Catecholamine, dopamine-beta-hydroxylase and atrial natriuretic factor content in separate heart chambers of cardiomyopathic hamsters

Since previous investigations have suggested a relationship between atrial natriuretic factor (ANF) and dopamine-beta-hydroxylation, cardiomyopathic hamsters were studied for atrial and ventricular catecholamine (CA) and dopamine-beta-hydroxylase (D beta H) content as correlates to a parallel finding of markedly decreased atrial but increased ventricular ANF concentrations in these animals. It was noted that, with progressive cardiomyopathy, the reduced tissue norepinephrine (NE) content paralleled the declining D beta H activity in the atria. In the ventricles, however, the progressively-decreasing NE content was associated with an increase of D beta H. These data indicate that the NE depletion is mediated by different mechanisms in the ventricles and atria. They do not support a simple relationship between NE depletion and tissue D beta H activity or between the latter and tissue ANF concentrations.     

Oral branched-chain amino acid supplements that reduce brain serotonin during exercise in rats also lower brain catecholamines

Exercise raises brain serotonin release and is postulated to cause fatigue in athletes; ingestion of branched-chain amino acids (BCAA), by competitively inhibiting tryptophan transport into brain, lowers brain tryptophan uptake and serotonin synthesis and release in rats, and reputedly in humans prevents exercise-induced increases in serotonin and fatigue. This latter effect in humans is disputed. But BCAA also competitively inhibit tyrosine uptake into brain, and thus catecholamine synthesis and release. Since increasing brain catecholamines enhances physical performance, BCAA ingestion could lower catecholamines, reduce performance and thus negate any serotonin-linked benefit. We therefore examined in rats whether BCAA would reduce both brain tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis. Sedentary and exercising rats received BCAA or vehicle orally; tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis rates were measured 1 h later in brain. BCAA reduced brain tryptophan and tyrosine concentrations, and serotonin and catecholamine synthesis. These reductions in tyrosine concentrations and catecholamine synthesis, but not tryptophan or serotonin synthesis, could be prevented by co-administering tyrosine with BCAA. Complete essential amino acid mixtures, used to maintain or build muscle mass, were also studied, and produced different effects on brain tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis. Since pharmacologically increasing brain catecholamine function improves physical performance, the finding that BCAA reduce catecholamine synthesis may explain why this treatment does not enhance physical performance in humans, despite reducing serotonin synthesis. If so, adding tyrosine to BCAA supplements might allow a positive action on performance to emerge.     

Prostaglandins in neural crest-tumours

Prostaglandin and catecholamine concentrations were estimated in tumour tissues taken from four phaeochromocytomas and five other neural-crest tumours. Prostaglandins were found to be present in tumours both associated and non-associated with chronic diarrhoea. Prostaglandin F, as well as catecholamine, concentrations were higher in phaeochromocytomas than in the other tumours. The hypothesis has been made that while prostaglandins do not reach arterial circulation to give rise to pharmacological effects, such as chronic diarrhoea, prostaglandins F present in phaeochromocytomas may contribute to a higher catecholamine synthesis and/or release, resulting in a higher incidence of hypertension associated with these tumours.     

Cardiac responses to insulin-induced hypoglycemia in nondiabetic and intensively treated type 1 diabetic patients

