In an attempt to determine whether myocardial catecholamines vary from season to season, their concentration in rabbits was measured throughout the whole year by the spectrophotofluorometric method. The highest concentration of cardiac catecholamine was observed in summer. Measurement of the atrial response to norepinephrine revealed no significant alteration during the entire period of the experiment.
Animals ; Catecholamines/*analysis ; Heart/*drug effects ; Myocardium/*analysis ; Norepinephrine/*pharmacology ; Rabbits ; *Seasons

The catecholamine content was examined in the myocardium of dogs subjected to hemorrhagic hypotension of 40mmHg for a duration of one to hive hours respectively. No marked changes were noticed within two hours after production of homorrhagic hypotension but a significant reduction was found at the end of three hours of hypotension. The reduction of myocardial catecholamines was progressively pronounced with the prolonging the hypotensive period over three hours. Dogs were bled rapidly to an arterial blood pressure of 40mmHg and maintained at this hypotensive level for four hours, followed by reinfusion of the withdrawn blood. Eight out of 11 dogs succumbed within l2 hours, showing a 73 per cent mortality. The myocardial catecholamines in the surviving dogs returned almost to the normal level within 12-15 hours after the blood reinfusion, while those in the dogs which succumbed showed the same low level which was produced during hemorrhagic hypotension. It was also shown that the reduced myocardial catecholamines resulting from the hypotension will not be restored immediately after the reinfusion of the withdrawn blood. When norepinephrine was infused at a rate of five to seven microgram/kg/min for an hour before the reinfusion of the withdrawn blood, five out of six dogs died within 12 hours, showing a 82 per cent mortality. This result appears to indicate that norepinephrine infusion during oligemic hypotension may hasten death or not decrease the mortality of the animals. On the other hand, when norepinephrine was infused at a rate of three microgramkg/min for an hour following reinfusion of the withdrawn blood five out of 15 dogs died, indicating a significant increase of survival rate from hemorrhagic shock. The myocardial catecholamines of surviving dogs and dogs which succumbed following the administration of norepinephrine after blood reinfusion were similar respectively to those of dogs which survived and of dogs which died after blood reinfusion without norepinephrine. When norepinephrine (3 microgramkg/min) was infused for hour following blood reinfusion in the dogs pretreated with either dibenzyline (3mg/kg) or dichloroisoproterenol (1mg/kg), the beneficial effect of norepinephrine on the survival rate from hemorrhagic shock appeared to be absent. The efficacy of norepinephrine on the survival from hemorrhagic shock was discussed on the basis of myocardial catecholamine depletion.
Animals ; Catecholamines/*metabolism ; Dogs ; Epiphyses/*embryology ; Myocardium/*metabolism ; Norepinephrine/*pharmacology ; Shock, Hemorrhagic/*drug therapy

The influence of thyroxine upon n the cardiac uptake of catecholamines was investigated in rabbits. A single injection of thyroxine(1.0m/kg) into rabbits did not affect the concentration of myocardial catecholamines. However, this dose of thyroxine greatly increased the cardiac uptake of catecholamine following injection of 2.0mg of norepinephrine as compared to that of untreated normal animals and it remained elevated for several hours. Similarly thyroxine also enhanced the accumulation of myocardial catecholamines following administration of dopa(60-80mg/kg) and epinephrine(1.0-1.5mg/kg).
Animal ; Catecholamines/metabolism* ; Epinephrine/metabolism ; Heart/drug effects* ; Male ; Myocardium/metabolism* ; Norepinephrine/metabolism ; Rabbits ; Thyroxine/pharmacology* ; Tritium

The data obtained from present experiments demonstrated that among several inhalation anesthetics, ether was the most irritable, resulting in marked irregularity of respiratory movement, and halothane depressed respiratory rate more than the other. The pulse rate and blood pressure were decreased marked1y in ether and the halothane anesthesia. the rate of beat of the isolated atria was not greately altered after anesthesia with ether or trichlore-thylene, while it was reduced after chloroform or halothane inhalation. The response of isolated atria to exogeneous norepinephrine was most prominent in the atria isolated from halothane anesthetized rabbits. Myocardial catecholamine contents were reduced uniformly after anesthesia with each anesthetics and most significantly with the halothane inhalation. From the above results, it may be concluded that the increasing cardiac activity with general inhalation anesthetics is closely related to the quantitative changes of the endogenous myocardial catecholamine contents.
Anesthesia, Inhalation/adverse effects ; Anesthetics/*toxicity ; Animals ; Catecholamines/*metabolism ; Heart/*drug effects ; Myocardium/*metabolism ; Norepinephrine/*pharmacology ; Rabbits

OBJECTIVETo study the effects of catecholamines on human preadipocyte proliferation and differentiation.

