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Biomedical subjects

V Nováková

Publications and source records attributed to V Nováková.

At least 19 recordsLinked to original sources
PubMed1979

Total RNA content and blood flow in rat brain after RNA administration.

The changes in blood flow through selected brain structures and the changes in the total RNA content of cells of these structures were examined after a single administration of yeast RNA to 6-month-old male rats. The total content of ribosomal RNA in cells of the limbic system (septum, hippocampus, hypothalamus) increased 48 hrs after the administration of 100 mg i.p. yeast RNA , dropped after 7 days (in hypothalamus), 21 and 30 days (in hippocampus), 30 days (in septum). In cells of the limbic system as a whole there is a higher total RNA content in experimental rats. No changes were observed in the cells of parietal brain cortex. Blood flow increased in limbic structures 21 and 30 days after RNA administration and in septum and in hippocampus also 90 days after application. No changes were observed in parietal brain cortex, bulbi olfactorii, cerebellum and brain stem. Histochemical changes correlated positively with blood flow changes in the limbic system 14, 21, 30 and 90 days after RNA application. The body weight of experimental rats did not differ from that of control animals. The changes in haemodynamic parameters were transient and were demonstrated as fluctuations in heart rate, cardiac output, and peripheral resistance. Blood pressure experienced no changes.

Animals↗
PubMed1978

Hypocholesterolemic effect of ascorbic acid in maturity-onset diabetes mellitus.

A significantly lower vitamin C concentration has been found in the blood and particularly in the leukocytes of hypercholesterolemic diabetic patients than of healthy blood donors. Ascorbic acid administered in a dose of 500 mg per day for 12 months to metabolically stabilized hypercholesterolemic subjects with maturity-onset diabetes mellitus (diabetic diet without insulin or diabetic drugs) brought about a striking decline of cholesterolemia and a moderate decline of triglyceridemia. The serum lipid level in the control group given placebo remained unaltered. A daily administration of 500 mg of ascorbic acid for six months failed to affect the fasting level of serum immunoreactive insulin. It is assumed that the long-term administration of ascorbic acid to maturity-onset diabetics removed the tissue ascorbate deficiency and improved the liver ability to compensate the increased endogenous synthesis of cholesterol by its enhanced transformation to bile acids.

Ascorbic Acid↗
PubMed1977

Significance of the weaning period for natality and maternal behaviour of laboratory rats.

Normally weaned females (at 30 days) displayed seasonal cyclic changes in natality and the characteristics of the young. Natality in the spring and summer was high, the litters were large, the proportion of females and males in the litter was equal and deaths among the unweaned young were very few. Natality in the autumn and winter was low and the litters were small and consisted mainly of males. The death rate among the young was higher than in the spring and summer. Prematurely weaned females (at 15 days) displayed no seasonal cycle either in natality or in the characteristics of the young. The studied parameters corresponded to the values found in the spring and summer in normally weaned females. No differences were found in maternal retrieving, but there was a marked difference in nest-building. The normally weaned female tore up paper (building material) into small fragments 24 hours before giving birth and dropped the young into a soft nest of finely shredded paper. On leaving the nest it covered the young up. The prematurely weaned female scattered the paper about the cage 24 hours before giving birth and dropped the young into a depression stamped out among whole pieces of paper. It did not cover the young up on leaving the nest. The cause of the difference in building behaviour is evidently that prematurely weaned females failed to acquire early experience of this behaviour between the 15th and 30th day of life.

Animals↗
PubMed1976

A perfluorochemical oxygen carrier (fluosol-43) in a synthetic medium used for perfusion of isolated rat liver.

