An investigation of the relationship between the liver and brain using an isolated perfused rat brain preparation

We have developed a new method for quantification of arteriolar hydraulic conductivity (Lp) from isolated rat brain vessels. The volume flux of water per unit surface area across the arteriole wall (Jv/S) was assessed from measurements of silicon oil drop movement within an occluded vessel at two to three pressures (between 20 and 70 mmHg); the Lp was derived from the slope of the relationship between Jv/S and applied pressure. Lp was measured in isolated cerebral arterioles 1) at room temperature (22 degrees C) without spontaneous vessel tone (control Lp; n = 11), 2) at room temperature with 10(-4) M adenosine (n = 5), and 3) at 37 degrees C with vessels dilated submaximally with 10(-4) M adenosine (n = 6). Lp at 22 degrees C without adenosine was 13.2 +/- 4.2 x 10(-9) (+/- SE) cm.s-1.cmH2O-1 for all vessels studied. Lp values ranged from 1.2 to 44.1 x 10(-9) cm.s-1.cmH2O-1 with a median value that was 5.9 x 10(-9) cm.s-1.cmH2O-1. Lp increased significantly (on average, 2.6-fold) with adenosine at 37 degrees C but not with adenosine at 22 degrees C. Control Lp bore no relationship to either the development of spontaneous tone or the diameter response to pH change, two recognized indicators of vessel viability.

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ABSENCE OF DIRECT ACTION OF INSULIN ON METABOLISM OF THE ISOLATED PERFUSED RAT BRAIN

Journal of Neurochemistry ◽

10.1111/j.1471-4159.1971.tb00225.x ◽

1971 ◽

Vol 18 (7) ◽

pp. 1269-1274 ◽

Cited By ~ 21

Author(s):

H. A. Sloviter ◽

H. Yamada

Keyword(s):

Rat Brain ◽

Direct Action ◽

Isolated Perfused Rat Brain

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Eicosanoids in Rat Brain during Ischemia and Reperfusion—Correlation to DC Depolarization

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1990.65 ◽

1990 ◽

Vol 10 (3) ◽

pp. 358-364 ◽

Cited By ~ 23

Author(s):

F. Tegtmeier ◽

C. Weber ◽

U. Heister ◽

I. Haker ◽

D. Scheller ◽

...

Keyword(s):

Arachidonic Acid ◽

Rat Brain ◽

Direct Current ◽

Eicosatetraenoic Acid ◽

Ischemia And Reperfusion ◽

Ischemic Time ◽

Isolated Perfused Rat Brain ◽

Current Potential

The effects of complete ischemia on cerebral arachidonic acid (AA) metabolism were investigated in the isolated perfused rat brain. During 12.5 min of ischemia, AA, 5-hydroxy-6,8,11,14-eicosatetraenoic acid, and 15-hydroxy-5,8,11,13-eicosatetraenoic acid increased 129-, 4-, and 10-fold, respectively, while subsequent reperfusion for 30 min resulted in normalized levels independently of the duration of preceding ischemia. Prostaglandin (PG) F2α, PGE2, PGD2, 6-keto-PGF1α, and thromboxane (Tx) B2 remained at preischemic levels during 12.5 min of complete ischemia. However, at the end of subsequent reperfusion for 30 min, the levels of the prostanoids PGF2α, PGE2, PGD2, 6-keto-PGF1α, and TxB2 increased according to the preceding ischemic time. The levels reached a maximum after 7.5 min of ischemia and were elevated by 7-, 14-, 48-, 3-, and 30-fold, respectively. A prolongation of ischemia of up to 12.5 min was not associated with further increases of prostanoids at the end of reperfusion. The mechanisms underlying the metabolism of eicosanoids are discussed in relation to the changes of cortical direct current potential.

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