Strana 1 od 35 výsledky
Fetal sheep were thyroidectomized at 80 days' gestation and reoperated at 118-122 days for insertion of vascular catheters. The effects of hypoxaemia and intravenous tyramine infusion on plasma catecholamine concentrations, blood pressure and heart rate were then determined in experiments at 125-135
The present experiments were carried out in isolated rat hearts perfused according to the Langendorff method at a constant pressure of 10 kPa. The aim was to measure norepinephrine (NE) overflow and its deaminated metabolite dihydroxyphenylglycol (DOPEG) by changing the composition of the buffer
In acute myocardial ischemia, noradrenaline is released locally from sympathetic varicosities by a Ca(2+)-independent nonexocytotic release mechanism that is effectively suppressed by inhibitors of the neuronal noradrenaline carrier (uptake1). The purpose of the present study was to elucidate the
In the larger airways, the blood circulation forms a subepithelial (mucosal) and outer (peribronchial) microvascular network. This raises the possibility that blood flow in these two networks is regulated independently. We used hypoxemia as a stimulus to induce changes in tracheal mucosal blood flow
Exercise blunts sympathetic alpha-adrenergic vasoconstriction (functional sympatholysis). We hypothesized that sympatholysis would be augmented during hypoxic exercise compared with exercise alone. Fourteen subjects were monitored with ECG and pulse oximetry. Brachial artery and antecubital vein
Chemical sympathectomy was achieved in 8 fetal lambs in utero by daily intravenous infusion of 6-hydroxydopamine (6HD). The dose was increased progressively until a cumulative dose of 60-70 mg/kg was reached. Adequacy of adrenergic denervation was verified by the lack of any cardiovascular response
Fetal lambs treated with sheep anti-mouse nerve growth factor antibodies (anti-NGF) at 80 days gestation subsequently showed a diminished cardiovascular response to intravenous infusion of tyramine (1 mg/min over 10 min) and no significant change in plasma norepinephrine concentrations as measured
The ability of endogenous myocardial catecholamines to participate in the development of myocardial cellular alterations during a short period of severe hypoxia (30 min) was studied in isolated, Langendorff-perfused rat heart preparation, arrested by a high potassium concentration (16 mM) and
1. The mechanism of the protective action of alpha-tocopherol (vitamin E) in sustaining noradrenaline-induced responses in vascular hypoxia was investigated using pharmacological methods. 2. Four vascular spasmogenic agents, methoxamine, acetylcholine, histamine and potassium, each with a different
Hypoxia impairs body temperature regulation and abolishes the decline in skin temperature associated with cold exposure, suggesting that cutaneous vasoconstriction is impaired.
OBJECTIVE
The purpose of this study was to test the hypothesis that cutaneous vasoconstriction to intradermal tyramine, an
Effects of uptake2 inhibition by corticosterone on tyramine-induced noradrenaline (NA) overflow under control, glucose-deprivation, anoxia and anoxia with glucose-deprivation were examined in perfused rat heart. Uptake2 inhibition by corticosterone (100 microM) had no effect on the NA overflow under
OBJECTIVE
Sympathetic vasoconstriction regulates peripheral circulation and controls blood pressure, but sepsis is associated with hypotension. We evaluated whether apparent loss of sympathetic vasoconstrictor responsiveness relates to distended smooth muscles or to endotoxemia and/or
We previously observed arterial sympathetic hyperinnervation and endothelial dysfunction in the chicken embryo after exposure to chronic hypoxia. We now investigate whether changes in arterial properties could also be observed at 14-15 weeks of life. Eggs of White Leghorn chicken were incubated
Systemic hypoxia in humans evokes forearm vasodilatation despite significant reflex increases in sympathetic vasoconstrictor nerve activity and noradrenaline spillover. We sought to determine whether post-junctional alpha-adrenergic vasoconstrictor responsiveness to endogenous noradrenaline release
Moclobemide is a reversible inhibitor of monoamine oxidase (MAO) with clear preference for the A type (so-called RIMA). The enzyme inhibition shows complex kinetics, and the molecular mechanism of interaction with the enzyme is not yet clear. Moclobemide increases the extracellular concentration of