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Biomedical subjects

G Unge

Publications and source records attributed to G Unge.

At least 37 records · Page 2Linked to original sources
PubMed1982

Defective serotonin (5-HT) transport mechanism in platelets from patients with endogenous and allergic asthma.

The kinetics of the 5-HT-uptake by platelets in platelet-rich plasma (PRP) and PRP diluted with autologous platelet-poor plasma (PRP/PPP) were determined in normal subjects, patients with asymptomatic exogenous asthma and those with symptomatic endogenous asthma. In normal subjects the 5-HT-uptake by platelets strictly obeyed Michaelis-Menten's kinetics. In patients with asymptomatic exogenous asthma, the active 5-HT-transport was moderately distorted in PRP and severely altered in PRP/PPP. Patients with symptomatic endogenous asthma exhibited already in PRP a dramatic transport disturbance. The alteration of the active 5-HT-transport was characterized by increasing uptake inhibition by rising 5-HT concentrations in plasma. This phenomenon could be due to changes in the platelet environment, defects in the platelet membrane or intrinsic platelet disorders. It is concluded that asthmatics have genetically or later acquired platelet disorder, which is more clearly observed in patients with symptomatic endogenous asthma than in those with asymptomatic exogenous asthma.

Adolescent↗
PubMed1982

The prophylactic effect of dipyridamole on the size of myocardial infarction following coronary artery occlusion.

Experimental myocardial infarction was induced in adult female Sprague-Dawley rats by ligation of the left coronary artery. During four weeks preceding the operation the animals were given dipyridamole (3 mg/kg initial body weight) i.p. twice a day 5 days per week. Control animals were given saline. Ten days after the operation the rats were killed and the hearts serially sectioned and stained. The volumes of necrotic and non-necrotic myocardial tissue were determined by morphometry on the histological sections. In the dipyridamole-treated animals the volume of non-necrotic myocardium was larger and the necrotic tissue volume smaller than in the control animals.

Animals↗
PubMed1981

Dipyridamole suppresses uptake of thymidine in human and bovine cells in vitro.

Dipyridamole has been shown to induce proliferative activity in heart muscle capillary wall cells in the rat. To test whether this effect is due to direct cellular stimulation we tested the substance in various in vitro systems (human lymphocytes, glial cells and endothelial cells; and bovine endothelial cells). During these conditions dipyridamole did not influence cellular proliferation. In all cell systems tested, uptake of labelled thymidine showed an inhibition by dipyridamole. This confirms the earlier finding that dipyridamole inhibits nucleoside uptake, and extends the finding to human cells.

Animals↗
PubMed1981

The effect of increased cardiac pressure load and volume load on the size of myocardial infarction following coronary artery occlusion.

The size of the myocardial infarction following standardized coronary artery occlusion was studied in rats with myocardial hypertrophy due to increased pressure load (aortic stenosis) and increased volume load (swimming exercise). The infarction was significantly smaller in the latter than in the former group. In normal control rats the infarction was larger than in the swimming-exercised rats and smaller than in the rats with aortic stenosis, but these differences were not statistically significant. The observations support the idea that the myocardial capillary neoformation previously shown to be induced by physical exercise may limit the infarction following coronary artery occlusion, whereas the absence of such a capillary reaction in pressure-induced cardiac hypertrophy renders the myocardium more vulnerable, to damage by a coronary occlusion. The size and distribution of the infarction was highly variable as was the configuration of the infarction in the individual heart. For an accurate determination of the size of the infarction, serial sectioning of the whole heart is necessary, with a distance between the sections examined not exceeding 0.5 mm.

Animals↗
PubMed1981

Capillary increase in the skeletal muscle of trained young and adult rats.

1. Capillaries in skeletal muscle were studied before and after physical training by prolonged swimming, in young and adult rats. 2. The mean area of striated muscle fibres was unchanged in both young and adult rats after training. 3. Training increased the capillary vasculature of skeletal muscle in both young and adult rats, but proportionally less in the adults.

Age Factors↗
PubMed1980

Capillary neoformation in skeletal muscle of dipyridamole-treated rats.

Rats were given 0.3 mg dipyridamole i.p. twice a day, 5 days/week for 3 weeks. Morphometric determinations of the hindlimb skeletal muscle of these animals showed that they had a higher degree of capillary vascular supply than the muscles of sham-injected control rats. The number of capillaries per muscle fiber was increased by 24%, the number of capillaries/mm2 by 22% and the number of capillaries in contact with each muscle fiber by 22%.

Animals↗
PubMed1979

The proliferative activity of myocardial capillary wall cells in variously aged swimming-exercised rats.

Cellular proliferation was studied by incorporation of 3H-thymidine in the hearts of young, adult and old swimming-exercised rats. The proliferative activity was measured by scintillation counting. The swimming exercise induced a significant proliferation of capillary wall cells in the younger age groups, suggesting a neoformation of myocardial capillaries in these rats, whereas no cell proliferation was recorded in the old rats.

Age Factors↗
PubMed1979

Effect of dipyridamole on the survival of experimental critical skin flaps.

The effect of dipyridamole (Persantin) on the survival of experimental skin flaps was studied. In controls 39% of the skin flap area survived. Intraperitoneal injection of dipyridamole 4 mg/kg twice daily starting four hours preoperatively increased the surviving area with 18%. This increase is statistically significant (p less than 0.05). The improved survival could be due to the vasodilatory action of the drug and/or proliferation of small bloodvessels induced by the drug.

Animals↗
PubMed1978

Proliferative activity of myocardial capillary wall cells in dipyridamole--treated rats.

The hearts of rats treated with dipyridamole were studied by light microscope autoradiography and measurement of tissue radioactivity after intravenous injection of 3H-thymidine. Total tissue radioactivity was significantly increased in the hearts of the dipyridamole-treated animals. Only capillary wall cells were labelled in the autoradiograms. The observations indicate a proliferation of capillary wall cells, suggesting a neoformation of myocardial capillaries during dipyridamole treatment.

Animals↗
PubMed1978

The myocardial capillary vasculature in repeated physical exercise. An experimental investigation in the rat.

The neoformation of myocardial blood capillaries was investigated on cardiac autoradiograms from 3H-thymidine injected rats that had been swimming-exercised for two weeks, rats that had been resting for three months following the exercise, and rats in which the rest had been followed by a second two-weeks period of exercise. The initial period of exercise induced a signficant capillary neoformation in the hearts. The newly-formed vasculature was found of functional significance still at the end of the resting period and available for the increased demands on the myocardial vasculature when the exercise was resumed.

Animals↗
PubMed1978

The reaction of the vascular pattern of the hypertrophied myocardium to increased cardiac volume load. A microangiographical study.

Myocardial stereo-microangiography was performed on 30 rats after swimming exercise for one or two periods with and without a previous operation for production of aortic stenosis. In 8 rats with aortic stenosis no swimming exercise followed, and 10 more rats served as normal controls. Swimming exercise resulted in a higher degree of cardiac hypertrophy than aortic stenosis. Both types of cardiac hypertrophy resulted in vascular adaptive reactions in the myocardium. The adaptive reaction to swimming exercise was found to be persistent, at least to some extent, and to be of use if the exercise was resumed. The adaptive alterations in aortic stenosis were further modified by a superimposed period of exercise, although the nutritive capillary vasculature only showed a slight and focal increase in density.

Animals↗