Responses of electrical potential, potassium levels, and oxidative metabolic activity of the cerebral neocortex of cats

Lothman, Eric W.; LaManna, Joseph Charles; Cordingley, Gary E.; Rosenthal, Myron; Somjen, George G.

doi:10.1016/0006-8993(75)90943-9

Cited by 192 publications

(74 citation statements)

References 46 publications

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“…5 and 11. 5 mm is in accordance with the observations of Lothman et al (1975), who studied the effects of local stimu lation on cerebral cortex in the cat. We did not ob serve steady-state Kp values above this range when mean gyral flow exceeded 14 ml 100 g-I min-I.…”

Section: Effects Of Occlusion On Kp and Relationships With Blood Flowsupporting

confidence: 91%

The Cortical Ischaemic Penumbra Associated with Occlusion of the Middle Cerebral Artery in the Cat: 1. Topography of Changes in Blood Flow, Potassium Ion Activity, and EEG

Strong

Venables

Gibson

1983

J Cereb Blood Flow Metab

150

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Summary:The gyral topography of the ischaemic penumbra associated with middle cerebral artery occlu sion was studied in cats; local blood flow (hydrogen clearance, 2-min initial slope analysis), pial surface potassium activity (Kp), and electroencephalogram (EEG) am plitude were recorded on the ectosylvian, su prasylvian, and marginal gyri, Penumbral conditions were defined as a reduction of EEG am plitude in the absence of a major increase in Kp, Whole hemisphere cerebral blood flow prior to occlusion was 35,6 ± llA (SD) mll00 g-l min-1 (n = 25), and fell significantly (p < 0.001) to 13.0 ± 4.7 (SD), 14.1 ± 6.6, and 23.8 ± 9.3 on ectosylvian, su prasylvian, and marginal gyri, respectively. Pre-occlusion Kp was 3.0 ± 0.9 mM (n = 53); sustained, steady-state increases in excess of 11.5 mM occurred in 5 of 7 (71%) experiments on ectosylvian gyrus, in 13 of 22 (59%) ex-

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Section: Effects Of Occlusion On Kp and Relationships With Blood Flowsupporting

confidence: 91%

The Cortical Ischaemic Penumbra Associated with Occlusion of the Middle Cerebral Artery in the Cat: 1. Topography of Changes in Blood Flow, Potassium Ion Activity, and EEG

Strong

Venables

Gibson

1983

J Cereb Blood Flow Metab

150

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show abstract

“…Our data also revenl that [Na + Ji remains elevated until the end of the [K * ],.-undershoot. This fact SUpl~rts previous, theoretical assumptions about the kinetics of intracdlular Na* [6,[10][11][12][13]16]. In a second series of experiments the contribution of the Na ÷ ,K ÷-pump to the [K * ]~-recovery phase was inv,-~, i~ated.…”

supporting

confidence: 80%

Intracellular free sodium and potassium, post-carbachol hyperpolarization, and extracellular potassium-undershoot in rat sympathetic neurones

Ballanyi

Grafe

Bruggencate

1983

Neuroscience Letters

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“…This inhibitory effect cannot be attributed to cell damage, because pro longed exposure to 2 mM furosemide does not change the membrane potential (Walz et aI., 1984). 1975; Lothman et al, 1975). Furosemide is an in hibitor of a transport system, involving a cation chloride carrier which probably can operate in var ious forms as a KCI, NaCI, or K,Na,2 CI carrier and may be involved in volume control (Geck et al, 1980; Aull, 1981, U berschar andBakker-Grunwald, 1983).…”

Section: Resultsmentioning

confidence: 99%

Intense Furosemide-Sensitive Potassium Accumulation in Astrocytes in the Presence of Pathologically High Extracellular Potassium Levels

Walz

Hertz

1984

J Cereb Blood Flow Metab

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An intense K+ accumulation in primary cultures of astrocytes, occurring when external K+ was increased from 5.4 to 54 m M, was investigated. This increase resulted in a doubling of the K+ content within 10 s. Thirty percent of the accumulation was inhibited by furosemide (2 m M). This drug had no effect on the unidirectional influx of K+ at 5.4 m M K+, but when the extracellular K+ concentration was increased, there appeared to be a furosemide-sensitive component of the influx. This component increased with increasing external K+ levels, reaching 44% of the total influx at 72 m M. These results show that astrocytes exhibit an intense furosemide-sensitive K+ accumulation which is activated by K+ levels resembling those occurring in the extracellular compartment during pathological events. Previous studies on a furosemide-sensitive Cl− pump in cultured astrocytes suggest that this accumulation might be via KCl cotransport, which in other systems is involved in volume control.

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Responses of electrical potential, potassium levels, and oxidative metabolic activity of the cerebral neocortex of cats

Cited by 192 publications

References 46 publications

The Cortical Ischaemic Penumbra Associated with Occlusion of the Middle Cerebral Artery in the Cat: 1. Topography of Changes in Blood Flow, Potassium Ion Activity, and EEG

The Cortical Ischaemic Penumbra Associated with Occlusion of the Middle Cerebral Artery in the Cat: 1. Topography of Changes in Blood Flow, Potassium Ion Activity, and EEG

Intracellular free sodium and potassium, post-carbachol hyperpolarization, and extracellular potassium-undershoot in rat sympathetic neurones

Intense Furosemide-Sensitive Potassium Accumulation in Astrocytes in the Presence of Pathologically High Extracellular Potassium Levels

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