METHODSCatecholamines (epinephrine, isoprenaline and noradrenaline) were added to the culture media of human preadipocytes. The proliferation of cells, the expression of GPDH and lipid droplet accumulation in cytoplasm were observed and recorded. The functions of alpha and beta receptors were examined with adding alpha and beta receptor blockers.

RESULTSEpinephrine and isoprenaline stimulated human preadipocyte proliferation and inhibited GPDH up-regulation during differentiation. The three types of catecholamines inhibited lipid accumulation in cell differentiation. The beta-adrenoceptors played a key role during the process.

CONCLUSIONHuman preadipocytes responded to catecholamine characteristically. The result would be applicable in the study of drugs for obesity.

Adipocytes ; cytology ; drug effects ; Catecholamines ; pharmacology ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Epinephrine ; pharmacology ; Humans ; Isoproterenol ; pharmacology ; Norepinephrine ; pharmacology ; Obesity ; drug therapy ; Receptors, Adrenergic, beta ; Up-Regulation

We investigated the effect of phenylephrine (PE)- and isoproterenol (ISO)-induced cardiac hypertrophy on subcellular localization and expression of caveolin-3 and STAT3 in H9c2 cardiomyoblast cells. Caveolin-3 localization to plasma membrane was attenuated and localization of caveolin-3 to caveolae in the plasma membrane was 24.3% reduced by the catecholamine-induced hypertrophy. STAT3 and phospho-STAT3 were up-regulated but verapamil and cyclosporin A synergistically decreased the STAT3 and phospho-STAT3 levels in PE- and ISO-induced hypertrophic cells. Both expression and activation of STAT3 were increased in the nucleus by the hypertrophy. Immunofluorescence analysis revealed that the catecholamine-induced hypertrophy promoted nuclear localization of pY705-STAT3. Of interest, phosphorylation of pS727-STAT3 in mitochondria was significantly reduced by catecholamine-induced hypertrophy. In addition, mitochondrial complexes II and III were greatly down-regulated in the hypertrophic cells. Our data suggest that the alterations in nuclear and mitochondrial activation of STAT3 and caveolae localization of caveolin-3 are related to the development of the catecholamine-induced cardiac hypertrophy.
Animals ; Catecholamines/*pharmacology ; Caveolae/*metabolism ; Caveolin 3/*metabolism ; Cell Line ; Hypertrophy/metabolism ; Mitochondria/*metabolism ; Myocardium/cytology/*pathology ; Myocytes, Cardiac/cytology/*drug effects/metabolism ; Rats ; STAT3 Transcription Factor/*metabolism

OBJECTIVETo study the effect of melatonin on the gastrointestinal motility and plasma levels of the stress hormone in overtraining rats.

METHODThirty adult SD rats were randomly divided into three groups (n = 10): control group, over-training group, melatonin intervention group. 30 min before each training, rats in the control and over-training groups were fed with normal saline (15 mg/kg) once a day and 5 times per week, while rats in the melatonin intervention group were administrated with melatonin, perfusion in the intervention group (15 mg/kg). Excessive training group and melatonin intervention group rats were subjected to excessive training at 5 times a week for 6 weeks. After 6 weeks, the gastric emptying rate, small intestinal propulsion ratio and levels of plasma motilin (MTL) and calcitonin gene-related peptide (CGRP), cortisol (CORT) and catecholamines (CA) were observed in all groups.

RESULTSCompared with the control group, the gastric emptying rate, small intestinal propulsion ratio and levels of plasma MTL, CORT and CA were increased significantly (P < 0.01) while the content of CGRP was reduced (P < 0.01) in over-training group. After treated with melatonin, this trend was reversed, that was, the gastric emptying rate, small intestinal propulsion ratio and levels of plasma MTL, CORT and CA were surpressed significantly (P < 0.01) while the content of CGRP was improved obviously (P < 0.01) in over-training group.

CONCLUSIONMelatonin plays an important role in protecting gastrointestinal tract from dysfunction, in which MTL, CGRP, CORT and CA are all involved.

Animals ; Calcitonin Gene-Related Peptide ; blood ; Catecholamines ; blood ; Fatigue ; Gastrointestinal Motility ; Hydrocortisone ; blood ; Melatonin ; pharmacology ; Motilin ; blood ; Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley ; Stress, Physiological

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 probe the mechanism of EEG activation and Xingnao Kaiqiao, evaluate the actions of cinnabaris and realgar in Xingnao Kaiqiao of Angong Niuhuang pill, guess the significance of cinnabaris and realgar in specific indication treatment of Angong Niuhuang pill, and provide experimental bases for the rationality of Angong Niuhuang pill building-up.

