Observations on the volume of blood flow and oxygen utilization of the carotid body in the cat

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Compared with the vast literature on the effects of sino-aortic reflexes upon the systemic circulation, few observations have been made on the haemodynamic events occurring in the pulmonary circulation.Schafer (1920) made the first observations using vagotomized rabbits breathing spontaneously. He found that electrical or mechanical stimulation of the aortic (depressor) nerve caused a fall in pulmonary arterial pressure which was followed by an after-rise above the initial level on cessation of the stimulus. Other workers have stimulated the central end of the vagus nerve in the dog and have usually obtained a rise in pulmonary arterial pressure

Section: Carotid Sinus and Pulmonary Circulation 223mentioning

confidence: 91%

The effects of stimulation of the carotid sinus baroreceptors upon the pulmonary arterial blood pressure in the dog

Daly¹,

Schweitzer²

1956

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“…Whether it is acetylcholine or the phenolic amine(s) which initiate the chemoreceptor impulse, or whether these agents subserve some quite different function within the carotid body, awaits clarification. Daly, Lambertsen & Schweitzer (1954) reported an 87 % increase in carotid body vascular resistance following stimulation of the cephalic end of the cut cervical sympathetic trunk, and according to Eyzaguirre & Lewin (1961) Burn & Rand, 1960).…”

Section: Discussionmentioning

confidence: 99%

The districution of biogenic amines in the carotid bifurcation region

Rees¹

1967

SUMMARY1. The distribution of phenolic amines in the carotid body and of adrenergic nerves in the arterial walls of the carotid bifurcation region was investigated histochemically using the phenolic amine-formaldehyde gas condensation reaction, with supplementary electron microscopical examination. Studies were conducted on normal rabbits and on rabbits after superior cervical ganglionectomy.2. The glomus cells of the carotid body contain phenolic amines. The cellular amine persists after long-term sympathetic ganglionectomy.3. The blood vessels supplying the carotid body receive an adrenergic innervation which disappears following superior cervical ganglionectomy.4. The walls of the carotid sinus contain adrenergic nerve fibres derived from the superior cervical ganglion.5. There is no penetration of the arterial tunica media by vasomotor fibres in any part of the carotid bifurcation region.6. Ultimate terminations of adrenergic nerves upon smooth muscle occur across the medio-adventitial border of the common, internal and external carotid arterial walls but only in relation to smooth-muscle cells in the adventitia of the carotid sinus wall.

“…That portion of the blood perfusing the carotid bodies drained into the internal and external jugular veins (Chungcharoen, M. de B. Daly & Schweitzer, 1952) and by inference from experiments on the cat (M. de B. Daly, Lambertsen & Schweitzer, 1954) would constitute a very small proportion of the total flow passing through the carotid bifurcation. Pump a perfused the carotid bodies with arterial blood from a reservoir attached to the left auricle.…”

Section: Methodsmentioning

confidence: 99%

The effects of stimulation of the carotid body chemoreceptors on pulmonary vascular resistance in the dog

Daly¹,

Daly²

1957

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In a previous study we investigated the effects of carotid sinus baroreceptor reflexes on pulmonary vascular resistance (Daly & Daly, 1957b, c). An examination has now been made of the reflex effects of stimulation of the carotid body chemoreceptors on the lesser circulation and the results which have been briefly reported elsewhere (Daly & Daly, 1957a) are presented in this paper. METHODSDogs of 14-7-19-6 kg body weight were anaesthetized with chloralose (0-1 g/kg intravenously) after premedication with morphine hydrochloride (1 mg/kg subcutaneously). The chest was opened in the mid-sternal line and the lungs ventilated by means of a Starling 'Ideal' pump at constant pressure, which varied from 8 to 15 cm water in different experiments. During expiration the lungs collapsed passively against a resistance of 2-2-5 cm water. Changes in tidal air volume were measured by the method of Konzett & Rossler (1940). Both phrenic and recurrent laryngeal nerves were crushed to minimize mechanical effects on the lungs.Perfusion of the carotid bodies. Reflex effects from the carotid body chemoreceptors were elicited by temporarily changing the perfusate from arterial blood to venous. For this purpose both carotid bifurcation regions were isolated from the circulation by ligation of all branches of the common and external carotid arteries. The veins draining the carotid bodies were, however, carefully preserved. Perfusion of the carotid sinus and body on both sides was carried out through the common carotid arteries. The arrangement of the two Dale-Schuster pumps used for the perfusion is shown in Fig. 1