The acute cerebrovascular effects of intracarotid adenosine in nonhuman primates.
In this study we sought to determine the acute cerebrovascular effects of intracarotid adenosine by using real-time cerebral blood flow (CBF) measurements in nonhuman primates. The internal carotid arteries of healthy anesthetized baboons were transfemorally cannulated. Changes in CBF were continuously measured at baseline and with 6 increasing doses of adenosine (0.002 to 1.5 mg/min) by use of an intraparenchymal thermal diffusion (TD) probe. Each infusion lasted 5 min. At baseline and at the largest dose of adenosine, CBF was also determined by the intraarterial (133)Xe technique. TD measurements revealed a dose-dependent increase in CBF from 32 +/- 6 mL x l00 g(-1) x min(-1) at baseline to 90 +/- 38 mL x l00 g(-1) x min(-1) with the largest dose of adenosine (n = 5; P < 0.0001). A similar magnitude of increase in CBF was also observed with (133)Xe CBF measurements. No significant increases in intracranial pressure or adverse systemic hemodynamic side effects were observed during adenosine infusion. The increase in CBF after adenosine lasted only for the duration of drug infusion. In conclusion, the transient cerebrovascular effects of intracarotid adenosine make it suitable for a trial of intraarterial vasodilator therapy and for controlled manipulation of cerebrovascular resistance.


CONCLUSIONS
Using a real-time cerebral blood flow (CBF) measurement technique, we evaluated the acute cerebrovascular effects of intracarotid adenosine in anesthetized baboons. The increase in CBF lasted only for the duration of the adenosine infusion. Adenosine might be a suitable drug for trial as an intraarterial vasodilator for the treatment of cerebral vasospasm.
Joshi
Shailendra
S
Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA. sj121@columbia.edu
Hartl
Roger
R
Wang
Mei
M
Feng
Lei
L
Hoh
Daniel
D
Sciacca
Robert R
RR
Mangla
Sundeep
S
D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D002343:Carotid Artery, Internal; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007269:Injections, Intra-Arterial; D007427:Intracranial Pressure / Q000187:drug effects; D008297:Male; D010215:Papio; D013238:Stereotaxic Techniques; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014980:Xenon Radioisotopes
D014665:Vasodilator Agents; D014980:Xenon Radioisotopes; D000241:Adenosine