Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In pentobarbital-pancuronium anesthetized open chest dogs, left ventricular pressure (LVP), first derivative of LVP (dp/dt) and left ventricular end-diastolic pressure (LVEDP) were measured by a micromanometer tipped catheter, stroke volume and cardiac output (CO) by an electromagnetic flow meter and coronary sinus blood flow (CSBF), by a thermal dilution catheter, respectively. Mean arterial pressure (mAP), mean pulmonary arterial pressure (mPAP), lead II of ECG and esophageal temperature were monitored. Blood gas, catecholamines and lactate of arterial blood and coronary sinus blood were measured and myocardial lactate extraction ratio (MCL) was calculated. As an index of contraction, maximum positive dp/dt (+dp/dt max), and as an index of relaxation, the time constant (T) of isovolumic left ventricular pressure fall were employed, respectively. Acute hypoxia was induced by the inhalation of a 5% O2-95% N2 gas mixture and arterial blood oxygen pressure was maintained between 15 and 20 mmHg. Along with the advancement of hypoxia, +dp/dt max, CO and mAP gradually increased and peaked in 5 minutes. Thereafter, these parameters began to decrease and CO fell to zero in 20 minutes. mPAP and HR slowly increased and peaked in 9 and in 12 minutes, respectively. T was progressively prolonged throughout the hypoxia. CSBF/CO ratio was increased and stayed at a high level even after CO began to decrease. MCL decreased and changed from positive values to negative ones in 5 minutes. Epinephrine and norephinephrine concentrations slowly increased and peaked in 16 minutes. A gradual decrease in the R wave, shortening of the R-R interval and lengthening of the QTc interval were observed in ECG. This study indicated that the left ventricular relaxing function was impaired earlier than contracting function by acute hypoxia and that conversion of the augmented left ventricular contractile state to the depressed one coincided with conversion of myocardial lactate extraction to its production.
 ...
PMID:[Effects of acute hypoxia on cardiovascular dynamics, myocardial metabolism and ECG in dogs]. 273 62

The effects of environmental air temperature of 6 degrees C and 26 degrees C on catecholamines (CA) and circulation were studied in eight male subjects during rest and during bicycle exercise at WOBLA for 45 min each. We found that resting at 6 degrees C increased the norepinephrine (NE) levels to the same levels as endurance exercises at 6 degrees C. The increase of CA levels was 2.5 to 3 times higher during work at 26 degrees C compared with 6 degrees C. During both rest and exercise at 6 degrees C we found a higher stroke volume of the heart and a reduced heart rate (HR) with no or only small effects on the oxygen uptake and blood lactate levels compared with 26 degrees C. Measurements of the skin temperatures showed large differences both at rest and during work; those of core temperature showed no changes at rest and a slightly more pronounced increase during work at 26 degrees C compared with 6 degrees C. The behavior of CA, plasma renin activity (PRA), plasma aldosterone (PA), and circulation were studied in 13 top class swimmers and 12 recreational swimmers during immersion into water of 27 degrees C for 10 min. The recreational swimmers were additionally immersed into water of 21 degrees C and 33 degrees C. Even immersion at 33 degrees C induced a small but significant increase of NE levels and of blood pressure (BP) values with no effect on the HR and blood lactate values. Epinephrine (EPI) showed a tendency to decrease.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of temperature and water immersion on plasma catecholamines and circulation. 305 72

To evaluate the hemodynamic effects of simultaneous nitroglycerin and epinephrine infusion following aortocoronary bypass surgery, 16 patients were monitored and studied in the early postoperative period. All patients were given intravenous nitroglycerin, epinephrine, epinephrine combined with nitroglycerin, and dobutamine in a randomized manner. The dose of pharmacologic agent was gradually increased to achieve the required circulatory response. The measured variables included heart rate (HR), central venous pressure (CVP), arterial blood pressure (BP), pulmonary artery pressure (PA), pulmonary artery wedge pressure (PAWP), cardiac output, and arterial and venous oxygen saturations. A nitroglycerin infusion at 1.1 +/- 2 micrograms/kg/min caused the PAWP to decrease by 37% (P less than or equal to .005). All other parameters were not significantly different from control. Epinephrine at a dose of 0.06 +/- 0.02 micrograms/kg/min increased the mean blood pressure by 21% (P less than or equal to .005). The rate-pressure product (RPP) and PAWP were elevated by 18% and 12%, respectively (P less than or equal to .005). Cardiac index, however, was not increased. When nitroglycerin was added to the epinephrine infusion, a PAWP increase was not seen. Also the right ventricular stroke work index was increased by 23% (P less than or equal to .01), and the left ventricular stroke work index increased by 21% (P less than or equal to .01). Dobutamine 4.8 +/- 1.0 micrograms/kg/min caused ventricular stroke work indexes to increase significantly (P less than or equal to .005). The CVP and PAWP were unchanged with this mode of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Pharmacologic support of the myocardium following aortocoronary bypass surgery: a comparative study. 308 42

