Recording esophageal surface diaphragmatic action potentials after whole-nerve phrenic supramaximal activation : the breathing pattern-associated piftal

(1993)

Transdiaphragmatic Pressure Measurement in Cattle: Technical Data

in Research in Veterinary Science (1992), 53(2), 148-53

Techniques and methods required for accurate and reproducible measurements of transdiaphragmatic pressure (Pdi), were studied in seven-week and five-month-old calves. Since reliable pleural pressure ... [more ▼]

Techniques and methods required for accurate and reproducible measurements of transdiaphragmatic pressure (Pdi), were studied in seven-week and five-month-old calves. Since reliable pleural pressure measurement in cattle has already been described, separate experiments were conducted to compare retrodiaphragmatic pressures measured (i) with balloon-catheters and needle catheters, (ii) before and after eructation and (iii) in the ruminal and in the peritoneal cavities. Whereas respiratory-induced pressure changes were equally transmitted throughout the rumen content, a marked anteroposterior damping was observed as the recording site in the abdominal cavity was moved away from the diaphragm (P < 0.0001). It was concluded that the most appropriate and accurate way to measure Pdi changes in polygastric animals is to measure the pressure changes existing in the mid-thoracic portion of the oesophagus and in the liquid content of the rumen with balloon-tubing units. Neither growth- and diet-related rumen enlargement nor eructation, which are two typical characteristics of ruminants, altered the reliability of retrodiaphragmatic pressure measurements in the two age groups studied. [less ▲]

Effect of intravenous and aerosol administration of 5-hydroxytryptamine on pulmonary function values in healthy calves

in American Journal of Veterinary Research (1992), 53(3), 315-320

Effects of IV and aerosol administration of 5-hydroxytryptamine (5-HT) on ventilation, pulmonary mechanics values, pulmonary arterial pressure, and heart rate were investigated in healthy unsedated ... [more ▼]

Effects of IV and aerosol administration of 5-hydroxytryptamine (5-HT) on ventilation, pulmonary mechanics values, pulmonary arterial pressure, and heart rate were investigated in healthy unsedated Friesian calves. Minute volume increased significantly, mainly because of an increase in respiratory rate. Except for total pulmonary resistance after bolus injection, continuous administration of 5-HT given by either route caused significant alterations of lung dynamic compliance and total pulmonary resistance, the former decreasing to one-fifth of its baseline value and the latter increasing twofold. Pulmonary arterial pressure increased significantly, whatever the speed or route of administration. Administration of a bolus did not affect heart rate, whereas continuous IV administration of 5-HT as well by perfusion or by aerosol resulted in sustained tachycardia. It was concluded that 5-HT induces reversible bronchoconstriction and pulmonary vasoconstriction in healthy unsedated calves, 5-HT-induced functional alterations depend on the speed of administration, and excess of 5-HT production or depression in uptake by the lungs during bovine respiratory tract diseases could contribute to pulmonary dysfunction. [less ▲]

Influence of training on ventilatory and cardio-respiratory parameters measured during a standardised exercise in thoroughbred horses

in Proceedings of the 11th Comparative Respiratory Society Meeting (1992)

Training-induced changes in cardio-respiratory parameters during a standardised exercise in thoroughbred horses

in Archives Internationales de Physiologie et de Biochimie (1992)

Measurement of leg blood flow in calves by the thermodilution method : a technical study

in Archives Internationales de Physiologie et de Biochimie (1992)

La fatigue du diaphragme: un risque vital au cours des pneumonies ?

in Proceedings of the XVIIth World Buiatrics Congress (1992)

Effect of experimentally induced acute pneumonia on diaphragmatic strength generation in neonatal calves

in Archives Internationales de Physiologie et de Biochimie (1992)

Application of vectocardiography in cattle

in Proceedings of the XVIth World Buiatrics Congress (1992)

Bovine Vectocardiography: A Comparative Study Relative to the Validity of Four Tridimensional Lead Systems

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (1992), 39(6), 453-469

For spatial vectocardiography to become applicable for cardiac investigation in cattle, it was necessary to develop a reliable standardized electrocardiographic lead system in this species. In this study ... [more ▼]

For spatial vectocardiography to become applicable for cardiac investigation in cattle, it was necessary to develop a reliable standardized electrocardiographic lead system in this species. In this study, four tridimensional lead systems, initially developed in horses, were compared when applied in calves. Fifty seven electrocardiograms were collected. The between-subject variability of the magnitude and angles of the tridimensional P, QRS and T modal vectors obtained by use of each lead system was compared. Reproducibility of vectrocardiographic measurements was analyzed by comparing results obtained in 10 calves within a one day interval. The Holmes semi-orthogonal lead system, giving the lowest between-subject variability and the highest between-day reproducibility, appeared to be the most reliable lead system in order to apply vectocardiography in the bovine species. [less ▲]