Plasma free metanephrine and normethanephrine levels correlated to plasma catecholamine after acute running in amateur runner

SummaryThe content of free-catecholamines in blood platelets is much higher than in plasma and platelet catecholamines must be taken up from plasma, since platelets lack the enzymes for catecholamine synthesis. There is some evidence that platelet catecholamine content under certain circumstances may be an integrated measure of plasma catecholamine concentrations over time. Platelet-free catecholamines were therefore assayed in 18 untreated patients with essential hypertension and in 16 normotensive control subjects. Mean platelet-free dopamine in the hypertensive group was 3.7 ± 0.4 pg/mg platelet weight, i.e. significantly less than the 6.5 ± 0.9 pg/mg found in the normotensive (p <0.005). Platelet contents of noradrenaline and adrenaline did not differ. Decreased platelet-free dopamine and unchanged platelet noradrenaline and adrenaline persisted after adjustment for increased body weight in the hypertensive group. Although the reasons for decreased platelet-free dopamine in the hypertensive group remain unknown, this finding may add to previous result showing facilitated release of granular contents from blood platelets in patients with essential hypertension. Our data do not support platelet levels of free-catecholamines to be a marker of increased sympathetic tone in essential hypertension.

Download Full-text

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

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.2001.281.5.e1029 ◽

2001 ◽

Vol 281 (5) ◽

pp. E1029-E1036 ◽

Cited By ~ 8

Author(s):

Raymond R. Russell ◽

Deborah Chyun ◽

Steven Song ◽

Robert S. Sherwin ◽

William V. Tamborlane ◽

...

Keyword(s):

Type 1 Diabetes ◽

Radionuclide Angiography ◽

Left Ventricular ◽

Cardiac Response ◽

Left Ventricular Ejection ◽

Diabetic Patients ◽

Plasma Catecholamine ◽

Ventricular Ejection Fraction ◽

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 (∼2.8 mmol/l) or euglycemic (∼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 (ΔLVEF = 11 ± 2%) and PFR [ΔPFR = 0.88 ± 0.18 end diastolic volume (EDV)/s] in diabetic subjects as well as in the nondiabetic group (ΔLVEF = 13 ± 2%; ΔPFR = 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 (ΔLVEF = 7 ± 1%) and nondiabetic (ΔLVEF = 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.

Download Full-text

Catecholamine-fuel interrelationships during exercise in fasting men

Journal of Applied Physiology ◽

10.1152/jappl.1980.48.1.109 ◽

1980 ◽

Vol 48 (1) ◽

pp. 109-113 ◽

Cited By ~ 38

Author(s):

J. M. Pequignot ◽

L. Peyrin ◽

G. Peres

Keyword(s):

Maximal Oxygen Consumption ◽

Plasma Catecholamines ◽

Plasma Free Fatty Acid ◽

Work Load ◽

Bicycle Ergometer ◽

Plasma Norepinephrine ◽

Plasma Catecholamine ◽

Adrenergic Response ◽

Response To Exercise

Adrenergic response to exercise and the relationships between plasma catecholamines and blood energetic substrates were studied in sedentary men after 15 h of fasting. Subjects pedaled a bicycle ergometer until exhaustion at a work load approximating 80% maximal oxygen consumption. Working ability was diminished by the fast (P less than 0.025). Resting plasma norepinephrine level was increased by fasting. During exercise plasma epinephrine (E) and norepinephrine (NE) concentrations were more elevated in fasting subjects than in fed subjects. Plasma catecholamine (CA) levels in fasting men correlated with blood glucose, blood lactate, and plasma glycerol concentrations. There was no significative correlation between CA and plasma free fatty acid (FFA) levels. The increased adrenergic activity in fasting subjects correlated with reduced endurance time. This study emphasizes the role of CA release, probably combined with other hormonal factors, in the mobilization of energy substrates during submaximal exercise.