To test the effect of a high dietary calcium intake on blood pressure, we fed stroke-prone spontaneously hypertensive (SHR-SP) and Wistar-Kyoto rats (WKY) diets containing (a) 0.25% Ca/0.08% Mg, (b) 4.0% Ca/0.02% Mg, and (c) 4.0% Ca/0.08% mg, beginning at 6 weeks of age. SHR-SP and WKY rats receiving 4% Ca with the lower Mg content had lower blood pressures, hypomagnesemia, and hypomagnesuria, and grew poorly. SHR-SP receiving 4% Ca and the higher Mg diet had blood pressures no different from those of rats receiving the 0.25% Ca diet, in spite of having lower body weights. Rubidium flux studies in erythrocytes were not influenced by Ca or Mg in the diets. Plasma phosphate values were moderately reduced in rats receiving 4% Ca diets. Epinephrine and norepinephrine values were higher in SHR-SP than in WKY rats. Norepinephrine increased with stress in both strains, independent of diet. Epinephrine values were lower in SHR-SP receiving the 4% Ca diets and showed less of an increase with stress compared to SHR-SP receiving the 0.25% Ca diet. After 26 weeks of diets, SHR-SP and WKY rats were given 0.9% NaCl in their drinking water. NaCl increased blood pressure in SHR-SP irrespective of Ca content of the diet. These data suggest that a high Ca diet influences Mg homeostasis and adrenal medullary function in SHR-SP. Further, SHR-SP appear resistant to any blood pressure lowering effect of Ca irrespective of NaCl intake.
 ...
PMID:Effect of high calcium diet on magnesium, catecholamines, and blood pressure of stroke-prone spontaneously hypertensive rats. 335 96

Symptoms, therapy, and outcome of 49 cases of anaphylactic reaction are presented. Epinephrine (0.5-2.0 mg) did not produce any circulatory improvement but induced severe dysrhythmias and even ventricular fibrillation. Neither epinephrine nor prednisolone (2 g) prevented shock development, neurologic sequelae, or fatal outcome. Rapid infusion of 2000 ml 50% colloid (dextran 70 or starch, m.w. 450,000) with 50% Ringer's lactate, however, reliably restored circulation within 30 min. If elevated, airway resistance dropped in conjunction with colloid administration rather than with any other drug. Impairment of the pulmonary circulation is found to be the initial feature of anaphylaxis, manifested by a rise in pulmonary vascular resistance; then stroke volume and systemic blood pressure fall as left heart filling is reduced. Many findings indicate a high blood viscosity with resulting capillary occlusion: rapid clotting; low levels of factors I, II, V, VIII, and X; low plasma protein, which may be only 50% of its normal value; thrombocytopenia; and aggregation of white blood cells with fibrin in small lung vessels. Blood and plasma vanish from the circulation and appear to be sequestered in the pulmonary capillaries as the initial response to the antigen; later, the whole body is affected. Congestion and pain in the lymph nodes indicate that the lymphatic system may also become involved. On the basis of hemoconcentration, a blood volume deficiency in the range of 30% has been calculated.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Anaphylactic shock]. 360 58

Serotonin, which is released when platelets aggregate at carotid lesions, may contribute to cerebral ischemia. Our goal was to test the hypothesis that dietary treatment of atherosclerosis reverses the augmented cerebral vasoconstrictor response to serotonin. We studied normal cynomolgus monkeys, atherosclerotic monkeys, and atherosclerotic monkeys that were fed a normal (regression) diet for 18 months. Morphometric studies indicated that the regression diet reduced intimal area in the carotid arteries by about 50-75%. Cerebral blood flow was measured with microspheres, and microvascular pressure was measured with a micropipette in pial arteries that were approximately 300 micron in diameter. Values for cerebral blood flow and arteriolar pressure were used to calculate resistance of large cerebral arteries (greater than 300 micron diameter). Infusion of serotonin produced a modest increase in the resistance of large cerebral arteries in normal monkeys. Vasoconstrictor responses to serotonin were increased more than fivefold in atherosclerotic monkeys. The major finding of the study is that dietary treatment of atherosclerosis abolishes augmented cerebral responses to serotonin.
Stroke
PMID:Cerebral vasoconstrictor responses to serotonin after dietary treatment of atherosclerosis: implications for transient ischemic attacks. 368 79

