Changes in Systemic Blood Pressure Alter Local Cerebral Blood Flow Following Blood-Brain Barrier Injury

1988 ◽  
Vol 529 (1 Fourth Colloq) ◽  
pp. 286-287
Author(s):  
WALTER D. JOHNSON ◽  
THOMAS H. MILHORAT ◽  
DIANA DOW-EDWARDS
1981 ◽  
Vol 1 (3) ◽  
pp. 349-356 ◽  
Author(s):  
A. M. Harper ◽  
L. Craigen ◽  
S. Kazda

The effect of the calcium antagonist nimodipine was tested in anaesthetised primates. A rapid intravenous injection of 3 or 10 μg kg−1 produced a transient rise in end-tidal Pco2 and a fall in arterial blood pressure, but 10 min after the injection there was no significant change in CBF. A continuous intravenous infusion of 2 μg kg−1 min−1 caused a modest fall in mean arterial blood pressure and an increase in cerebral blood flow (CBF), which gradually increased to 27% above control after 50 min infusion. There was no significant change in CMRO2. A continuous intracarotid infusion of 0.67 μg kg−1 min−1 caused an increase in CBF of between 46 and 57%. This was further increased to 87% above control after disruption of the blood-brain barrier with hyperosmolar urea. Thirty minutes after the urea, the CBF returned to 43% above control. Twenty minutes after the infusion of nimodipine had been stopped, the CBF had returned to control values. EEG studies in this group showed no obvious increase in electrocortical activity. This evidence suggests that nimodipine has no effect on cerebral metabolism but increases CBF, particularly after disruption of the blood-brain barrier.


1978 ◽  
Vol 234 (1) ◽  
pp. H59-H66 ◽  
Author(s):  
O. Sakurada ◽  
C. Kennedy ◽  
J. Jehle ◽  
J. D. Brown ◽  
G. L. Carbin ◽  
...  

The autoradiographic diffusible tracer technique for the measurement of local cerebral blood flow was originally designed for use with the radioactive, inert gas 131I-labeled trifluoroiodomethane and is applicable only with tracers that exhibit unrestricted diffusion through the blood-brain barrier. Because of the technical problems associated with the use of gaseous tracers, a suitable nonvolatile tracer has been sought. [14C] Antipyrine has been used previously and found to be unsuitable because of limitations in its diffusion through the blood-brain barrier. An analogue of [14C]antipyrine, iodo [14C]antipyrine, exhibits higher partition coefficients than [14C]antipyrine between nonpolar solvents and water and might, therefore, be expected to diffuse more freely through the barrier. Its use as the tracer in the local blood flow technique leads to values considerably above those obtained with [14C]antipyrine in the rat and cat and essentially the same as those obtained with the gas trifluoro[131I]iodomethane in the cat. Iodo[14C]antipyrine appears, therefore, to be a satisfactory nonvolatile tracer for the measurement of local cerebral blood flow.


1984 ◽  
Vol 4 (1) ◽  
pp. 96-102 ◽  
Author(s):  
R. Suzuki ◽  
C. Nitsch ◽  
K. Fujiwara ◽  
I. Klatzo

Interrelationship between the breakdown of the blood–brain barrier (BBB) to Evans blue and elevations in the regional cerebral blood flow (rCBF) was studied in rabbits subjected to adrenaline- or metaraminol-induced systemic hypertension and also in bicuculline-induced seizures. The rCBF was assessed in small samples from various regions of the brain with the use of [3H]nicotine, and the permeability of the BBB was evaluated with an Evans blue tracer. In acute hypertension, Evans blue extravasations were observed in the occipital cortex and sometimes in the superior colliculus, i.e., the regions which also showed the highest elevations in rCBF. The breakdown of the BBB in acute hypertension was clearly related to the rate of mean arterial blood pressure rise, being much less pronounced in the metaraminol group, which showed a much slower blood pressure elevation rate. In bicuculline-induced seizures, there was no evident correlation between the amplitude of rCBF elevations and Evans blue extravasations. Preservation of BBB integrity was observed in areas showing high elevations in the rCBF.


1996 ◽  
Vol 18 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Hiroki Namba ◽  
Toshiaki Irie ◽  
Kiyoshi Fukushi ◽  
Masaomi lyo ◽  
Takahiro Hashimoto ◽  
...  

1979 ◽  
Vol 237 (2) ◽  
pp. H178-H184 ◽  
Author(s):  
S. M. Mueller ◽  
D. D. Heistad ◽  
M. L. Marcus

The purpose of this study was to determine the effect of activation of sympathetic pathways during seizures on cerebral blood flow and integrity of the blood-brain barrier. We measured cerebral blood flow with microspheres and disruption of the blood-brain barrier with labeled albumin in cats. One cerebral hemisphere was denervated by cutting the superior cervical sympathetic trunk on one side. During bicuculline-induced seizures, superior cervical sympathetic nerve activity increased about threefold. Blood flow to the innervated hemibrain was significantly lower than flow to denervated hemibrain. However, in relation to the total increase in flow, this effect of nerves was minor. Blood-brain barrier permeability increased about sixfold during seizures, but there was no difference between the innervated and denervated sides of the brain. We conclude that sympathetic nerves attenuate the increase in cerebral blood flow during seizures, despite the increase in metabolism, but this effect is small. Activation of sympathetic nerves does not reduce disruption of the blood-brain barrier during seizures.


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