Validation of Creatine, Glycogen and L-(+)-Lactate Determination in Biopsy Samples of Bovine Musculus Diaphragma

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (1995), 42(1), 13-26

Whereas reliable measurements of diaphragmatic force and electrical activity are now available in calves, evidence that substrate contents in the bovine diaphragm can be accurately measured is still ... [more ▼]

Whereas reliable measurements of diaphragmatic force and electrical activity are now available in calves, evidence that substrate contents in the bovine diaphragm can be accurately measured is still lacking. The purposes of the present study were therefore a) to describe and test the reliability of methods and procedures used for sampling, lyophilisation, extraction and dosage of muscular lactate, glycogen and creatine contents and b) to report the variation in their levels found along the bovine diaphragm and among individuals. The repeatability of the results yielded by a) assaying the extracts, b) processing and assaying the extracts and c) taking samples at different sites in the muscle was assessed. Neither assay, nor processing effects were significant (P < or = 0.05). Substrates were found to be homogeneously distributed within the two muscles studied. Substrate contents expressed per unit of muscle weight or total creatine were neither more or less variable than when expressed per unit of dry matter. [less ▲]

Three cases of Pemphigus Foliaceus in horses

in Proceedings of the XXVth Congress of the World Veterinary Association (1995)

Optimization of 3-methylindole provocation test in calves, with special regard to appropriate dosage regimen for safe and reversible pulmonary changes

in Pflügers Archiv : European Journal of Physiology (1995), 430

Comparative assessment of right ventricular performance from the pressure-volume relationship in double-muscled and conventional calves.

in Canadian Journal of Veterinary Research = Revue Canadienne de Recherche Vétérinaire (1995), 59(2), 135-141

Forty-one and 55 records of right-sided and systemic arterial pressures, cardiac output, and end-diastolic and end-systolic right ventricular volumes were collected from a group of 6 conventional and 6 ... [more ▼]

Forty-one and 55 records of right-sided and systemic arterial pressures, cardiac output, and end-diastolic and end-systolic right ventricular volumes were collected from a group of 6 conventional and 6 double-muscled calves, respectively. In each group, the mean right ventricular pressure-volume loop was constructed. Global cardiac performance was significantly lower in the double-muscled than in the conventional calves. The right ventricular end-diastolic and end-systolic volumes, as well as the diastolic portion of the mean pressure-volume loop, were similar in the 2 groups. Those results suggest that the reduced cardiac performance of double-muscled calves is not due to a lowered ventricular preload and that diastolic properties of their myocardium are similar to those of conventional calves. When expressed on a body weight basis, however, the right ventricular end-diastolic and end-systolic volumes were lower in the double-muscled than in conventional calves. When expressed as a function of probable metabolic demand, therefore, the volumetric capacity of the cardiac pump appears to be reduced in double-muscled calves. The significantly lower right ventricular ejection fraction, maximal rate of ventricular pressure rise and right ventricular peak-systolic pressure to end-systolic volume ratio measured in double-muscled as compared with conventional calves suggest that reduced myocardial contractility may also be partly responsible for the significantly lower stroke index of the former calves. The cardiac pump of double-muscled cattle thus seems to be less effective than that of conventional cattle because of reduced volumetric capacity and lowered strength of contraction. [less ▲]

Effect of adenosine IV administration on gas exchanges and hemodynamics in unsedated calves with hypoxic vasoconstruction

in Pflügers Archiv : European Journal of Physiology (1995), 430

Reduced cardiac functional capacity as a consequence of the double-muscled conformation selection in the Belgian White and Blue breed.

in Bovine Practitioner (1995), 29

Pathophysiological response of bovine pulmonary function to gastric distension

in Journal of Comparative Pathology (1995), 112

The purpose was to determine whether gastric overdistension leads to lifethreatening perturbations of pulmonary gas exchange in healthy calves. Six animals were studied with normal (0 kPa) and increased ... [more ▼]

The purpose was to determine whether gastric overdistension leads to lifethreatening perturbations of pulmonary gas exchange in healthy calves. Six animals were studied with normal (0 kPa) and increased (1, 2, 3, 4 and 5 kPa) intragastric pressure (IGP). Changes in pleural pressures and peak expiratory flow paralleled those of IGP. Inspiratory pressure-time index remained stable throughout the insufflation process. Pulmonary function values were characterized by abrupt changes with increasing IGP. Tidal volume declined as IGP increased and, along with inspiratory flow, decreased abruptly with the highest pressure (5 kPa). Respiratory rate progressively increased up to an IGP of 4 kPa, then decreased by 30%, due to breath-holding at the end of inspiration. Minute volume increased with IGP up to 4 kPa, but dramatically declined at 5 kPa. Total pulmonary resistance remained stable throughout the insufflation process, whereas lung dynamic compliance fell abruptly to one-half of its baseline value at IGPs of 1 kPa and above. Arterial oxygen tension was maintained at an IGP of 1 kPa, slightly diminished at 2–3 kPa, and markedly decreased at 4–5 kPa. Hypercapnia and respiratory acidosis developed progressively with increasing IGP. Changes in arterial gases were probably due to a combination of (1) alveolar hypoventilation, caused by altered tidal to dead space volume ratio, inadequate central nervous system “drive”, altered effectiveness of inspiratory muscle action, or end-inspiratory breath-holding, and (2) ventilation to perfusion mismatch, caused by perfusion of collapsed lung units. In the range of IGPs used, standardized arterial pH did not decline below the control value, which suggests that perfusion of peripheral tissues remained sufficient, and that respiratory failure rather than cardiovascular failure may be the principal physiopathological effect of increased gastric pressure [less ▲]

Pulmonary Ventilation, Mechanics, Gas Exchange and Haemodynamics in Calves Following Intratracheal Inoculation of Pasteurella Haemolytica

in Zentralblatt für Veterinarmedizin. Reihe A (1995), 42(8), 531-544

A Pasteurella haemolytica A1 broth was injected intratracheally in eight calves and measurements of pulmonary function values (PFV) were made once before and hourly post inoculation (p.i.). Changes in ... [more ▼]

A Pasteurella haemolytica A1 broth was injected intratracheally in eight calves and measurements of pulmonary function values (PFV) were made once before and hourly post inoculation (p.i.). Changes in PFVs, included increased respiratory rate and minute ventilation (up to 158% of baseline 2 h p.i.) and decreased tidal volume and lung dynamic compliance (up to 33% of baseline 3 h p.i.). Total pulmonary resistance was not affected. At and after 3 h p.i. there was a progressive impairement of gas exchange, as judged from arterial O2 tension which decreased up to 65% of baseline. In contrast, arterial CO2 tension was not affected. Pulmonary hypertension was observed during the 3 last h of the study and was attributable to an increased pulmonary vascular resistance. Severe neutropenia was observed at 3 h p.i. and post-mortem histological findings were consistent with an acute fibrinohemorragic bronchopneumonia. In conclusion, P. haemolytica airway challenge unequiovocally resulted in acute pneumonia, providing a reproducible pathophysiological model for investigations regarding new therapeutic strategies. [less ▲]

Experimental production of hypocalcemia by EDTA infusion in calves : a critical appraisal assessed from the profile of blood chemicals and enzymes

in Comparative Biochemistry and Physiology. A : Comparative Physiology (1995), 110A(2), 115-130

Effect of type 2 antiserotonergic agent on altered cardiovascular function of hyperdynamic sepsis in newborn calves

in Proceedings of the 13th Comparative Respiratory Society Meeting (1994)