The regulation of normal breathing

Douglas, C. G.; Haldane, J. B. S.

doi:10.1113/jphysiol.1909.sp001315

Cited by 95 publications

(36 citation statements)

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“…Table I gives results obtained from a rabbit with gas under its skin and in its abdominal cavity. The It will be seen that the changes, produced by exercise, in the C02-tensions in gas under the skin and in the abdominal cavity of the rabbit were similar to the course of events found by Douglas and Haldane (6) to occur in the alveolar C02-tension in man, viz. that after exercise there is first an increasing C02-tension then a fall below normal level and then a gradual return to normal; and that after each successive exercise period the rise is less than in the preceding period.…”

Section: J a Campbellsupporting

confidence: 73%

The dissociation of oxyhæmoglobin in the tissues

Campbell¹

1925

The Journal of Physiology

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From these results it has been deduced that in severe exercise the increase of the H-ion concentration consequent on the formation of lactic acid causes an easier liberation of 02 from Hb and thus to some extent counterbalances the decreased 02-saturation of the Hb. It seemed possible that the effect thus deduced might be demonstrated in a living animal by injecting gas under the skin and into the abdominal cavity and observing the changes which severe muscular exercise produces in the 02-tensions of the gas.Method. The technique has already been fully described (5). Nitrogen was injected in moderate amount, under the slkn of the back and into the abdominal cavity of a rabbit and left there two or three days until the C02-and 02-tensions of the gas had come into equilibrium with the tensions in the surrounding tissue spaces. Then about 10 c.c. were withdrawn at intervals during the experiments without anaesthesia and analysed in the Haldane apparatus. The needles used to withdraw samples of gas from the abdominal cavity and from under the skin were about two inches in length, those for the abdominal cavity had an external diameter of *025 inch, those for the skin being wider, *035 inch in external diameter. The air space of these needles was reduced to a minimum and stilettes were used for the abdominal cavity. The animal was excited to make movements of trying to escape by taking hold of one, or two, of its legs once every five seconds or so. Most of its body muscles were thus exercised. Some animals, less tame than others, performed more strenuous exercise. Obvious hyperpncea PH. LIX. 26

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Section: J a Campbellsupporting

confidence: 73%

The dissociation of oxyhæmoglobin in the tissues

Campbell¹

1925

The Journal of Physiology

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“…It is not a novel concept that even small differences in H ϩ ion may explain the large changes in ventilation detected on exercise. 27 We cannot exclude the possibility that incomplete diffusion of protons meant that the differences we detected were smaller than the true difference in pH at the receptor site within the muscle.…”

