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Forrester T, Harper AM, MacKenzie ET, Thomson EM. Effect
of adenosine triphosphate and some derivatives on cerebral blood flow
and metabolism. J Physiol. 1979;Nov;296:343-355.
Responses of cerebral blood vessels to peri- and intravascular
doses of ATP (adenosine triphosphate) and some derivatives were studied
in cat and baboon. 2. Perivascular application of ATP to cat pial arterioles
gave a threshold dilatory effect at a concentration of 10(-11) M. This
figure is comparable to the amount of ATP calculated to be released from
electrically stimulated brain slices. 3. It is concluded that adenine
nucleotides have a major role to play in the local control of cerebral
blood flow. 4. Intracarotid injection of ATP showed a calculated threshold
effect at 4 x 10(8) M in the cat and 4 x 10(-9) M in the baboon. 5. The
threshold response of the vasculature to intracarotid adenosine lay between
4 x 10(-7) M and 4 x 10(-6) M in the baboon. Little effect was produced
with AMP, pyrophosphate and inorganic phosphate. 6. Intracarotid ATP
increased the oxygen consumption of the baboon brain parenchyma. This
effect was attributed in part to an elevation of the cellular cyclic
AMP levels. 7. Osmotic disruption of the blood-brain barrier in baboon
did not affect the vasodilatory or metabolic effect of intracarotid ATP.
8. It is postulated that circulating purine compounds mediate a form
of metabolic communication inthe body. Also, release of purine compounds
from active local nerves might influence cerebral blood flow.
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Abstracts