Insulin-induced hypoglycemia occurs commonly in intensively treated patients with type 1 diabetes, but the cardiovascular consequences of hypoglycemia in these patients are not known. We studied left ventricular systolic [left ventricular ejection fraction (LVEF)] and diastolic [peak filling rate (PFR)] function by equilibrium radionuclide angiography during insulin infusion (12 pmol. kg(-1). min(-1)) under either hypoglycemic (approximately 2.8 mmol/l) or euglycemic (approximately 5 mmol/l) conditions in intensively treated patients with type 1 diabetes and healthy nondiabetic subjects (n = 9 for each). During hypoglycemic hyperinsulinemia, there were significant increases in LVEF (DeltaLVEF = 11 +/- 2%) and PFR [DeltaPFR = 0.88 +/- 0.18 end diastolic volume (EDV)/s] in diabetic subjects as well as in the nondiabetic group (DeltaLVEF = 13 +/- 2%; DeltaPFR = 0.79 +/- 0.17 EDV/s). The increases in LVEF and PFR were comparable overall but occurred earlier in the nondiabetic group. A blunted increase in plasma catecholamine, cortisol, and glucagon concentrations occurred in response to hypoglycemia in the diabetic subjects. During euglycemic hyperinsulinemia, LVEF also increased in both the diabetic (DeltaLVEF = 7 +/- 1%) and nondiabetic (DeltaLVEF = 4 +/- 2%) groups, but PFR increased only in the diabetic group. In the comparison of the responses to hypoglycemic and euglycemic hyperinsulinemia, only the nondiabetic group had greater augmentation of LVEF, PFR, and cardiac output in the hypoglycemic study (P < 0.05 for each). Thus intensively treated type 1 diabetic patients demonstrate delayed augmentation of ventricular function during moderate insulin-induced hypoglycemia. Although diabetic subjects have a more pronounced cardiac response to hyperinsulinemia per se than nondiabetic subjects, their response to hypoglycemia is blunted.     

Prostaglandins in neural crest-tumours

Prostaglandin and catecholamine concentrations were estimated in tumour tissues taken from four phaeochromocytomas and five other neural-crest tumours. Prostaglandins were found to be present in tumours both associated and non-associated with chronic diarrhoea. Prostaglandin F, as well as catecholamine, concentrations were higher in phaeochromocytomas than in the other tumours. The hypothesis has been made that while prostaglandins do not reach arterial circulation to give rise to pharmacological effects, such as chronic diarrhoea, prostaglandins F present in phaeochromocytomas may contribute to a higher catecholamine synthesis and/or release, resulting in a higher incidence of hypertension associated with these tumours.     

Prostaglandins in neural crest-tumors.

Prostaglandin and catecholamine concentrations were estimated in tumour tissues taken from four phaeochromcytomas and five other neural-crest tumours. Prostaglandins were found to be present in tumours both associated and non-associated with chronic diarrhoea. Prostaglandin F, as well as catecholamine, concentrations were higher in phaeochromocytomas than in other tumours. The hypothesis has been made that while prostaglandins do not reach arterial circulation to give rise to pharmacological effects, such as chronic diarrhoea, prostaglandins F present in phaeochromocytomas may contribute to a higher catecholamine synthesis and/or release, resulting in a higher incidence of hypertension associated with these tumours.     

Heart rate and plasma catecholamines during 24 h of everyday life in trained and untrained men.

Physical training decreases resting heart rate as well as heart rate and catecholamine responses to ordinary physical activity and mental stress. These effects have been speculated to diminish cardiac morbidity. However, the sparing of heartbeats and catecholamine production might be outweighed by exaggerated responses during training sessions. To elucidate this issue, heart rate was measured continuously and plasma catecholamine concentrations were measured frequently during 24 h of ordinary living conditions in seven endurance-trained athletes (T) and eight sedentary or untrained (UT) young males. T subjects had lower heart rates than UT subjects during sleep and during nontraining awake periods. However, because of the increase during training, the total 24-h heartbeat number did not differ between groups (107,737 +/- 3,819 for T vs. 113,249 +/- 6,879 for UT, P = 0.731). Neither during sleep nor during awake nontraining periods were catecholamine levels lower in T than in UT subjects. Peak catecholamine levels during exercise in T were much higher than peak levels in UT subjects, and 24-h average epinephrine and norepinephrine concentrations were twice as high. We concluded that in highly trained athletes the total number of heartbeats per day is not decreased and the catecholamine production is, in fact, increased.     

