Vasodilatory effect of adenosine triphosphate does not change cerebral blood flow: a PET study with (15)O-water.
OBJECTIVE
Adenosine triphosphate (ATP) is the parent compound of adenosine and well known as a powerful vasodilator. To investigate the effect of ATP on cerebral blood flow (CBF) and cerebral vessels, (15)O-water positron emission tomography (PET) studies were performed to evaluate changes in CBF and blood volume before and after ATP administration.


METHODS
Ten healthy young volunteers underwent (15)O-water PET scans under the conditions of baseline, 3 and 1 min after ATP continuous infusion. CBF values in cortical regions of the bilateral middle cerebral arteries and basal ganglia were obtained for each subject. Statistical parametric mapping (SPM) was applied for analysis of regional changes. Physiologic parameters, such as blood gas and blood pressure were also measured.


RESULTS
Cortical CBF showed no significant change after continuous infusion of ATP compared with the baseline. Dilatation of major vessels induced by ATP was visualized on SPM analysis. Heart rates increased and mean blood pressure decreased during ATP administration while blood gas data showed no changes between the different conditions.


CONCLUSIONS
Intravenous ATP administration caused dilatation of major cerebral vessels but no significant change in CBF under normoventilation and decrease in systemic blood pressure, indicating that this no change in CBF under vasodilatory effect of ATP may be caused by cerebral microvascular autoregulation.
Hussain
Raihan
R
Biomedical Imaging Research Center (BIRC), University of Fukui, 23-3 Shimoaizuki, Matsuoka, Eiheiji-cho, Fukui, 910-1193, Japan.
Tsuchida
Tatsuro
T
Kudo
Takashi
T
Kobayashi
Masato
M
Tsujikawa
Tetsuya
T
Kiyono
Yasushi
Y
Fujibayashi
Yasuhisa
Y
Okazawa
Hidehiko
H
D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002536:Cerebral Arteries / Q000187:drug effects / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D003326:Coronary Circulation / Q000187:drug effects; D006321:Heart / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography; D015899:Tomography, Emission-Computed, Single-Photon; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014867:Water / Q000737:chemistry; D055815:Young Adult
D010104:Oxygen Radioisotopes; D014867:Water; D000255:Adenosine Triphosphate