How can body temperature and heart rate be maintained within the physiologic range?
Of all the determinants of infarct size, temperature is probably the most important. Accordingly, temperature should be strictly controlled throughout the experiment. We control temperature by adjusting the heating pad and the heat lamps during the surgical procedures. We allow a minimal drift in temperature, from 36.7 to 37.3C. As a result of these compulsive measures, rectal temperature remains within the physiological range in our studies (Table 2). With regard to heart rate, as mentioned earlier, pentobarbital anesthesia results in heart rates those are within the physiologic range for conscious mice (this range is from 500 to 760 beats/min) (Table 2). How to select the duration of reperfusion? In view of the added complexity inherent in following mice for 24 h after reperfusion, we investigated whether extending the reflow period beyond 4 h was important for assessing the final extent of infarct size. Birnbaum et al.7 have reported that at least 3 h of reperfusion are necessary to
