Simultaneous cerebral blood flow measured by direct and indirect methods

Michenfelder, John D.; Messick, Joseph M.; Theye, Richard A.

doi:10.1016/0022-4804(68)90111-x

Cited by 103 publications

(48 citation statements)

References 8 publications

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“…Based on the relative size of the vessels, this was estimated to contribute an insignificant per centage of the sagittal sinus flow. This is supported by the observations of Michenfelder et al (1968), who found that these veins made a negligible con tribution to sagittal sinus flow in the dog. The con tribution of the emissary veins to the sagittal sinus J Cereb Blood Flow Metab.…”

Section: Discussionsupporting

confidence: 70%

An Ultrasonic Doppler Venous Outflow Method for the Continuous Measurement of Cerebral Blood Flow in Conscious Sheep

Upton

Grant

Ludbrook

1994

J Cereb Blood Flow Metab

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Summary: A pulsed ultrasonic Doppler venous outflow method was developed for the continuous measurement of global cerebral blood flow (CBF) in conscious sheep, The sheep were prepared under anesthesia with a "suture down" -style ultrasonic flow probe on the dorsal sagittal sinus placed via a trephine hole, Angiographic and dye studies showed that the dorsal sagittal sinus at the point of placement of the probe collected the majority of the blood from the cerebral hemispheres, Studies of the blood velocity profile across the sinus showed that the dimen sions of the dorsal sagittal sinus changed minimally with changes in CBF in vivo. The velocity measurements were calibrated under anesthesia against an in vivo direct ve-

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Section: Discussionsupporting

confidence: 70%

An Ultrasonic Doppler Venous Outflow Method for the Continuous Measurement of Cerebral Blood Flow in Conscious Sheep

Upton

Grant

Ludbrook

1994

J Cereb Blood Flow Metab

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“…As a measure of cerebral blood flow, the cerebral venous outflow was determined following the method devised by Michenfelder et al (1968). It offers advantages over other direct-flow methods in that it causes minimal surgical disruption of the normal cerebrovascular anatomy and virtually eliminates extracerebral contamination.…”

Section: Resultsmentioning

confidence: 99%

“…The purpose of the present study was to establish a routine method for studying the effects of drugs on the cerebral circulation of the dog, the animal most commonly used in cardiovascular re-search. The technique of direct measurement of the canine cerebral blood flow as devised by Michenfelder, Messick & Theye (1968) was adopted. Several reference drugs with known effects on the human cerebral circulation, were studied on cerebral flow in relation to cerebral oxygen consumption, using the principle normally applied to the study of the drugs on the coronary circulation.…”

Section: Introduction Methodsmentioning

confidence: 99%

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Effects of drugs on the cerebral circulation of the dog in relation to the cerebral oxygen consumption

Chin

Imai

Nakano

et al. 1983

British J Pharmacology

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1Drug effects were studied on the cerebral circulation by measuring the sagittal sinus outflow in the anaesthetized dog following the method of Michenfelder and by monitoring cerebral oxygen consumption. Systemic aortic pressure, heart rate and spinal fluid pressure were also studied. 2 Since dilatation of cerebral vessels was observed in nearly all the preparations after inhalation of C02, it was thought that gross extracerebral contamination was virtually eliminated in this preparation. A close correlation was observed between the oxygen consumption of the brain as a whole and the sagittal sinus outflow (r= 0.93, P< 0.001); therefore it became feasible to differentiate the direct effects of drugs on cerebral blood vessels from indirect ones attributable to changes in the cerebral oxidative metabolism. 3 Sodium pentobarbitone (5 mg kg-1, i.v.), reduced the cerebral venous outflow and caused a decrease in the oxygen consumption. Pentylenetetrazol (30 mg kg -i.v.) and bemegride (5 mg kg-1 i.v.) produced an increase in the blood flow and a corresponding increase in the cerebral oxygen consumption. Thus, it was concluded these substances had no direct effects on the cerebral blood vessels. 4 Acetazolamide (10mgkg-1, i.v.), a carbonic anhydrase inhibitor, produced a marked and sustained vasodilatation after a latent period of 0.5-1 min. There was no increase in the cerebral oxygen consumption. A similar pattern was seen after CO2 had been inhaled. Methylergometrine and dihydroergotamine (20 jig kg-1 i.v.) induced a prolonged vasoconstriction of the cerebral vascular bed without any changes in the oxygen consumption of the brain. Therefore this method can discriminate between indirect or direct effects of drugs on cerebral vascular outflow.

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“…Measurement of the cerebral blood flow was conducted following the methods of Michenfelder et al (9) and Chin et al (10) (venous outflow method). Briefly, the head of the dog was fixed by ear bars in an upright position, the sagital sinus was exposed by a midline frontal-occipital incision, and a craniotomy was performed using a dental drill (Beaver-Labo, Osaka Electric).…”

Section: Methodsmentioning

confidence: 99%

Effects of calcium antagonists, felodipine and nicardipine, on cerebral circulation in dogs.

et al. 1990

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Abstract-The effects of a calcium antagonist of the dihydropyridine type, felodipine, on the cerebral circulation were studied in comparison with those of nicardipine in pancuronium-bromide immobilized unanesthetized dogs. Felodipine (0.3-10 iig/ kg. i.v.) and nicardipine (0.3-10 ,cig/kg, i.v.) produced a dose-related decrease in mean blood pressure with almost equal potencies.However, at a dose of 3 iig/kg, felodipine produced a more prominent increase in cerebral blood flow (CBF) than nicardipine.Decreases in cerebral vascular resistance were significantly greater in the felodipine group at doses of 0.3 and 3 /tg/kg, when compared with the nicardipine group.Cerebral oxygen consumption calculated by multiplying the arterio-venous difference of oxygen content by CBF was increased by these two drugs, but the changes were minimal. These data suggest that the increase in CBF produced by felodipine and nicardipine was primarily due to the direct dilatation of the cerebral blood vessels.

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Simultaneous cerebral blood flow measured by direct and indirect methods

Cited by 103 publications

References 8 publications

An Ultrasonic Doppler Venous Outflow Method for the Continuous Measurement of Cerebral Blood Flow in Conscious Sheep

An Ultrasonic Doppler Venous Outflow Method for the Continuous Measurement of Cerebral Blood Flow in Conscious Sheep

Effects of drugs on the cerebral circulation of the dog in relation to the cerebral oxygen consumption

Effects of calcium antagonists, felodipine and nicardipine, on cerebral circulation in dogs.

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