Attempts were made to define the effects of epinephrine and dobutamine on the myocardium during early reperfusion for 60 minutes following hypothermic global ischemia at a myocardial temperature of 28 degrees C for 60 minutes under cardiopulmonary bypass. Ischemia was induced by cross-clamping the dog aorta. Epinephrine (0.1 microgram/kg/min) and dobutamine (5 micrograms/kg/min) were given throughout the reperfusion period by intravenous drip infusion, a control group was treated with saline infusion. Comparison of hemodynamic parameters was made before cardiopulmonary bypass, and at 30 and 60 minutes of reperfusion. Epinephrine and dobutamine significantly increased stroke volume index, left ventricular stroke work index and tissue calcium content compared with saline, however, myocardial water content was only slightly higher in the group given saline, compared with the other two groups. Myocardial mitochondrial membranes and cristae were slightly damaged and creatine phosphate content was reduced. Ultrastructural integrity was related to myocardial tissue calcium content, with a significant negative correlation. These results suggest that epinephrine (0.1 microgram/kg/min) will improve stroke volume index and left ventricular stroke work index, as does dobutamine (5 micrograms/kg/min), however, both agents had a minimal effect on reducing myocardial morphological and biochemical integrity, although catecholamines have detrimental effects on the myocardium in early reperfusion following ischemia.
 ...
PMID:Effects of catecholamines on myocardial viability in early reperfusion following hypothermic global ischemia in dogs--comparison between epinephrine and dobutamine. 383 1

The hemodynamic effects of three different infusion rates of epinephrine (25, 50, or 100 ng X kg-1 X min-1 for 14 min) were examined in 10 normal human subjects. Ejection fraction and changes in cardiac volumes were assessed by radionuclide ventriculography. Plasma epinephrine was increased to levels that spanned the normal physiological range (178 +/- 15, 259 +/- 24, and 484 +/- 69 pg/ml, respectively). Epinephrine infusions resulted in dose-dependent increases in heart rate (8 +/- 3, 12 +/- 2, and 17 +/- 1 beats/min, mean +/- SE) and systolic pressure (8 +/- 1, 18 +/- 2, and 30 +/- 6 mmHg). Although epinephrine infusions had minimal effects on end-diastolic volume, there were significant increases in stroke volume (+26 +/- 2, 31 +/- 4, and 40 +/- 4%), ejection fraction (+0.10 +/- 0.01, 0.14 +/- 0.02 and 0.16 +/- 0.03 ejection fraction units), and cardiac output (+41 +/- 4, 58 +/- 5, and 74 +/- 1%). These increases in left ventricular performance were associated with a decreased systemic vascular resistance (-31 +/- 3, -42 +/- 2, and -48 +/- 8%). Supine bicycle exercise resulted in similar plasma epinephrine levels (417 +/- 109 pg/ml) and similar changes in stroke volume, ejection fraction, and systemic vascular resistance but greater increases in heart rate and systolic blood pressure. Since infusion-associated hemodynamic changes occurred at plasma epinephrine levels commonly achieved during many types of physical and emotional stress, epinephrine release may have an important role in regulating systemic vascular resistance, stroke volume, and ejection fraction responses to stress in man.
 ...
PMID:Hemodynamic effects of epinephrine: concentration-effect study in humans. 398 75

A study was made of the effects of different inotropic factors on mechanical tension in the left ventricular wall and in the apex of the heart and of the participation of these regions in the formation of hemodynamic characteristics. Adrenaline caused similar effects whereas CaCl2 exerted different inotropic effects on the left ventricular wall and the apex of the heart. Changes in mechanical tension of the wall correlated with variations in the pressure inside the left ventricle. Tension in the apex of the heart produced alterations in the stroke volume.
 ...
PMID:[Mechanical tension in different parts of the left ventricle of the heart exposed to inotropic factors]. 402 60

Heart output, arterial pressures, and heart rate were measured directly in conscious unrestrained eels (Anguilla australis) and responses to intra-arterial injection of adrenaline monitored. Adrenaline increased systemic vascular resistance, heart output, and cardiac stroke volume in all animals. In some cases small transient decreases in stroke volume and hence heart output were seen at the peak of the pressor response: These probably reflect a passive decrease in systolic emptying due to increased afterload on the heart. In most cases, adrenaline produced tachycardia; but two animals showed consistent and profound reflex bradycardia, which was accompanied by a concomitant increase in stroke volume such that heart output was maintained or increased slightly. The interaction of changes in heart output and systemic vascular resistance produced complex and variable changes in arterial pressure. There was no consistent pattern of changes in branchial vascular resistance. Atropine treatment in vivo revealed vagal cardio-inhibitory tone in some animals and always blocked the reflex bradycardia seen during adrenaline induced hypertension. In some animals, adrenaline injection after atropine pretreatment led to the establishment of cyclic changes in arterial pressure with a period of about 1 min (Mayer waves).
 ...
PMID:Adrenergic responses of the cardiovascular system of the eel, Anguilla australis, in vivo. 405 85


<< Previous 1 2 3 4 5 6 7 8 9 Next >>