Biomedical subjects

M Gabrovska

Publications and source records attributed to M Gabrovska.

4 recordsLinked to original sources

PubMed1984

[Tubular structural pattern of filaments of elastic fibers].

Substructural organization and morphogenesis of elastic fiber filaments (EFF) from different organs (blood vessels, auricular cartilage, skin) are described. EFF reveal a tubular pattern of organization. In cross section, the filament's "wall" is build up of 4 dense particles (subunits), which surround an electron-lucent interior; in longitudinal section, subunits seems to be arranged in a chain-like manner. The EFF's tubular organization is somehow similar to that of intermediate filaments and cytoplasmic microtubules. An universal structural pattern for both, intra- and extracellular filamentous structures, with skeletal function is suggested.

Animals↗

PubMed1982

Secretory features of chondrocytes related to morphogenesis of the elastic elements in the auricular cartilage.

The well-developed secreting vacuolar system is a characteristic feature of all chondrocytes (CH) during prenatal and early postnatal ontogenesis as well as of the CH near the perichondrium in the adult rat's auricular cartilage. Two kinds of secretion vacuoles exist, dense vacuole (DV) and electron lucent vacuoles (LV). The DV are heterogeneous in size, matrix appearance and origin. The factors (organ necessities and chemical maturation) responsible for the DV matrix heterogeneity are discussed. The presence of dilated rough endoplasmic cisternae with local parts of their cisternal surfaces without bound ribosomes suggest the existence of a direct secretory pathway which bypasses the Golgi complex. During prenatal ontogenesis the extracellular matrix of the auricular cartilage consists of bundles of elastic microfibrils and primary elastic fibres. The elastic microfibrils are tubular structures with a wall composed of 3-5 subunits. After birth the primary elastic fibres are joined to form intercellular septae. The presence of matrix vesicles is discussed with regard to the fine differentiation of the auricular elastic system by their lysosomal activity.

Animals↗

PubMed1981

[Matrix vesicles in various "elastic" organs].

Matrix vesicles (MV) have been found during normal development in the rabbit and rat aorta and pulmonary trunk as well as in the elastic cartilage of the rat external ear. In spite of the morphological variability of MV, two basic types can be ruled out: MV with dense osmiophilic content, and light or electron-translucent MV. MV of the first type are considered to be extracellular lysosomes. MV in the vessel wall are predominantly localized in the subendothelium, and the border-zones between media and endothelium or media and adventitia; in elastic cartilage they are localized near the perichondrium. Especially often they can be seen at the place of contact between elastic and other fibers of the intercellular space. They can even penetrate the elastic membranes and plates. The parts of the organs mentioned encounter higher functional demands and are more active during development and growth. The MV appear almost exclusively a short time before birth, and predominantly during the first 20-60 days of postnatal life. Their origin may be due to exocytosis and the detachment of parts (Mikroapokrinie) of endothelial cells, smooth muscle cells, fibrocytes and chondrocytes. The MV are considered to be a substrate for subsidiary extracellular mechanisms of adaptation during the normal ontogenesis of the elastic tissue of these organs.

Animals↗

PubMed1979

[Ultrastructural manifestations of the secretory function of the chondrocytes in elastic cartilage].

The authors examined ultrastructural manifestations of the secretory function of chondrocyetes in the auricular tendon of rats. They found that chondrocyetes were active secretorily in the prenatal and early postnatal ontogenesis; in later age such activity possessed mainly those chondrocytes located subperichondricaly. The existance of direct communications of cysternas of the granulated endoplasmic reticulum with extracellular area was interpreted as a possibility for direct release of the secretory products. Small coated vesicules with dense content were followed-up from the Goldi's organs till their openings on the cellular surface. Two types of vacuoles were differentiated-some with optically dense content, localized in the Goldi's organs, and others-optically empty, which were encountered in their boundaries as well. A concept was given that the first type originates from the granulated endoplasmic reticulum and transported protein product, but the second type-from the Goldgi's complex and transported probably polysaccharides.

Animals↗