An emulsion of perfluorotributylamine (Fluosol-43) was used as substitute for the gas-carrying function of erythrocytes in a synthetic medium for perfusion of isolated rat liver. The efficiency and effect of this synthetic gas-carrier were evaluated from measurements of the concentrations of rat albumin, the unsaturated vitamin B12-binding capacity of small-molecular-size vitamin B12-binding proteins (UBBC of SBP), urea nitrogen, glucose, sodium, potassium, alanine amino transferase (ALAT) in the medium, and the incorporation of 14C-lysine into the circulating proteins. Secretion of bile, portal pressure, PO2, PCO2 and pH in the affluent and the effluent mediums were also measured. The results demonstrate that the oxygen-carrying capacity of the medium and the metabolic functions of the liver were higher, and the liver damage less, when the medium included Fluosol-43 than without it. The albumin synthesis and the secretion of bile were as high as has been reported for perfusions with erythrocytes. This indicates that the oxygen carried by the Fluosol-43 was utilised by the liver, and that the metabolic functions were not adversely affected during 4 h of perfusion by the medium containing Fluosol-43.

Alanine Transaminase↗
PubMed1976

The evaluation of synthetic oxygen carriers by perfusion of isolated rat liver.

The perfluorochemical FC-80 emulsion was added as oxygen carrier to a synthetic medium used for perfusion of isolated rat liver. The oxygen carrying function of FC-80 was evaluated from measurements of serum albumin synthesis and incorporation of 14C-lysine into the proteins in the medium. The effect of changes in flow rate of the medium on the evaluation of FC-80 was investigated. The results show that there is a correlation between the serum protein synthesis and the oxygen supply only when the liver is hypoxic. In hypoxic liver both the addition of FC-80 and the increase of the flow rate improve the oxygen supply which is indicated by increased serum protein synthesis. The effect of FC-80 on serum protein synthesis is different at different flow rates. For the evaluation of the oxygen carrying function of FC emulsions from the metabolic function of the liver such a flow rate and affluent PO2 are optimal in which the FC is a limiting factor for sufficient oxygen supply.

Animals↗
PubMed1976

Effect of hyper- and hypothyroidism on the alpha-tocopherol concentration in serum and some organs of growing rats.

The finding of a raised alpha-tocopherol concentration in the heart muscle, liver, skeletal muscle and serum during experimental hyperthyroidism, lasting 30 days, made the authors assume that this cumulation is a transient phenomenon which would disappear during a prolonged metabolic disorder as a result of energetic breakdown of the organism. The purpose of the paper was to verify this view. The investigation with experimental hyper- and hypothyroidism was made in 120 rats with a mean weight of 160 g. To 60 animals daily 100 mug thyroxin were administered by the i.p. route, 48 animals were given 2.5 Carbimazol daily by mouth to induce hypothyroidism and 12 animals served as controls. The animals were fed the same diet. The effect of the administered preparations was examined after 20, 30, 40, 50 and 60 days. In hypothyroid animals the 50th day was omitted. The results revealed: 1. In hyperthyroid animals the body weight was almost constant to the end of the experiment. However these animals had a significantly raised weight of the heart muscle and liver, as compared with the remaining two groups. 2. In hyperthyroid animals the highest alpha-tocopherol concentration in the heart muscle and skeletal muscle was recorded after 20 days. During subsequent time intervals the alpha-tocopherol concentration in the heart muscle declined gradually. In the skeletal muscle a dramatic decline occurred after 40 days and proceeded to the end of the investigation when the recorded values were at the borderline of detectability. This finding confirmed the authors view that the alpha-tocopherol cumulation in muscle exposed to an increased work load is a transient phenomenon and disappears during prolonged hyperthyroidism before the breakdown of the organism. 3. In hyperthyroidism no correlation was found between the alpha-tocopherol concentration and the lipid content of organs and skeletal muscle. This correlation was found in hypothyroidism. 4. The alpha-tocopherol serum level in hyperthyroidism was significantly higher than in hypothyroidism. 5. In hyperthyroidism the alpha-tocopherol cumulation in liver increased gradually, and reached its maximum after 50 days. At a time when the alpha-tocopherol concentration in the heart muscle and skeletal muscle declined already, its liver concentration increased. This phenomenon may be associated with the increasing protein synthesis in the liver during hyperthyroidism, or with other phenomena which call for further investigation.

Animals↗