Studies on reflex control of breathing in pigs and baboons.

In 8 pigs and 4 baboons, spontaneously breathing, anaesthetized with halothane, Hering-Breuer reflex was tested by means of a total obstruction of the airway preventing either inspiration or expiration. Subsequently animals were paralysed and maintained on phrenic nerve driven servo-respirator. The response of phrenic motoneurone output to various degree of lung inflation, introduced for one breath only, was then carefully studied. This was achieved by varying the gain of servorespirator. Additionally in baboons, identical series of gain manoeuvres was performed against a background of different levels of the initial gain setting. Changes in both inspiratory time and peak amplitude of phrenic signal were monoexponentially dependent on gain of servorespirator and linearly dependent on tidal volume (all negatively correlated). The relationship between inspiratory time T(1) and subsequent expiratory duration T(E )existed only within a range of growing T(1). Vagal positive feedback phenomenon was apparent in pigs and negligible in baboons. It is postulated that inspiratory cut-off mechanism terminates inspiration when excitatory function are outbalanced by their integral.

[1]  M. Noble,et al.  The direct effect on pulmonary stretch receptor discharge produced by changing lung carbon dioxide concentration in dogs on cardiopulmonary bypass and its action on breathing. , 1976, The Journal of physiology.

[2]  J. R. Romaniuk,et al.  The effects of CO2 on the components of breathing pattern. , 1976, Acta physiologica Polonica.

[3]  A. Guz,et al.  The effect of varying tidal volume on the associated phrenic motoneurone output:studies of vagal and chemical feedback. , 1975, Respiration physiology.

[4]  E. Phillipson.  Vagal control of breathing pattern independent of lung inflation in conscious dogs. , 1974, Journal of applied physiology.

[5]  A. Guz,et al.  Studies of the pulmonary vagal control of central respiratory rhythm in the absence of breathing movements , 1973, The Journal of physiology.

[6]  H. Gautier.  Respiratory responses of the anesthetized rabbit to vagotomy and thoracic dorsal rhizotomy. , 1973, Respiration Physiology.

[7]  G. Sant'ambrogio,et al.  The activity of lung afferent nerves during tracheal occlusion. , 1973, The Journal of physiology.

[8]  M. Mustafa,et al.  The effect of CO 2 upon discharge from slowly adapting stretch receptors in the lungs of rabbits. , 1972, Respiration physiology.

[9]  E. Bystrzycka,et al.  [Studies on the Hering-Breuer inflation and deflation reflex in rabbits]. , 1972, Acta physiologica Polonica.

[10]  F. J. Clark,et al.  On the regulation of depth and rate of breathing , 1972, The Journal of physiology.

[11]  S. C. Wang,et al.  Electrophysiologic basis for pontine apneustic center and its role in integration of the Hering-Breuer reflex. , 1967, Journal of neurophysiology.

[12]  A. Paintal.  Re-evaluation of respiratory reflexes. , 1966, Quarterly journal of experimental physiology and cognate medical sciences.

[13]  H. L. Davis,et al.  Effect of volume and rate of inflation and deflation on transpulmonary pressure and response of pulmonary stretch receptors. , 1956, The American journal of physiology.

[14]  Wyss Oa.  The mode of functioning of the respiratory centre. , 1954 .

[15]  T. Lumsden.  Observations on the respiratory centres , 1923, The Journal of physiology.

[16]  J. Feldman,et al.  Interaction of pulmonary afferents and pneumotaxic center in control of respiratory pattern in cats. , 1976, Journal of neurophysiology.

[17]  M. Głogowska.  The significance of afferent vagal information in the control of breathing in guinea pigs. , 1975, Acta neurobiologiae experimentalis.

[18]  J. Widdicombe,et al.  Studies on central respiratory activity in artificially ventilated rabbits. , 1973, Acta neurobiologiae experimentalis.

[19]  E. Schoener,et al.  Effect of hyperthermia and Pa CO2 on the slowly adapting pulmonary stretch receptor. , 1972, The American journal of physiology.

[20]  T. Larmi,et al.  [Regulation of respiration]. , 1954, Duodecim; laaketieteellinen aikakauskirja.