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Z F Savik

Publications and source records attributed to Z F Savik.

10 recordsLinked to original sources
PubMed1983

[Effect of prolonged hypokinesia on the growth and skeletal musculature in the rat].

Hypokinesia lasting for 1-5.5 months does not produce any muscular atrophy, but results in ceasing their growth and the growth of the animal. In the muscles, besides the soleus muscle, not any essential structural changes occur. The changes in the soleus muscle are manifested as a focal sclerosis and formation of new muscle fibers. They are considered as a result of a disturbed hemodynamics in it, that occurs during the first days of hypokinesia. During the readaptation period the animals and their muscles begin to grow again. A suggestion is expressed that one of the pathogenic causes making the growth stop is the stress that decreases the somatotrophic function of the hypophysis.

Adaptation, Physiological↗
PubMed1978

[Effect of temperature on the duration of mitosis in mammalian cells cultivated outside the body].

Nine cell strains of different origin were cultivated at 28--36 degrees with the interval of 2 degrees. During the phase of logarithmic culture growth, the duration of mitosis (Tm) was determined by means of colchicine method. A strict temperatural dependence Tm, obeyed to Arrenius' law was revealed. Temperature range within which Arreinius' law is valid in different cell strains is not alike. Cultivation of L cells and connective tissue cells from Chinese hamster to 39, 41and 42 degrees demonstrated their upper critical point Tm to be for L cells 39 degrees, for connective tissue cells from the Chinese hamster--41 degrees. Electron microscopic investigations demonstrated that cell cultivation within physiological (mitosis destroying) range of temperatures does not notably effect their ultrastructural organization.

Animals↗
PubMedDate not supplied

[Morphological study of the myocardium of monkeys after anti-orthostatic hypokinesia].

By histological, morphometric and gravimetric methods the hearts of 7 monkeys exposed to head-down tilt at -6 degrees were examined (2 monkeys were exposed to head-down tilt for 7 days and 5 monkeys were exposed to hypokinesia for 7 days and then to head-down tilt for 12 days; 4 additional monkeys were used as controls). During head-down tilt the heart weight increased due to blood pooling in the Thebesian vessels which was in turn associated with blood redistribution and accumulation in the vessels and parenchymal organs of the upper body. During 7- and 12-day head-down tilt myocardiocytes of the papillary muscles of the ventricles were not enlarged, and the number of functioning capillaries in the papillary muscles diminished.

Animals↗
PubMedDate not supplied

[Effect of 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 on growth and remodeling of rat bones during hypokinesia (histomorphometric study)].

The tubular bones of the fore- and hindlimbs of rats immobilized for 5 weeks were examined morphometrically and histologically. The rats were regularly given per os 1,25(OH)2D3, 24,25(OH)2D3 or their combination. The uptake of 24,25(OH)2D3 at a dose of 1.25 micrograms or a combination of 1,25(OH)2D3 and 24,25(OH)2D3 at a dose of 0.03 + 0.25 micrograms led to the recovery of the linear and volume-weight rates of bone formation that changed during hypokinesia. However, these D3 metabolites did not restore the width of the epiphyseal growth plate, whereas the size of the primary and secondary spongiosa returned to normal or exceeded it in response to 24,25(OH)2D3 at a dose of 1.25 micrograms and 1,25(OH)2D3 at a dose of 0.15 micrograms, respectively (only these two doses were used); in other words, the D3 metabolites prevented osteoporosis which is typical of hypokinesia. It is assumed that hypokinesia may produce either disorders in D3 metabolism or changes in the sensitivity of bone cells to active D3 metabolites and other hormones that are directly or indirectly involved in osteogenesis regulation.

24,25-Dihydroxyvitamin D 3↗
PubMedDate not supplied

[Effect of space flight factors on skeletal muscle ultrastructure].

By electron microscopy ultrastructures of myofibers of the soleus and gastrocnemius muscles of rats flown in zero-g and 1 g were examined. It was found that 4.5--9 hours postflight the soleus of weightless rats showed local destruction of the contractile and mitochondrial systems accompanied by metabolic changes in muscle fibers. Exposure to artificial gravity partially prevented changes in muscle fibers. Examinations of muscle fibers 25 days postflight demonstrated that the changes were reversible. No changes were seen in the mixed -- gastrocnemius -- muscle of both animal groups.

Animals↗
PubMedDate not supplied

[Ultrastructure of the blood vessels and muscle fibers in the skeletal muscle of rats flown on the Kosmos-605 and Kosmos-782 biosatellites].

Electron microscopy was used to study ultrastructures of the wall of blood vessels and muscle fibers of the red (soleus) and mixed (gastrocnemius) muscles of rats flown on Cosmos-605 for 22.5 days and on Cosmos-782 for 19,5 days and sacrificed 4-6 hours, 48 hours and 25-27 days postflight. It was demonstrated that the orbital flight did not induce significant changes in the ultrastructure of blood vessels of the soleus and gastrocnemius muscles but caused atrophy of muscle fibers and reduction of the number of functioning capillaries. Readaptation of the soleus vascular system to 1 g led to degradation of permeability of capillary and venular walls and development of edema of the perivascular connective tissue. This may be one of the factors responsible for dystrophic changes in muscle fibers.

Animals↗