Comparative biochemistry and physiology. Comparative physiology.
Discontinued
Publisher:
Pergamon Press,. Oxford : Pergamon Press
Frequency: Monthly
Country: England
Language: English
Start Year:1992 - 1994
Identifiers
| ISSN: | |
| NLM ID: | 9441449 |
| (DNLM): | SR0082432(s) |
| (OCoLC): | 30378350 |
| LCCN: | sn 94043276 |
| Classification: | W1 CO435A |
Comparative aspects of Na(+)-K+ and Ca(2+)-Mg2+ ATPase in erythrocyte membranes of various mammals. This work is a comparative study of Na(+)-K+ and Ca(2+)-Mg2+ ATPase associated with the erythrocyte plasma membranes in different mammals. The method used to test the activity of these enzymes is based on quantitative measurements of ADP released during the reaction with HPLC: the chromatographic type is an Ion-Pair Reversed Phase. We have found that the levels of Ca2+ stimulated ATPase are higher than those of Na(+)-K+ ATPase in red blood cells of all the different mammalian species, with the only exception being lamb erythrocytes where the values of both the ATPase activities are almost equa...
Protein and nitrogen composition of equine (Equus caballus) milk during early lactation. Separation of whey protein from casein in equine milk was achieved by adjustment of pH to 4.3 without addition of calcium, and by ultracentrifugation at 189,000 g for 1 hr. True protein, whey protein, and casein decreased significantly during the first 28 days of lactation with the magnitude of decrease being greatest for whey protein. The proportion of nitrogen in whey protein:casein decreased from 85:15 to 54:46 during the 28 day time period. The concentration of non-protein nitrogen remained relatively constant at 500 mg nitrogen/l but increased in proportion from 2 to 13% of the total nitr...
Measurements of heart scores and heart weights in horses of two different morphic body types. Heart scores (the arithmetic mean of the QRS durations of the three bipolar limb leads for 10 cycles) and heart weights were determined from five draft type horses and five racing type horses, and evaluated for relationships between heart score and heart size within and between the two different types of horses. Horses were killed using a captive bolt gun, and actual heart weights were recorded using an electronic digital scale. The linear regression equation for heart weight versus heart score had a significant (P < 0.05) negative slope for racing types. The regression coefficients for heart ...
Skeletal muscle characteristics in 2 year-old race-trained thoroughbred horses. Skeletal muscle samples were obtained by needle biopsy from two depths of the m. gluteus medius of 50, young race-trained thoroughbred racehorses. Histochemical and biochemical characteristics of the muscle samples were analysed. Fibres were classified as type I, type IIa or type IIb on the basis of the pH dependent lability of the myosin ATPase reaction. The activities of citrate synthase (CS) and glycogen phosphorylase (Phos) were determined. Muscle fibre composition varied markedly between deep and superficial muscle samples and this was reflected in differences in the activities of citrate...
Comparative study of the oxyhaemoglobin dissociation curve of four mammals: man, dog, horse and cattle. 1. The entire oxygen dissociation curve (ODC) and the effects of temperature, pH and 2,3-diphosphoglycerate (DPG) on this curve, have been compared in four mammalians: man, dog, horse and cattle. 2. If the oxyphoric capacities are similar between these species (around 1.39 ml O2/gHb), their P50, measured in standard conditions, i.e. at pH 7.4; pCO2 40 mmHg and T 37 degrees C, varies between 23.8 (+/- 0.8) mmHg for the horse, 25.0 (+/- 1.4) mmHg for cattle, 26.6 (+/- 1.2) for man and 28.8 (+/- 2.6) mmHg for the dog. 3. The higher dispersion of the dog's P 50 is due to difference between breeds;...
Clearance of infused triglyceride by resting horses. 1. Clearance of infused lipid was observed in six mature resting horses, 2 to 6 hr after receiving a meal of alfalfa hay. 2. Intralipid, a 10% triglyceride emulsion, was infused at a rate of 0.2 ml/kg into the jugular vein. 3. Blood samples were obtained for 80 min post-infusion and assayed for plasma triglyceride concentration. 4. Clearance rate of the infused lipid was very slow (mean t1/2 = 269 min). 5. The clearance rate of the infused lipid in these horses was much slower than has been observed in other species. 6. The slow clearance of infused triglyceride in horses may suggest an inabil...
Effects of dehydration and rehydration on the intravascular space in horses. 1. The resistance of sub-tropical horses, and desert-dwelling horses to 72 hr dehydration/24 hr rehydration was investigated via changes in red cell parameters and plasma protein concentration. 2. Red cell count, haemoglobin and haematocrit increased up to 48 hr dehydration. Between 48 and 72 hr dehydration these parameters decreased, implying a fluid shift onto the intravascular space from the interstitium/hindgut. Most parameters had regained baseline values by 24 hr rehydration. 3. Mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration and total plasma protein were not...