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Biomedical subjects

M Wachtlová

Publications and source records attributed to M Wachtlová.

At least 19 recordsLinked to original sources
PubMed1985

Thyroxine-induced cardiomegaly in rats of different age.

In the present study the effect of thyroxine treatment on the development of cardiomegaly was compared in young (10-day-old) and adult (12-week-old) rats. L-thyroxine was administered subcutaneously in a dose of 1 mg per kg b.w. for 5 days. In young thyroxine-treated rats the heart weight increased by 79% in comparison with the control rats. The number of blood capillaries and muscle fibres per mm2 remained unchanged. The concentration of hydroxyproline was even lower than in control animals. The number of 3H-thymidine-labelled muscle cell nuclei was significantly higher both in the left and right ventricles of thyroxine treated rats. The density of capillaries and muscle fibres was significantly lower in adult rats than in the group of young animals. In adult thyroxine-treated animals the heart weight was higher by 36%, the number of capillaries and muscle fibres as well as the concentration of hydroxyproline was unchanged. Thyroxine induced significant increase in the number of DNA synthesizing nuclei of muscle cells in the left ventricle while the change in the right ventricular myocardium was not statistically significant. The present data indicate that a hyperplastic response of cardiac muscle cells to thyroxine occurs in both ventricles of young rats and also in the left ventricle of adult animals.

Aging↗
PubMed1977

DNA synthesis in the ventricular myocardium of young rats exposed to intermittent high altitude (IHA) hypoxia. An autoradiographic study.

Intermittent high altitude (IHA) hypoxia (7000 m) increased the wet weight of the right ventricular myocardium of 30-day-old rats after two 4 h/day exposures. During the same period the number of DNA-synthesizing nuclei of both muscle and non-muscle cell types increased proportionally. After 4 such exposures to hypoxia the number of 3H-thymidine-labelled nuclei in both cell types increased further. In addition, the number of labelled nuclei increased significantly in the yet un-enlarged left ventricle. While there was no difference in the number of DNA-synthesizing cells between the right and left ventricles in control animals, a significant increase in the number of cells involved in DNA synthesis in the right ventricle was found in both groups of animals exposed to IHA hypoxia. These results show that DNA synthesis in myonuclei of the ventricular myocardium can be stimulated in 30-day-old rats, i.e. at the very end of the weaning period.

Altitude↗
PubMed1975

Carrageenin-induced experimental pneumonia in rats.

The authors verified the possibility of modelling pneumonia by the intratracheal administration of carrageenin solution into the lungs of rats. The most satisfactory dose was found to be 0.5 ml 0.7% carrageenin solution administered at 40 degrees C. The disease, evaluated by the morphological and functional signs, culminated after two days. Both macroscopically and histologically the lungs displayed typical signs of catarrhal suppurative aspiration bronchopneumonia. Functionally, marked tachypnoea (mean 180 cycles/min as against 110 c/min in the conscious controls) and raised functional residual capacity were found. A drop in the respiration rate and in FRC after bilateral cervical vagotomy indicated that a reflex component participates in the origin of the above two signs.

Airway Resistance↗