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Biomedical subjects

R Flos

Publications and source records attributed to R Flos.

At least 19 recordsLinked to original sources
PubMed1992

Determination of textile dyes in organs of Oncorhynchus mykiss W. after in vitro exposure.

The quantitative determination in organs of Oncorhynchus mykiss W. of a premetallized dye (C.I. Acid Violet 66) and the azoic base (C.I. Acid Red 217), used in wool dyeing, is studied in this paper. UV-VIS Spectrophotometry was used for the chromatic quantification and atomic absorption spectrophotometry for the detection of the metal. The method described here is as satisfactory for the detection of some commercial dyes as the methods developed by ETAD (Ecological and Toxicological Association of the Dyestuffs Manufacturing Industry).

Animals↗
PubMed1991

Cadmium induction of metallothioneins in several dogfish organs.

Dogfish Scyliorhinus canicula were exposed to 50 mg/l Cd for 4 days for inducing metallothionein synthesis. Spleen, pancreas, kidney and gonads were dissected out and metallothionein presence was checked by means of gel filtration chromatography in Sephadex G-75 and sodium dodecyl sulphate polyacrylamide electrophoresis. In pancreas and kidney, a cadmium-binding protein with spectroscopical and electrophoretic properties similar to those of dogfish liver metallothionein was found. In the other organs, the existence of an analogue protein but at very low concentrations is feasible.

Animals↗
PubMed1987

Effects on dogfish haematology and liver composition after acute copper exposure.

1. Dogfish Scyliorhinus canicula was subjected to experimental acute copper pollution. At the lowest concentration no changes were recorded on haemoglobin levels whilst decreases of the erythrocyte number and haematocrit was found. 2. At higher concentrations near to the lethal doses, a general reduction of all blood parameters was observed. 3. Liver composition (protein, glycogen and lipid levels) was not affected by any copper concentration, over the duration of the experiments. 4. Results are discussed in relation to physiological responses of fish, acute concentration and metal action.

Animals↗
PubMed1987

Acute toxicity of copper to mediterranean dogfish.

Acute copper toxicity to dogfish (Scyliorhinus canicula) was determined. Median lethal concentrations (LC50) for 24 and 48 hr were respectively 16 and 4 mg/l. These results are compared with those for zinc in dogfish and with the values for copper toxicity in several teleosts obtained by other authors.

Animals↗
PubMed1986

Restraint stress induced changes in rat liver and serum metallothionein and in Zn metabolism.

24 h of a psychogenic stress (restraint) caused a strong increase of liver metallothionein (MT) levels. 3 h of stress were sufficient to induce an increase in liver MT, measured 21 h later, but the increase was much lower than in continuously restrained rats. Stress induction of liver MT was not due to food deprivation, since rats deprived for 24 h showed lower MT levels than stressed ones. Zn on MT presented the same qualitative but not quantitative pattern of response as MT protein. Liver cytosolic Zn was increased by restraint in spite of their being no decrease in serum Zn. Any treatment altered serum MT. Liver and serum MT were not correlated. The present results demonstrate that basically psychogenic stresses increased liver but not serum MT levels. No positive evidence for a relationship between corticosterone secretion and MT induction was found.

Animals↗
PubMed1986

The influence of restraint stress in rats on metallothionein production and corticosterone and glucagon secretion.

Earlier studies on metallothionein (MT) induction by stress used a wide range of stimuli, all of them considered as physical stressors. The present paper reports the effect of a basically psychogenic stress such as restraint on serum and liver MT. Male adult rats were stressed for 1, 12, 24 and 48 hours and then killed. Liver MT increased continuously throughout the experimental period. Rats deprived of water and food for 24 and 48 hours showed higher liver MT levels than control but lower levels than stressed ones. Serum MT was not modified by either restraint or water and food deprivation. The lack of relationship between the two MT pools was corroborated by the absence of a significant correlation between them. Restraint stress increased serum corticosterone but not glucagon levels, suggesting that only glucocorticoids are important in MT induction by stress. However, a strong circadian rhythmicity was observed in serum corticosterone but not in serum or liver MT in non-stressed rats. In addition, preliminary data with adrenalectomized rats indicate that glucocorticoids seem not to be essential in MT induction by stress. Likewise glucagon does not appears to be associated with MT induction by stress since its levels were not modified by restraint.

Adrenalectomy↗
PubMed1986

Effects of confinement stress and additional zinc treatment on some blood parameters in the dogfish Scyliorhinus canicula.