Section: Present Studymentioning

confidence: 83%

Skeletal Muscle Reflex in Heart Failure Patients

et al. 2003

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Background-An important role of the increased stimulation of skeletal muscle ergoreceptors (intramuscular afferents sensitive to products of muscle work) in the genesis of symptoms of exertion intolerance in chronic heart failure (CHF) has been proposed. With the use of selective infusions and dietary manipulation methods, we sought to identify the role of H ϩ , K ϩ , lactate, and peripheral hemodynamics on ergoreflex overactivation. Methods and Results-Ten stable CHF patients (aged 67.9Ϯ2.5 years, peak oxygen uptake 16.3Ϯ1.2 mL · kg Ϫ1 · min Ϫ1 ) and 10 age-matched and sex-matched healthy subjects were studied. The ergoreflex contribution to ventilation was assessed by post-handgrip regional circulatory occlusion (PH-RCO) and computed as the difference in ventilation between PH-RCO and a control run without PH-RCO. This test was performed on 6 separate occasions. On each occasion a different chemical was infused (insulin, sodium nitroprusside, sodium bicarbonate, dopamine, or saline) or a 36-hour glucose-free diet was undertaken before the test. During all stages of the protocol, the local muscular blood effluent concentrations of H ϩ , K ϩ , glucose, and lactate were assessed. An ergoreflex effect on the ventilatory response was seen in patients (versus control subjects) during the saline infusions (6.7Ϯ2.3 L/min versus Ϫ0.1Ϯ0. Key Words: heart failure Ⅲ muscles Ⅲ nervous system, autonomic Ⅲ reflex Ⅲ ventilation T he ergoreflex consists of a brain stem autonomic and ventilatory response activated by signals from the periphery, such as free nerve ending group III and IV muscle afferents. 1 It has been hypothesized that muscle metabolic abnormalities and/or circulatory insufficiencies of chronic heart failure (CHF) cause local overproduction and accumulation of muscle metabolic products, which trigger the ergoreceptors. 2,3 Our lab and others have confirmed this hypothesis by demonstrating that the muscle ergoreflexes of the forearm muscles, 4 the small muscles used in dorsiflexing the foot, 5 and the muscles of the quadriceps 6 cause an enhanced ventilatory response in CHF. An overactivation of the muscle ergoreflex during exercise has been shown to be closely related to patient symptoms and to the ventilatory response to exercise, and a role of this reflex in contributing to exercise intolerance in CHF has been proposed. 4 The triggering mediators responsible for the ergoreflex stimulation and their involvement in the abnormal exercise responses in CHF remain to be established. Different metabolic and humoral products have been studied in animals [7][8][9][10][11][12] and in humans, 13-15 but few investigators have investigated factors specifically involved in the ergoreflex overactivation of CHF patients. 16,17 One (or more) of these mediators may be involved as a link between alterations in muscle metabolism and/or hemodynamics present in CHF and the ventilatory response to exercise, via activation of muscle reflex.We have investigated the role of the putative triggers in muscle ergoreflex activation. The id...

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“…Gasping is also nearly universal at the beginning and end of life. Although these phenomena are literally of vital interest to human physiology and clinical medicine, they have rarely been studied in man, except for posthyperventilation apnea (1,2). Animal studies of apnea and gasping are infrequent as well, and usually include experiments on fetuses, inReceived for publicationt 25 September 1974 and in revised form 12 Autgust 1975. volving the first breath.…”

Section: Introductionmentioning

confidence: 99%

Hypoxic apnea and gasping.

Guntheroth¹,

Kawabori²

1975

J. Clin. Invest.

135

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We have tested the hypothesis that severe hypoxia causes apnea, regardless of the arterial COa and pH, and that extreme hypoxia causes gasping. Acute experiments with airway occlusion and with low inspired oxygen (FIo2) were performed on anesthetized adult dogs and monkeys. Arterial oxygen saturation was recorded continuously with fiberoptic oximetry, and Pcoa by an electrode catheter. In addition, blood samples were obtained for Po2, Pco2, and pH. Apnea was induced regularly when the Pao2 fell below 10 torr, whether the Paco2 was high with asphyxia (63 torr) or low (26 torr) with low FIo2. Similarly, the Pao2 at apnea was the same whether the pH was 7.17 with asphyxic hypoxia or 7.46 with hypoxic hypoxia. Gasping occurred at even lower Pao2 (below 5 torr) after 1 or 2 min of apnea. Gasping promptly restored the Paoa to levels of moderate hypoxia (over 30 torr) which permitted resumption of regular respiration, with gradual elimination of the gasping. Fetal monkeys at term were studied in a similar manner from the moment of cord clamping. Their blood gases with apnea were quite similar to adult values in the narrow range of Pao2 and the wide range of Paco2 and pH. In the fetus, gasping was less immediately effective in improving arterial oxygen, but more persistent than in the adult. Regular respirations would not develop in the absence of oxygen in either the fetus or adult animal.

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The regulation of normal breathing

Cited by 95 publications

References 0 publications

The dissociation of oxyhæmoglobin in the tissues

The dissociation of oxyhæmoglobin in the tissues

Skeletal Muscle Reflex in Heart Failure Patients

Hypoxic apnea and gasping.

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