Effects of single breath lung inflation on the pattern of subsequent breaths.
In rabbits, on release of lung inflations 0.4 to 3.3 times control VT and lasting 1 to 30 sec, VT, peak diaphragmatic activity (Ep) and inspiratory duration (Ti) increased, whereas expiratory duration (Te) decreased relative to pre-inflation values. Similar changes occurred between pre- and postinflation occluded breaths. These changes lasted from a few breaths up to 30 sec, and were positively correlated with magnitude and duration of inflations. Postinflation changes of pulmonary stretch receptor activity were relatively small and limited to 1-3 breaths. At chemical drive close to control: (a) postinflation VT vs Ti relationship moved to the right without changing its slope, Ti occluded eventually exceeding Ti after vagotomy; (b) the Te vs Ti relationship moved downwards, its slope being decreased and eventually abolished; (c) the average rate of rise of E was decreased. An increase of VT, Ep and Ti, and a decrease Te also occurred on release of stimulation of the central ends of the cut vagi producing apnea at FRC in mono- and bilateral vagotomized rabbits. Postinflation effects were mainly of central origin and tentatively explained as rebound phenomena within the respiratory center.
D000818:Animals; D002245:Carbon Dioxide / Q000097:blood; D003964:Diaphragm / Q000502:physiology*; D007839:Functional Laterality; D008168:Lung / Q000294:innervation*; D008465:Mechanoreceptors / Q000502:physiology; D010100:Oxygen / Q000097:blood; D012123:Pulmonary Ventilation; D011817:Rabbits; D012119:Respiration; D013997:Time Factors; D014628:Vagotomy; D014630:Vagus Nerve / Q000502:physiology*
D002245:Carbon Dioxide; D010100:Oxygen