Action of Lobeline on Pulmonary Artery Mechanoreceptors of the Cat.
نویسندگان
چکیده
• Two recent independent experimental studies have found evidence that ventilation may be modified by changes in the pulmonary vascular bed. Firstly, small amounts of lobeline injected intravenously initiate reflex depression of ventilation mainly from the extrapulmonary parts of the pulmonary arteries of the cat.' Larger doses elicit, in addition, cardiovascular changes, bradycardia, and hypotension. Secondly, a fairly rapid reduction of pressure in the pulmonary vascular bed produces a reflex increase in rate and depth of ventilation in the dog. This reflex appears to be tonically active in the normally ventilating animal. A subsequent collaborative study showed that this reflex ventilatory response also occurred in the cat and demonstrated that the afferent pathways for these ventilatory changes have many common features. It was found that a variety of experimental changes (viz. vagal cooling, procaine infusion, and the administration of small amounts of pentobarbital) each affected the ventilatory response to either stimulus (viz. a fall in pulmonary artery pressure and lobeline) very similarly, and distinguished them unequivocally from the pathways for the reflex ventilatory responses phenyldiguanide and veratridine. Both these drugs affect other intrathoracic sensory endings to cause reflex changes in ventilation. This evidence suggested tentatively that reflex changes in ventilation could be initiated by changes in pressure probably confined to the extrapulmonary parts of the pulmonary arteries. This region in the dog contains most of the pulmonary artery mechanoreceptors
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عنوان ژورنال:
- Circulation research
دوره 17 شماره
صفحات -
تاریخ انتشار 1965