PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Skate”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1978

Urea levels in plasma and erythrocytes of the southern fiddler skate, Trygonorhina fasciata guanerius.

Plasma and erythrocyte samples from Trygonorhina fasciata guanerius were analysed for urea content. The erythrocyte urea concentration is higher than plasma urea concentration. The difference in concentration is probably due to the presence of urea normally bound to protein within the erythrocyte. Erythrocyte urea concentrations followed environmentally induced changes in plasma urea concentrations. Naturally occurring plasma urea concentrations, exceeding 500 mMolar, are some of the highest recorded for an elasmobranch.

Animals↗
PubMed1977

The Salop Skate.

Explore the source record for details and available documents.

Adolescent↗
PubMedDate not supplied

[Magnesium-activated adenosine triphosphate of the ampullae of Lorenzini of the skate Dasyatis pastinaca].

Studies have been made on Mg2+-activated ATPase of electroreceptor structures of the lateral line organin the ray D. pastinaca. It was shown that the enzyme is activated by magnesium ions (2.5 mM), maximum activation being observed at pH 8.0-8.5. The enzyme exhibits substrate specificity to adenyl nucleotides. Walls of ampullar canals also contain Mg2+-ATPase, however the level of the enzymatic activity in these walls is significantly lower.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Effect of ergotoxin on gastric motility in the skate, frog and turtle].

DG-erotoxine (SPOFA)--200 mg/kh b. w. has no effect to the motor activity in scates. The dose of 500 mkg/kh produces 20-30 min. after injection the excitation of contraction followed by the inhibition. In frogs the dose of 25 mkg/kg produces the excitation of stomach contractions. The dose of 100 mkg/kg initially stimulates motor activity, later on--inhibits it. In the tortoise the dose of 25 mkg/kg increases the contraction of the stomach the dose of 2000 mkg/kg inhibits it.

Animals↗
PubMedDate not supplied

[Perception of chemical and temperature stimuli by the ampullae of Lorenzini in in skates].

Recording impulse activity in single nervous fibers, studies have been made on the effect of chemical and thermal stimuli on the activity of Lorenzini ampullae in the rays Dasyatis pastinaca and Raja clavata. Application of the diluted sea water to the opening of ampullary canal increases the discharge rate of the receptors resulting into subsequent adaptation, whereas the increase in water salinity causes opposite changes. Threshold changes in the salinity of sea water amount 1--2%. Thermal transient in the sea water at the vicinity of the opening of ampullary canal did not affect the activity of the receptors. A decrease in temperature at the vicinity of receptor cells resulted in a transient rise of the firing rate of the receptors, while the increase of temperature decreased the activity of the receptors.

Adaptation, Physiological↗
PubMedDate not supplied

Amino acids and cell regulation.

Free amino play an important role in regulating cell volume in fishes. Four tissues/cells (skeletal muscle, RBC, brain, and myocardium) of the little skate, Raja erinacea, were selected for detailed study because of their special importance or unique advantage as experimental models. Three particular amino acids, beta-alanine, taurine, and sarcosine play a predominant role in all four tissues. As in higher vertebrates, amino acid uptake in skate brain, heart, and RBC is mediated via a Na+-dependent process. Amino acids leave the skate brain rapidly in response to a sudden decrease in plasma osmolality and/or to a simultaneous drop in extracellular Na+ concentration. However, although amino acids are important for volume regulation in normal brain cells, they do not appear to be likely candidates for the unidentified "idiogenic" osmolytes in mammalian brain cells. The high concentration of taurine in skate myocardium is of special interest because of the special role of this amino acid in myocardial contractility. Thus, unlike beta-alanine and sarcosine, taurine may play a dual role in regulating both cell volume and contractility of myocardial cells. The isolated skate atrium is well suited for in vitro studies of these two processes.

Amino Acids↗
PubMed1979

A longitudinal study of ice hockey in boys aged 8--12.

A group of fifteen boys (experimental or competitive) were studied over a five year period of competitive ice hockey beginning at age 8. The subjects were members of a team which averaged 66 games per year, ranging from 50 at age 8 to 78 at age 12. In addition, they practiced twice a week with heavy stress on skating and individual puck handling skills. A second group of eleven boys (control or less competitive) were studied from age 10 to 12. The latter subjects played an average of 25 games per year and practiced once a week. All subjects were measured each year on skating and puck control skills, fitness-performance tests, grip strength, physical work capacity as well as height and weight. The results demonstrate learning curves for skating and puck control tests which, while typical in nature, show extremely high levels of achievement. Fitness-Performance, grip strength and physical work capacity levels of the competitive group are extremely high in comparison with data from other countries.

Body Height↗