XXXX : effect of @entity460 antagonists.

@entity1 @entity510 @entity235 @entity9085 @entity3931 @entity2473 @entity460 @entity594 @entity2553
The efficacy of the @entity460 antagonists @entity594 and @entity3931 was evaluated in a multiinjection @entity235 model of severe @entity2553 . Each of 21 adult mongrel @entity235 (15 to 20 kg) was assigned to one of four experimental groups. All animals received a total of 15 ml of fresh, unheparinized arterial blood via three cisterna magna injections. Selective left vertebral arteriography was performed 1 week before and exactly 7 days after the simulated @entity510 . Treatment with @entity460 antagonists was initiated at 24 hours and continued for 7 consecutive days. Comparisons were based on the percentage of @entity9085 diameter. On a milligram/kilogram basis, we used the manufacturer's maximal recommended daily dosages of @entity594 , whereas the dosages of @entity3931 used were 3 to 7 times greater than that reported to be therapeutically effective in reducing the incidence of severe deficits from @entity2553 in @entity1 with @entity510 . In this laboratory trial, systemic treatment with @entity460 antagonists did not prevent or significantly reduce chronic arterial narrowing. In the control group, @entity2473 reduced basilar artery diameter an average of 71% +/- 11 (SD). In the group treated with @entity594 , 10 mg orally every 6 hours, vessel diameter was reduced an average of 58% +/- 13%. In those animals treated with @entity3931 , 20 or 40 mg orally every 4 hours, the basilar artery diameter was decreased an average of 59% +/- 8 and 56% +/- 7, respectively. A preliminary trial using direct intracisternal administration of these agents demonstrated increased vessel diameter within 20 minutes in four of six animals, supporting other reports that this route of administration may prove more efficacious in the treatment of @entity2553 .