Download Full-text

Intrauterine growth restriction delays surfactant protein maturation in the sheep fetus

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00226.2009 ◽

2010 ◽

Vol 298 (4) ◽

pp. L575-L583 ◽

Cited By ~ 62

Author(s):

Sandra Orgeig ◽

Tamara A. Crittenden ◽

Ceilidh Marchant ◽

I. Caroline McMillen ◽

Janna L. Morrison

Keyword(s):

Mrna Expression ◽

Plasma Cortisol ◽

Surfactant Protein ◽

Cortisol Concentration ◽

Plasma Catecholamine ◽

Fetal Sheep ◽

C Protein ◽

Intrauterine Growth ◽

Plasma Cortisol Concentration ◽

The Impact

Pulmonary surfactant is synthesized by type II alveolar epithelial cells to regulate the surface tension at the air-liquid interface of the air-breathing lung. Developmental maturation of the surfactant system is controlled by many factors including oxygen, glucose, catecholamines, and cortisol. The intrauterine growth-restricted (IUGR) fetus is hypoxemic and hypoglycemic, with elevated plasma catecholamine and cortisol concentrations. The impact of IUGR on surfactant maturation is unclear. Here we investigate the expression of surfactant protein (SP) A, B, and C in lung tissue of fetal sheep at 133 and 141 days of gestation (term 150 ± 3 days) from control and carunclectomized Merino ewes. Placentally restricted (PR) fetuses had a body weight <2 SD from the mean of control fetuses and a mean gestational PaO2<17 mmHg. PR fetuses had reduced absolute, but not relative, lung weight, decreased plasma glucose concentration, and increased plasma cortisol concentration. Lung SP-A, -B, and -C protein and mRNA expression was reduced in PR compared with control fetuses at both ages. SP-B and -C but not SP-A mRNA expression and SP-A but not SP-B or -C protein expression increased with gestational age. Mean gestational PaO2was positively correlated with SP-A, -B, and -C protein and SP-B and -C mRNA expression in the younger cohort. SP-A and -B gene expression was inversely related to plasma cortisol concentration. Placental restriction, leading to chronic hypoxemia and hypercortisolemia in the carunclectomy model, results in significant inhibition of surfactant maturation. These data suggest that IUGR fetuses are at significant risk of lung complications, especially if born prematurely.

Download Full-text

Age-associated changes of exercise-induced plasma catecholamine responses

European Journal of Applied Physiology and Occupational Physiology ◽

10.1007/bf02343803 ◽

1986 ◽

Vol 55 (3) ◽

pp. 302-306 ◽

Cited By ~ 22

Author(s):

M. Lehmann ◽

J. Keul

Keyword(s):

Plasma Catecholamine ◽

Exercise Induced

Download Full-text

Plasma Catecholamine Levels and Vascular Response in Deoxycorticosterone Acetate Hypertension of Rats

Clinical Science ◽

10.1042/cs059315s ◽

1980 ◽

Vol 59 (s6) ◽

pp. 315s-317s ◽

Cited By ~ 4

Author(s):

W. Rascher ◽

R. Dietz ◽

A. Schomig ◽

J. Weber ◽

F. Gross

Keyword(s):

Hind Limb ◽

Vascular Tone ◽

Plasma Concentrations ◽

Plasma Catecholamine ◽

Vascular Response ◽

Deoxycorticosterone Acetate ◽

Pronounced Increase ◽

Basal Plasma ◽

Noradrenaline And Adrenaline ◽

Catecholamine Levels

1. In rats with deoxycorticosterone acetate (DOCA) hypertension basal plasma concentrations of noradrenaline and adrenaline correspond to those of sham-treated controls. 2. In DOCA-treated rats frusemide caused a more pronounced increase in plasma noradrenaline than in control rats. This difference was not observed for adrenaline. 3. In the isolated perfused hind-limb preparation the sensitivity to noradrenaline was already enhanced before blood pressure was elevated. 4. These results suggest that the adrenergic vascular tone is increased in DOCA hypertension in rats.

Download Full-text