If animal is dying within 2 to 4 hr It may depends upon anesthesia you used for experiment and their dose. It is always better to use gaseous anesthesia for quick recovery. High amount of sucrose may cause dizziness, unconsciousness but exactly death will occur, I am not confirm.

Thank you for your answer.

The problem is that animals died after 12-14 hours. Also this animals were old (18-24 mounts).

Thank you again for your response!

Bogdan

Last time i forget to mentioned that age of mice should be 8-10 week; for rat it should be 16-20 week other wise their tolerance towards stroke is less. So, this may be one of the reason for dying of animal. Old rat having less survival rates.

Thank you for your answer! Do you have a reference for this information?

Bogdan Catalin

In a comparison study of brain damage in male vs female Wistar rats after reversible MCAO, the overnight survival rate was 71% for males (n =28) and 50% for females (n = 32). There was no significant difference in survival rate between sexes (Chi Squares with post hoc Fisher's Exact Tests). Transient focal ischemia was induced by MCAO according to Zea-Longa method as modified by Belayev. Procedures were performed while animals were under 1.5% isoflurane anesthesia. Wistar rats were supplied by Hilltop Laboratories, Scottsdale, PA. Ages were not recorded, but weights may serve as a surrogate marker for age as all rats were received simultaneously from the breeder. The animals included in the final analysis of data were 11 male rats weighing 270-302 g, mean 288.2 +/- 2.2 g and 13 females weighing 259-295 g, mean 273.0 +/- 3.0 g. As would be expected for age matched animals, the males weighed significantly more than the females.