METHODSeventy SD rats were divided into seven groups: the control, the model, the Angong Niuhuang pill (0.4 g x kg(-1)), the Angong Niuhuang pill without cinnabaris and realgar (0.32 g x kg(-1)) , the cinnabaris and realgar (0.08 g x kg(-1)), the realgar (0.04 g x kg(-1)), and the cinnabaris (0.04 g x kg(-1)). Rats in the control and model groups were given distilled water. After three days of administration, the brain damage model was made by Lipopolysaccharides (LPS) injection through caudal vein and the catecholamine (CA) and its metabolites levels in cerebral cortex, included noradrenaline (NE), adrenaline (E), 3-methocy-4-hydroxyphenylglycol (MHPG), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dopamine (DA), Homovanlic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC), were determined by high-performance liquid chromatography with electrochemical detector (HPLC-ECD). Influences of Angong Niuhuang pill, Angong Niuhuang pill without cinnabaris and realgar, cinnabaris and realgar on monoamine transmitters were observed in brain damage rats caused by LPS.

RESULTLPS could raise NE, 5-HT, 5-HIAA levels and reduce E, DOPAC levels, but had no influence on HVA, DA, MHPG levels. Angong Niuhuang pill had the trend of raising E, DOPAC levels and reducing NE level, and could reduce 5-HIAA level obviously comparing with models. But Angong Niuhuang pill without cinnabaris and realgar was different, NE level was significantly higher compared to models and Angong Niuhuang pill, DA level was also significantly higher compared to all groups. Cinnabaris and realgar had the same action trends with Angong Niuhuang pill, and separate realgar could obviously reduce 5-HT.

CONCLUSIONInfluence on CA and its metabolites levels in cerebral cortex may be one of the mechanisms of Angong Niuhuang pill's EEG activation, and cinnabaris and realgar have the same action on CA levels in cerebral cortex. The results of the present work allow us to put forward the hypothesis that cinnabaris and realgar are most likely one of the important material basis in Xingnao Kaiqiao of Angong Niuhuang pill.

Animals ; Arsenicals ; pharmacology ; Brain Injuries ; chemically induced ; metabolism ; physiopathology ; Catecholamines ; metabolism ; Cerebral Cortex ; metabolism ; physiopathology ; Drug Combinations ; Electroencephalography ; drug effects ; Lipopolysaccharides ; Male ; Medicine, Chinese Traditional ; Mercury Compounds ; pharmacology ; Norepinephrine ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Serotonin ; metabolism ; Sulfides ; pharmacology

OBJECTIVETo compare the effects of Shenfu Injection (SFI) and epinephrine (EPI) on catecholamine levels in a porcine model of prolonged cardiac arrest (CA).

METHODSAfter 8 min of untreated ventricular fibrillation, 24 Wuzhishan miniature pigs were randomly assigned to one of the three groups (n=8 per group) and received central venous injection, respectively: SFI group (1 mL/kg), EPI group (20 μg/kg EPI), and normal saline (NS) group. Cardiac output (CO), maximum rate of increase/decrease in left ventricular pressure (±dp/dt), serum levels of EPI, norepinephrine (NE), and dopamine (DA) were determined at baseline and at 0.5, 1, 2, and 4 h after restoration of spontaneous circulation.

RESULTSThe duration of cardiopulmonary resuscitation was shorter in the EPI and SFI groups than in the NS group (P<0.05). The EPI level increased significantly after restoration of spontaneous circulation (ROSC) in all three groups, and was significantly different between the EPI group and the other two groups immediately after ROSC (both P<0.01), but these differences gradually disappeared over time. There were no significant differences in NE or DA levels among the three groups, and there were no correlations between catecholamine levels and CO or dp/dt (P>0.05).

CONCLUSIONSSFI did not significantly affect endogenous catecholamine levels during cardiopulmonary resuscitation after prolonged ventricular fibrillation. However, SFI improved oxygen metabolism, and produced a better hemodynamic status compared with EPI. SFI might be a potentially vasopressor drug for the treatment of CA.

Animals ; Cardiac Output ; drug effects ; Cardiopulmonary Resuscitation ; Catecholamines ; blood ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Epinephrine ; pharmacology ; therapeutic use ; Heart Arrest ; blood ; drug therapy ; Heart Ventricles ; physiopathology ; Injections ; Lactic Acid ; blood ; Sus scrofa