Cerebral Circulation and Metabolism in Pulmonary Emphysema and Fibrosis With Observations on the Effects of Mild Exercise 1

Scheinberg, Peritz; Blackburn, I.; Saslaw, Milton S.; Rich, M.; Baum, Gerald L.

doi:10.1172/jci102786

Cited by 31 publications

(21 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…CBF values within normal limits. 6 In line with these data, we found that patients with chronic hypercapnia presented MCA flow velocities similar to those of normal subjects.…”

Section: Resultssupporting

confidence: 86%

“…3.4 The CBF-PaC0 2 relationship is even more complex, for the brain Pco, affects the activity of nervous structures that regulate pulmonary ventilation," Yet, in the advanced stages of respiratory failure secondary to chronic obstructive lung disease, stable hypercapnia is known to be associated with a normal CBF. 6 Middle cerebral artery blood flow velocity can be measured by means of transcranial Doppler ultrasound." Since the diameter of the large cerebral arteries is known to remain constant during hypercapnia, 8 …”

mentioning

confidence: 99%

See 1 more Smart Citation

Cerebral Vascular Responsiveness in Chronic Hypercapnia

Clivati

Ciofetti

Cavestri

et al. 1992

Chest

View full text Add to dashboard Cite

“…CBF values within normal limits. 6 In line with these data, we found that patients with chronic hypercapnia presented MCA flow velocities similar to those of normal subjects.…”

Section: Resultssupporting

confidence: 86%

mentioning

confidence: 99%

Cerebral Vascular Responsiveness in Chronic Hypercapnia

Clivati

Ciofetti

Cavestri

et al. 1992

Chest

View full text Add to dashboard Cite

“…The discrepancies between the findings of CMRO 2 alterations during the transition from rest to exercise may be ascribed to different exercise intensities. During exercise at mild to moderate intensity, CMRO 2 is unchanged compared with rest (18,23,37,43), whereas more vigorous exercise results in an increased oxygen uptake of the brain (36). The workload in the present study was identical in the two trials, and it was not altered during the exercise period.…”

Section: Discussionmentioning

confidence: 48%

Effects of hyperthermia on cerebral blood flow and metabolism during prolonged exercise in humans

Nybo

Møller

Volianitis

et al. 2002

Journal of Applied Physiology

190

197

View full text Add to dashboard Cite

The development of hyperthermia during prolonged exercise in humans is associated with various changes in the brain, but it is not known whether the cerebral metabolism or the global cerebral blood flow (gCBF) is affected. Eight endurance-trained subjects completed two exercise bouts on a cycle ergometer. The gCBF and cerebral metabolic rates of oxygen, glucose, and lactate were determined with the Kety-Schmidt technique after 15 min of exercise when core temperature was similar across trials, and at the end of exercise, either when subjects remained normothermic (core temperature = 37.9 degrees C; control) or when severe hyperthermia had developed (core temperature = 39.5 degrees C; hyperthermia). The gCBF was similar after 15 min in the two trials, and it remained stable throughout control. In contrast, during hyperthermia gCBF decreased by 18% and was therefore lower in hyperthermia compared with control at the end of exercise (43 +/- 4 vs. 51 +/- 4 ml. 100 g(-1). min(-1); P < 0.05). Concomitant with the reduction in gCBF, there was a proportionally larger increase in the arteriovenous differences for oxygen and glucose, and the cerebral metabolic rate was therefore higher at the end of the hyperthermic trial compared with control. The hyperthermia-induced lowering of gCBF did not alter cerebral lactate release. The hyperthermia-induced reduction in exercise cerebral blood flow seems to relate to a concomitant 18% lowering of arterial carbon dioxide tension, whereas the higher cerebral metabolic rate of oxygen may be ascribed to a Q(10) (temperature) effect and/or the level of cerebral neuronal activity associated with increased exertion.

show abstract

“…Only 13 studies have examined CBF and the metabolic rates of oxygen, glucose and lactate during incremental exercise (Kleinerman & Sokoloff, ; Scheinberg et al . , ; Kleinerman & Sancetta, ; Lambertsen et al . ; Madsen et al .…”

Section: Introductionmentioning

confidence: 99%

Regulation of cerebral blood flow and metabolism during exercise

Smith

Ainslie

2017

Experimental Physiology

249

230

View full text Add to dashboard Cite

What is the topic of this review? The manuscript collectively combines the experimental observations from >100 publications focusing on the regulation of cerebral blood flow and metabolism during exercise from 1945 to the present day. What advances does it highlight? This article highlights the importance of traditional and historical assessments of cerebral blood flow and metabolism during exercise, as well as traditional and new insights into the complex factors involved in the integrative regulation of brain blood flow and metabolism during exercise. The overarching theme is the importance of quantifying cerebral blood flow and metabolism during exercise using techniques that consider multiple volumetric cerebral haemodynamics (i.e. velocity, diameter, shear and flow). Cerebral function in humans is crucially dependent upon continuous oxygen delivery, metabolic nutrients and active regulation of cerebral blood flow (CBF). As a consequence, cerebrovascular function is precisely titrated by multiple physiological mechanisms, characterized by complex integration, synergism and protective redundancy. At rest, adequate CBF is regulated through reflexive responses in the following order of regulatory importance: fluctuating arterial blood gases (in particularly, partial pressure of carbon dioxide), cerebral metabolism, arterial blood pressure, neurogenic activity and cardiac output. Unfortunately, the magnitude that these integrative and synergistic relationships contribute to governing the CBF during exercise remains unclear. Despite some evidence indicating that CBF regulation during exercise is dependent on the changes of blood pressure, neurogenic activity and cardiac output, their role as a primary governor of the CBF response to exercise remains controversial. In contrast, the balance between the partial pressure of carbon dioxide and cerebral metabolism continues to gain empirical support as the primary contributor to the intensity-dependent changes in CBF observed during submaximal, moderate and maximal exercise. The goal of this review is to summarize the fundamental physiology and mechanisms involved in regulation of CBF and metabolism during exercise. The clinical implications of a better understanding of CBF during exercise and new research directions are also outlined.

show abstract

Cerebral Circulation and Metabolism in Pulmonary Emphysema and Fibrosis With Observations on the Effects of Mild Exercise 1

Cited by 31 publications

References 10 publications

Cerebral Vascular Responsiveness in Chronic Hypercapnia

Cerebral Vascular Responsiveness in Chronic Hypercapnia

Effects of hyperthermia on cerebral blood flow and metabolism during prolonged exercise in humans

Regulation of cerebral blood flow and metabolism during exercise

Contact Info

Product

Resources

About