Regional brain blood flow in swine following T-2 toxin administration.
Three groups of swine (6/group) were used to assess alterations in regional brain blood flow induced by T-2 toxin. One group served as vehicle (70% ethanol) control, and groups were dosed intravascularly with T-2 toxin at 0.6 or 2.4 mg/kg body weight. Cerebral, cerebellar, and brain stem blood flows were evaluated at 0 h (predosing) and at 90-min intervals for 6 h postdosing. Fifteen-micron diameter radionuclide labeled microspheres were used to determine blood flow. Hemodynamic variables were determined at the same time points. The infusion of T-2 toxin resulted in dose-dependent reductions in both cardiac index and mean arterial pressure, accompanied by significant increases in heart rate. In animals given the lower dose of T-2 toxin, significant reductions in blood flow were evident in the cerebrums and cerebellum but not in the brain stem. Reductions in blood flow to all regions of the brain were evident in those animals given 2.4 mg T-2 toxin/kg. Brain blood flow was less severely compromised than was cardiac output, suggesting intact local autoregulation.
Lundeen
G R
GR
Pfizer Central Research, Groton, CT 06340.
Poppenga
R H
RH
Beasley
V R
VR
Manuel
R K
RK
Buck
W B
WB
Tranquilli
W J
WJ
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000187:drug effects*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D013552:Swine; D013605:T-2 Toxin / Q000633:toxicity*
D013605:T-2 Toxin