Catecholamine concentrations in plasma and organs of the fetal guinea pig during normoxemia, hypoxemia, and asphyxia

To examine the responses of the sympatho-adrenal system to reduced oxygen supply we studied plasma and tissue concentrations of catecholamines during normoxemia, hypoxemia, and asphyxia in 22 fetal guinea pigs near term. Fetal blood was obtained by cardiopuncture in utero under ketamine/xylazine-anesthesia. Catecholamines were determined in plasma and tissue of 15 organs and 14 brain parts by HPLC-ECD. During normoxemia (SO2 54 +/- 4 (SE) %, pH 7.36 +/- 0.02, n = 5) plasma catecholamine levels were low (norepinephrine 447 +/- 53, epinephrine 42 +/- 12, dopamine 44 +/- 6 pg/ml). During hypoxemia (SO2 27 +/- 3%, pH 7.32 +/- 0.01, n = 6) and asphyxia (SO2 24 +/- 2%, pH 7.23 +/- 0.02, n = 11) tissue catecholamine concentrations changed with changing blood gases and with increasing plasma catecholamines. Norepinephrine concentrations increased in both skin and lung and decreased in liver, pancreas, and scalp; those of epinephrine increased in the heart, lung liver, and scalp and decreased in the adrenal. There were only minor changes in brain catecholamine concentrations except for a 50% reduction in dopamine in the caudate nucleus. Concentrations of dopamine catabolite 3,4-dihydroxyphenylacetic acid decreased in many brain parts, suggesting that cerebral catecholamine metabolism was affected by hypoxemia and asphyxia. We conclude that the sympatho-adrenal system of fetal guinea pigs near term is mature and that its stimulation by reduced fetal oxygen supply leads to changes in both plasma and tissue catecholamine concentrations.     

心肌酶谱、动态心电图及冠状动脉CT血管造影诊断嗜铬细胞瘤儿茶酚胺性心脏损害价值研究

摘要 目的：探讨心肌酶谱、动态心电图及冠状动脉CT血管造影诊断嗜铬细胞瘤儿茶酚胺性心脏损害的临床价值。方法：收集2013年1月-2020年4月在我院诊断为嗜铬细胞瘤患者114例,其中嗜铬细胞瘤儿茶酚胺性心脏损害的患者27例。所有患者均完善术前常规检查（血常规、胸片、动态心电图）、心肌酶谱、心脏超声、冠状动脉CTA等临床资料,并收集患者一般临床资料,如血压、临床症状等。结果：114例嗜铬细胞瘤患者中,27例患者存在嗜铬细胞瘤儿茶酚胺性心脏损害。嗜铬细胞瘤儿茶酚胺性心脏损害患者一般临床资料与嗜铬细胞瘤无儿茶酚胺性心脏损害的患者差异无统计学意义（P＞0.05）。嗜铬细胞瘤儿茶酚胺性心脏损害以高血压为主要表现,临床症状表现多样,可伴有头痛、心悸、多汗三联征表现。114例患者中,26例患者出现心肌酶谱升高,36例患者存在不同程度的心电图异常、24例患者冠状动脉CTA异常,嗜铬细胞瘤儿茶酚胺性心脏损害患者在心肌酶谱、动态心电图及冠状动脉CTA异常例数与嗜铬细胞瘤无儿茶酚胺性心脏损害患者中差异均有统计学意义（P＜0.05）。114例患者中心肌酶谱或心电图或冠状动脉CTA异常的患者总共56例,其中嗜铬细胞瘤儿茶酚胺性心脏损害患者23例,嗜铬细胞瘤无儿茶酚胺性心脏损害患者有33例,差异有统计学意义（P＜0.05）。嗜铬细胞瘤儿茶酚胺性心脏损害患者中,心律失常最为常见。结论：嗜铬细胞瘤儿茶酚胺性心脏损害患者心肌酶谱、动态心电图及冠状动脉CTA均可存在异常表现,但特异性、敏感性不高,三者同时综合分析可以提高临床诊断。     

Lateralization of catecholaminergic and behavioral response to cerebral infarction in the rat.

The effects of left middle cerebral artery ligation on brain catecholamine concentrations and behavior were compared with those effects of right middle cerebral artery ligation which have previously been reported. Although the lesion caused by middle cerebral artery ligation appeared to be identical on the two sides, the animals with left hemispheric lesion showed no postoperative change in either mean spontaneous 24 hour activity or mean catecholamine concentrations in several areas of the brain. In marked contrast, as we have previously reported and was confirmed in the present study, the animals with a right hemispheric infarct are hyperactive for about 2 to 3 weeks after surgery and there is a significant decrease in mean norepinephrine concentrations in several brain regions. These studies have demonstrated a remarkable asymmetry in the behavioral and biochemical response to cerebral cortical infarction. It is uncertain whether this asymmetry reflects an underlying hemispheric difference in catecholaminergic or non-catecholaminergic neurons.     

