by the radioimmunoassay (RIA) method in the blood and brain tissue.

RESULTSNo significant withdrawal symptoms were observed in the reserpine group. Compared with the control and heroin groups, the blood cAMP levels were increased by 35.36% and 15.53% in the reserpine group, respectively; the cAMP levels in the midbrain ventral tegmental area (VTA), prefrontal cortex (PFC), and hippocampus (Hipp) were increased by 24.08% & 8.53%, 15.66% & 8.13%, and 21.95% & 8.40%, respectively. While compared to the control and heroin groups, the DA levels of the PFC, Hipp, striatum, and nucleus accumbens (NAc) were significantly reduced in the reserpine group, decreasing by 74.09% & 82.86%, 81.06% & 82.23%, 91.62% & 86.55% and 84.35% & 90.63%, respectively. The concentrations of cGMP of the brain tissues in the reserpine group were lower than those in the control group. In addition, the neural electrophysiological testing showed that the electroencephalogram (EEG), electrocardiogram (ECG), and muscle spindle discharge diagram of rats in both the reserpine and heroin groups were apparently changed.

CONCLUSIONCatecholamine hormone plays an important role in heroin addiction.

Animals ; Brain ; drug effects ; metabolism ; Catecholamines ; physiology ; Cyclic AMP ; blood ; metabolism ; Cyclic GMP ; blood ; metabolism ; Dopamine ; blood ; metabolism ; Heroin Dependence ; metabolism ; physiopathology ; Male ; Rats ; Rats, Wistar

AIMTo provide further evidence for the synthesis of catecholamines (CAs) in lymphocytes and to investigate the effect of the endogenous CAs synthesized by lymphocytes on function of the lymphocytes themselves and the receptor mechanisms involved in the effect.

METHODSRT-PCR was performed to detect the expression of TH mRNA in the lymphocytes from the mesenteric lymph nodes of rats. Different concentrations of pargyline, an inhibitor of monoamine oxydase, and antagonists of alpha1-, alpha2-, beta1-, and beta2-adrenergic receptor (AR) were added to the lymphocyte cultures, and then proliferative response of the lymphocytes to mitogen concanavalin A (Con A) were measured via methyl-thiazole-tetrazolium (MTT) assay.

RESULTSThe lymphocytes could express TH mRNA, and the expression of TH mRNA was significantly higher in the Con A-activated lymphocytes than in the resting ones. The treatment of pargyline of 10(-6) and 10(-5) mol/L (not 10(-7) mol/L) notably attenuated Con A-induced lymphocyte proliferation. Beta2-AR antagonist ICI118551 (10(-7) and 10(-6) mol/L) completely blocked, but alpha1-AR antagonist corynanthine and alpha2-AR antagonist yohimbine (10(-7) and 10(-6) mol/L) partly blocked the suppressive effect of pargyline on the Con A-induced lymphocyte proliferation. Nevertheless, atenolol, an antagonist of beta1-AR, had no blocking effect on pargyline inhibition of lymphocyte proliferation.

CONCLUSIONLymphocytes have the ability to synthesize CAs and the ability is enhanced in the activated lymphocytes. The endogenous CAs synthesized by lymphocytes can inhibit T cell proliferation and the inhibition of T cells by the CAs is mediated predominantly by beta2-AR on the lymphocytes.

Animals ; Catecholamines ; biosynthesis ; physiology ; Cell Proliferation ; drug effects ; Concanavalin A ; pharmacology ; Female ; Lymphocyte Activation ; Lymphocytes ; metabolism ; Male ; Neuroimmunomodulation ; physiology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta ; physiology ; T-Lymphocytes ; cytology ; immunology ; Tyrosine 3-Monooxygenase ; genetics ; metabolism

Sympathetic arborizations act as the essential efferent signals in regulating the metabolism of peripheral organs including white adipose tissues (WAT). However, whether these local neural structures would be of plastic nature, and how such plasticity might participate in specific metabolic events of WAT, remains largely uncharacterized. In this study, we exploit the new volume fluorescence-imaging technique to observe the significant, and also reversible, plasticity of intra-adipose sympathetic arborizations in mouse inguinal WAT in response to cold challenge. We demonstrate that this sympathetic plasticity depends on the cold-elicited signal of nerve growth factor (NGF) and TrkA receptor. Blockage of NGF or TrkA signaling suppresses intra-adipose sympathetic plasticity, and moreover, the cold-induced beiging process of WAT. Furthermore, we show that NGF expression in WAT depends on the catecholamine signal in cold challenge. We therefore reveal the key physiological relevance, together with the regulatory mechanism, of intra-adipose sympathetic plasticity in the WAT metabolism.
Adipose Tissue, Beige ; cytology ; diagnostic imaging ; innervation ; metabolism ; Animals ; Catecholamines ; metabolism ; Cold Temperature ; Imaging, Three-Dimensional ; Mice ; Nerve Growth Factor ; metabolism ; Neuronal Plasticity ; Receptor, trkA ; metabolism ; Signal Transduction ; Sympathetic Nervous System ; physiology