Several blood parameters were studied in the dogfish Scyliorhinus canicula subjected to different confinement conditions (transport and maintenance) and zinc contamination. Confinement stress significantly decreased erythrocyte counts (RBCC), haematocrit (Ht), haemoglobin (Hb), leucocrit (Lt), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Mean corpuscular volume (MCV) did not change with this stress and plasma glucose concentration significantly increased. In fish subjected to confinement stress conditions, Zn treatment significantly decreased Hb, MCH and MCHC and plasma glucose concentration. Ht and MCV did not change and Lt and RBCC significantly increased. Results are discussed related to other stress effects and effects of zinc treatment on fish confined in non-stressful conditions.

Animals↗
PubMed1986

Metallothionein in the liver of the small lizard Podarcis muralis.

A cysteine-rich protein presenting optical and biochemical features typical of metallothionein and a similar amino acid composition was found in the liver of the small lizard Podarcis muralis. Animals were given either CdCl2 (0.8 mg Cd2+/kg body wt) or saline (NaCl 0.9%) by i.p. injection for 3 days. A second group of animals were injected with a single dose of [35S]cysteine plus CdCl2 or saline. Lizard MT contained Zn and Cu when injected with saline and also Cd when injected with CdCl2. Metallothionein induction by cadmium was demonstrated by radioactive labelling.

Amino Acids↗
PubMed1986

Dogfish metallothionein--I. Purification and characterization and comparison with rat metallothionein.

A low-molecular weight metal-binding protein has been found in the liver of the dogfish (Scyliorhinus canicula) in both control and cadmium-treated animals and in both male and female animals. This protein is present as Zn, Cu-protein in control and as Cd, Zn, Cu-protein cadmium-treated (both water and i.p. administration) animals. This hepatic protein was characterized as metallothionein from several properties related to mammalian metallothionein. A different response to cadmium administration between sexes is suggested.

Amino Acids↗
PubMed1986

Dogfish metallothionein--II. Electrophoretic studies and comparison with rat metallothionein.

A low-molecular weight metal-binding protein has been isolated and characterized as metallothionein in the liver of the dogfish (Scyliorhinus canicula). This protein is present in both male and female animals and both control and cadmium-treated (both water and i.p. administration) animals as revealed by SDS-PAGE studies. Dogfish metallothionein shows the same metal-dependent anomalous behaviour as rat metallothionein in SDS-PAGE. SDS-PAGE is a good method to identify a protein as metallothionein.

Animals↗
PubMed1985

Cd-, Zn-, Cu-binding protein in the elasmobranch Scyliorhinus canicula.

A Cd-, Zn-, Cu-binding protein was isolated from the liver of dogfish subjected to environmental experimental contamination (50 ppm Cd). It was also found in liver from untreated fish. This protein has a high absorption at 250 nm and a low absorption at 280 nm, suggesting a mercaptide bond and a lack of aromatic amino acids. The SDS-PAGE pattern and changes in absorption spectrum on adding Cd or lowering pH are found as for mouse MT. The protein contains Cu and Zn in control and Cu, Zn and Cd in treated fish. Cd levels in the protein are significantly higher in females and significantly increase with treatment duration. Copper levels decrease after 96 hr in males and 6 days in females.

Animals↗
PubMed1984

Dogfish liver and kidney tissue respiration after zinc treatment.

Tissue oxygen consumption in liver and kidney of dogfish Scyliorhinus canicula L. were measured by manometric techniques after two types of zinc treatment: in vitro (1, 15, 60 and 180 ppm) and in vivo (subacute 10 ppm/21 days, and acute 80 ppm/24 hr). All in vitro treatments exert a strong inhibitory effect in both tissues. In vivo treatment affects liver tissue respiration at the acute dose. Subacute treatment shows no effects in both tissues. Results are discussed related to previous data on gill tissue respiration and zinc tissue accumulation in the dogfish.

Animals↗
PubMed1984

Metabolic levels in dogfish gill tissue after zinc treatments.

Dogfish were subjected to acute (80 ppm/24 hours) and subacute (10 ppm/21 days) zinc treatments before measuring the ATP, glycogen, protein, and lactate levels. Acute treatment varies significantly the levels of all the metabolites tested while only protein content is significantly lower after subacute treatment. The results are discussed in relation to the hypoxia effect produced by the metal and the related responses of the fish.

Adenosine Triphosphate↗
PubMed1982

Oxygen uptake by dogfish gill tissue after several in vitro zinc treatments.

Oxygen consumption by dogfish gill tissue is measured after several in vitro zinc treatments ranging from low contamination (0.2 ppm) to the 50% lethal concentration at 24 hours (180 ppm). Zinc inhibits respiration from 15 ppm and the inhibition increases along with greater zinc concentrations from 15 to 60 ppm. Thereafter the respiration level becomes stabilized with no further inhibition increases. A similar pattern is described with homogenates but inhibition is stronger and faster, while respiration does not stabilize. The results are discussed in relation to the possible role of the membrane and the toxicological effects caused by zinc.

Animals↗