Ventricular tachycardia in the absence of structural heart disease

In up to 10% of patients who present with ventricular tachycardia (VT), obvious structural heart disease is not identified. In such patients, causes of ventricular arrhythmia include right ventricular outflow tract (RVOT) VT, extrasystoles, idiopathic left ventricular tachycardia (ILVT), idiopathic propranolol-sensitive VT (IPVT), catecholaminergic polymorphic VT (CPVT), Brugada syndrome, and long QT syndrome (LQTS). RVOT VT, ILVT, and IPVT are referred to as idiopathic VT and generally do not have a familial basis. RVOT VT and ILVT are monomorphic, whereas IPVT may be monomorphic or polymorphic. The idiopathic VTs are classified by the ventricle of origin, the response to pharmacologic agents, catecholamine dependence, and the specific morphologic features of the arrhythmia. CPVT, Brugada syndrome, and LQTS are inherited ion channelopathies. CPVT may present as bidirectional VT, polymorphic VT, or catecholaminergic ventricular fibrillation. Syncope and sudden death in Brugada syndrome are usually due to polymorphic VT. The characteristic arrhythmia of LQTS is torsades de pointes. Overall, patients with idiopathic VT have a better prognosis than do patients with ventricular arrhythmias and structural heart disease. Initial treatment approach is pharmacologic and radiofrequency ablation is curative in most patients. However, radiofrequency ablation is not useful in the management of inherited ion channelopathies. Prognosis for patients with VT secondary to ion channelopathies is variable. High-risk patients (recurrent syncope and sudden cardiac death survivors) with inherited ion channelopathies benefit from implantable cardioverter-defibrillator placement. This paper reviews the mechanism, clinical presentation, and management of VT in the absence of structural heart disease.     

Effect of trifluoperazine and calmodulin on catecholamine secretion by saponin-skinned cultured chromaffin cells

We have examined the effect of trifluoperazine on catecholamine secretion by chemically skinned, cultured adrenal chromaffin cells. These cells require only ATP and calcium for secretion. Catecholamine secretion was unaffected by the drug in the presence or absence of calcium and ATP over the range 0.1 to 10 microM. At 100 microM trifluoperazine, catecholamine release was calcium and ATP independent and represented 70-80% of the total cellular content. High concentrations of exogenous calmodulin had no effect on secretion in the presence or absence of calcium. We conclude that low concentrations of the drug have no effect on secretion, while high concentrations cause non-physiological catecholamine release.     

Handgrip-induced airway dilation in asthmatic patients with bronchoconstriction induced by MCh inhalation.

We investigated the effects of static and rhythmic handgrip on the time course of recovery of airway resistance measured with the interrupter technique (Rint) following bronchoconstriction induced by methacholine (MCh) inhalation in 17 asthmatic patients. On three separate occasions, a 100 +/- 5% increase in baseline Rint was induced by MCh inhalation. Subsequently, patients either rested [control trials (CTs)] or performed 3-min bouts of static or rhythmic handgrip. Respiratory and cardiovascular variables were continuously monitored. Rint changes were assessed at 1-min intervals for 30 min after rest and both types of handgrip. Plasma catecholamine concentrations were also determined at scheduled intervals. Bronchoconstriction increased ventilation (P < 0.01) but did not affect cardiovascular variables and plasma catecholamine concentrations. Handgrip provoked an increase in cardiovascular variables (P < 0.01) and plasma norepinephrine concentrations (P < 0.05) but caused no additional changes in ventilation. Rint only partially recovered within 30 min after CTs, whereas it consistently decreased 1 min after both handgrip paradigms and remained lower than after CTs (P always <0.01) for the whole 30-min observation period. Sympathetic activation and withdrawal of cholinergic input to the airway smooth muscle reflexly induced by activation of skeletal muscle and carotid sinus receptors may be the primary events accounting for the bronchodilator response induced by handgrip. Mediators co-released in response to sympathetic activation may also have contributed.     

