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O Mrázková

Publications and source records attributed to O Mrázková.

15 recordsLinked to original sources
PubMed1992

[The effect of verapamil and nifedipine on the development of experimental atherosclerosis in rabbits].

The main objective of the study was to investigate the effect of the calcium antagonists Verapamil (2 mg.kg-1.day) and Nifedipine (1 mg.kg-1.day-1) on cholesterol (1%) induced atherosclerosis in rabbits. The drugs were administered s.c. twice daily over a period of 8 weeks. Blood lipid levels were determined three times during the experiment. After the experimental period the animals were killed and macroscopic changes on the aorta were recorded. For histochemical investigation samples were taken from the arch of the aorta and coronary artery. In cryostat sections lipids were determined by Sudan black B and Fett rot 7 B and the following enzymes were assayed: acid phosphatase, non-specific and acid esterase, acid beta-galactosidase, dipeptidyl peptidase I and II, and glucose-6-phosphate dehydrogenase. Following treatment with the calcium antagonists the levels of triacylglycerols and of total cholesterol were significantly increased in comparison with the control and diet groups. The ratio of HDL cholesterol to total cholesterol decreased in the treated animals. In lipoid plaques the activity of enzymes was enhanced in all experimental animals. There were however no qualitative differences in the composition of plaques between individual groups, which exhibited only quantitative differences. The number of migrating macrophages was increased only in the nifedipine treated animals. The extent of plaques was significantly decreased after nifedipine treatment, whereas verapamil failed to exert antiatherogenic effect. (Tab. 2, Fig. 4, Ref. 22.).

Animals↗
PubMed1986

Enzymatic heterogeneity of the capillary bed of rat skeletal muscles.

This study of the capillaries in rat skeletal muscle involved the use of a histochemical method that allows one to distinguish between arterial and venous portions of capillaries. Under controlled staining conditions, the arterial portion of the capillary bed reacts positively for alkaline phosphatase (AP) activity, and the venous portion is positive for dipeptidyl peptidase IV (DPP IV) activity. A short transitional capillary segment is positive for the activity of both enzymes. Capillaries of the normal soleus muscle and the red and white portions of the sternomastoid muscle have been quantitatively analyzed. Quantitative data demonstrated differences in capillary dimensions among the muscles studied. Capillaries of the white part of the sternomastoid were the longest, and they had the shortest DPP IV-positive segment (8% of the total capillary length). Capillaries of the soleus muscle were the shortest, and they also had short DPP IV-positive segments (16%). In contrast, the DPP IV-positive segments of the red part of the sternomastoid occupied 60% of the total capillary length. Survey cross sections reveal a mosaic distribution of patches of capillaries stained for AP and DPP IV activity. This study reveals that within given bundles of muscle fibers, the capillaries that run parallel to the muscle fibers are aligned relative to one another in such a manner that their arterial and venous segments are in register.

Animals↗
PubMed1986

Enzymatic differentiation of arterial and venous segments of the capillary bed during the development of free muscle grafts in the rat.

The revascularization of freely grafted muscles in the rat was studied by histochemical reactions that on frozen sections stain the arterial part of the capillary bed blue (alkaline phosphatase [AP] reaction) and the venous part of the capillary bed red (dipeptidyl peptidase IV [DPP IV] reaction). In 112 rats the extensor digitorum longus or soleus muscles were freely grafted and removed at various times up to 93 days following the surgery. In cross section, the capillaries of a normal muscle show a mosaic pattern of staining for the activity of the two enzymes. After grafting, DPP IV activity of capillaries is lost throughout the entire graft within a day or two; but within ischemic muscle, weak and diffuse AP staining persists in capillary remnants for up to 6 days. In the very periphery of the graft AP staining is also preserved in partially damaged capillaries. By 4 days, new AP-positive capillaries can be identified at the periphery of the graft, and in succeeding days AP-positive capillaries are found progressively nearer the center of the graft. At 7 days, the capillary/muscle-fiber ratios are 66% of normal in the periphery of the graft and 44% in the intermediate zone. DPP IV-stained capillaries are not seen until 7 days after grafting. By 60 days, when the grafts have become stabilized, the mosaic pattern of capillary staining has become reestablished. In mature grafts, the number of capillaries per unit area was slightly higher than that in control muscles, but the capillary/muscle-fiber ratio was slightly lower, owing to the smaller than normal cross-sectional areas of the regenerated muscle fibers.

Animals↗
PubMed1986

Blood vessel ontogeny in upper extremity of man as related to developing muscles.

Vascular bed and its relationship to differentiating muscular tissue was studied in a set of 104 upper limbs of human embryos and foetuses, gradually increasing from 10 to 120 mm C-R length. Knowledge obtained on the ontogeny of vascular bed was supplemented by findings in 75 limbs of adults treated by preparation technique. Embryonic and foetal material was treated histochemically a--to demonstrate vascular bed reaction for alkaline phosphatase (AP), ATPase, and dipeptidylpeptidase IV (DPP IV), b--to study differentiating muscular tissue for enzyme--ATPase and tetrazoliumreductase (NaDH2, c--to distinguish muscular tissue elements with toluidine blue staining for degree of maturity. Observations concerned several items, namely a--the ontogeny of main arterial trunks in the forearm and hand, b--muscle fibre type differentiation in antebrachial muscular primordia, c--formation of vascular bed as related to differentiating muscular tissue in the forearm and hand. Therefore our results are grouped as follows: ad a--Arterial trunks differentiate along with other limb structures in 12-18 mm C-R length embryos. Thus in embryos above 18 mm C-R length antebrachial and hand trunks are fully formed. Vascular trunks differentiate from deep vascular network via gradual reduction and magistralization in conformity with the general laws of haemodynamics. All arterial trunks forming in the limb during the ontogeny branch off the original axial artery in regio cubiti. In a. radialis trunk it has been ascertained that this blood vessel does not originate from a. brachialis superficialis, as generally reported, but its formation conforms to the same general principles as blood vessel trunks. So it branches off the original axial artery, as other trunks do. A. mediana formed during vascular trunks differentiation later in the ontogeny does not obliterate but changes into the constant a. comitans n. mediani. ad b--First involved in differentiation in antebrachial muscular primordia are the "fast" type fibres (according to Peter et al., 1972) (fast glycolytic-FG-type fibres followed by fast oxidative glycolytic-FOG-type fibres) in 27-30 mm C-R length embryos. "Slow" type fibres (slow oxidative-SO-type fibres) may not be demonstrated histochemically in antebrachial muscles earlier than 45 mm C-R length foetuses. The maturity of muscular elements may be demonstrated by staining with toluidine blue on cytoplasm basophilia of cells. Sarcolytic myotubes in muscular primordia histochemically display typical features which distinguish them markedly from other differentiating muscle fibres.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphatases↗