Role of endogenous PACAP in catecholamine secretion from the rat adrenal gland

We elucidated the contribution of endogenous pituitary adenylate cyclase-activating polypeptide (PACAP) to neurally evoked catecholamine secretion from the isolated perfused rat adrenal gland. Infusion of PACAP (100 nM) increased adrenal epinephrine and norepinephrine output. The PACAP-induced catecholamine output responses were inhibited by the PACAP type I receptor antagonist PACAP- (6-38) (30-3,000 nM) but were resistant to the PACAP type II receptor antagonist [Lys1,Pro2,5,Ara3,4,Tyr6]-vasoactive intestinal peptide (LPAT-VIP; 30-3,000 nM). Transmural electrical stimulation (ES; 1-10 Hz) or infusion of ACh (6-200 nM) increased adrenal epinephrine and norepinephrine output. PACAP-(6-38) (3,000 nM), but not LPAT-VIP, also inhibited the ES-induced catecholamine output responses. However, PACAP-(6-38) did not affect the ACh-induced catecholamine output responses. PACAP at low concentrations (0.3-3 nM), which had no influence on catecholamine output, enhanced the ACh-induced catecholamine output responses, but not the ES-induced catecholamine output responses. These results suggest that PACAP is released from the nerve endings to facilitate the neurally evoked catecholamine secretion through PACAP type I receptors in the rat adrenal gland.     

Catecholamines and uterine activity rhythms in the pregnant rhesus macaque.

This study was designed to examine the relationship between uterine contractile rhythms with maternal plasma and amniotic fluid catecholamine concentrations in the pregnant rhesus macaque. Six chronically catheterized rhesus macaques were maintained in a vest and tether system and exposed to a 12L:12D cycle. Continuous uterine activity recordings demonstrated a contractile pattern with peak activity at 2200 h (p less than 0.05). Paired maternal plasma and amniotic fluid samples were collected at 3-h intervals for 24 h between Days 131 and 148 of gestation. Samples were analyzed for norepinephrine, epinephrine, and dopamine by HPLC. Maximum plasma concentrations across the 24-h periods for norepinephrine (633 +/- 230; mean pg/ml +/- SEM) and dopamine (378 +/- 110) were observed at 2100 h and epinephrine (408 +/- 95) at 1200 h, but these values were not significant. The maximum amniotic fluid values were 378 +/- 126, 267 +/- 190, and 556 +/- 87 pg/ml for norepinephrine, epinephrine and dopamine, respectively. However, concentrations across 24 h did not differ. Neither maternal plasma nor amniotic fluid catecholamine concentrations were correlated with uterine activity rhythms. Therefore, we conclude that the nocturnal uterine activity in the rhesus macaque is not related to maternal arterial or amniotic fluid catecholamine concentrations.     

Role of catecholamines in hypotensive response to dieting.

The effect of dieting on blood pressure and catecholamine metabolism was assessed in 11 normotensive obese women by providing first a weight-maintenance regimen high in carbohydrate and then a low-energy diet. All dietary constituents other than carbohydrate were maintained constant throughout the 18-day study. The low-carbohydrate diet led within 48 hours to a 41% fall in the urinary output of 4-hydroxy-3-methoxy mandelate and a significant fall in systolic and diastolic blood pressure. Plasma noradrenaline concentrations also fell and the hypotensive effect of the diet continued despite a maintained total body sodium. Thus the fall in blood pressure appeared to be mediated by changes in catecholamine metabolism independent of sodium intake. This may explain both the usefulness of weight reduction in hypertensive patients and the fainting that occurs in some normotensive obese subjects taking slimming regimens low in carbohydrate.     

Increased lipolysis of subcutaneous abdominal adipose tissue and altered noradrenergic activity in patients with Cushing's syndrome: an in-vivo microdialysis study

Cushing's syndrome is associated with typical central redistribution of adipose tissue. The aim of the study was to assess lipolysis and catecholamines and their metabolites in subcutaneous abdominal adipose tissue using an in-vivo microdialysis technique. Nine patients with Cushing's syndrome and nine age-, gender- and body mass index (BMI)-matched control subjects were included in the study. Local glycerol concentrations were significantly increased in subcutaneous adipose tissue of patients with Cushing's syndrome (p<0.001). Plasma noradrenaline, dihydroxyphenylglycol and dihydroxyphenylalanine were decreased in patients with Cushing's syndrome (p<0.02, p<0.05, and p<0.02, respectively). Adrenaline, noradrenaline, dihydroxyphenylglycol and dihydroxyphenylalanine concentrations in subcutaneous abdominal adipose were non-significantly higher in patients with Cushing's syndrome. In conclusion, we showed that lipolysis in subcutaneous adipose tissue of patients with Cushing's syndrome is significantly increased as compared to healthy subjects. This finding together with non-significantly increased local catecholamine concentrations in these patients suggests a possible link between increased lipolysis and catecholaminergic activity in subcutaneous adipose tissue.     

Effects of clentiazem (TA-3090) and nifedipine on basal circulating catecholamine levels and on stimulation-evoked adrenal catecholamine secretion in anesthetized dogs.

The effects of TA-3090 (clentiazem) and nifedipine on basal sympathoadrenal activity and on the adrenal medullary response during splanchnic nerve stimulation were studied in dogs anesthetized with sodium pentobarbital. Plasma concentrations of epinephrine and norepinephrine were measured in aortic and adrenal venous blood before and after acute administration of the drugs, as well as during left splanchnic nerve stimulation before and after administration of drugs. Following intravenous injections, TA-3090 (30, 100, and 300 micrograms/kg) did not affect basal circulating catecholamine levels, whereas nifedipine (10, 30, and 100 micrograms/kg) markedly increased aortic epinephrine and norepinephrine concentrations in a dose-dependent manner in correlation with progressive decreases in mean arterial pressure. The changes in aortic epinephrine and norepinephrine concentrations were inversely related to those in mean arterial pressure (r = 0.603, p < 0.01; r = 0.536, p < 0.01; respectively). In response to direct splanchnic nerve stimulation (2 Hz, 2 ms, 1 min, 12 V), adrenal venous epinephrine and norepinephrine concentrations significantly increased, with a high degree of reproducibility. The catecholamine responses to splanchnic nerve stimulation were not affected by either TA-3090 or nifedipine at any dose tested. The present results suggest that the increases in circulating catecholamine levels following nifedipine administration are due to baroreflex activation secondary to the drug-induced hypotension. The study indicates that both TA-3090 and nifedipine did not significantly affect L-type Ca2+ channels related to catecholamine release in the adrenal medulla under the present experimental conditions.     

Role of Catecholamines in the Reproduction of Romanomermis culicivorax

The relative concentrations of catecholamine in the nervous system of the entomophilic nematode Romanomermis culicivorax were measured under different experimental conditions by a glyoxylic acid-induced fluorescence procedure. A greater concentration of catecholamine was recorded in the nervous system of adult males and females than in postparasitic juveniles. A higher concentration of catecholamine occurred in adults maintained in physical contact with the opposite sex than in those maintained in isolation. Adult males maintained with females in the same aqueous medium but physically separated by a barrier displayed a greater concentration of catecholamine in their nervous systems than did males maintained in isolation, but the catecholamine fluorescence intensity of such males was less than in males allowed physical contact with females. In adult males, the fluorescence intensity of catecholamine declined progressively during and after copulation. In adult females, the intensity of catecholamine remained constant before, during, and after copulation. Catecholamine(s) may play a role in regulating copulatory behavior, egg production, or oviposition.     

Studies on experimental growth retardation in sheep. Plasma catecholamines in fetuses with small placenta

Fetal growth rate in sheep has been reduced by removal of endometrial caruncles prior to conception. Fetuses were studied between 120-140 days. When small they had much higher plasma catecholamine concentrations than normal which was closely related to plasma pH and PaO2. The increase was predominantly of noradrenaline. During hypoxia, caused by giving ewes 9% O2 and 3% CO2 in N2 to breathe, plasma catecholamine concentrations in small fetuses rose further to levels approximately three times those in normal-sized fetal sheep. Again the increase was predominantly of plasma noradrenaline. During hypoxia the cardiovascular and metabolic responses of the small fetuses were correlated closely with the changes in plasma noradrenaline.