MAC of I-653 in rats, including a test of the effect of body temperature and anesthetic duration.
The anesthetic potency of a new fluorinated volatile anesthetic, I-653, was tested preliminary to testing its toxic and metabolic characteristics in rats. The minimum alveolar concentration (MAC) of I-653 at 37.9 +/- 0.2 degrees C (mean +/- SD) in eight rats was 5.72 +/- 0.40%. In five rats, we reduced the rectal temperature to 28 degrees C in two steps of 5 degrees C. MAC decreased by 0.238 +/- 0.036% I-653 per degree centigrade decrease in temperature. That is, MAC decreased 42% as temperature decreased 10 degrees C. We restored the temperature to 38 degrees C and redetermined MAC. This value (5.66 +/- 0.75%) did not differ from the average MAC obtained before hypothermia (5.84 +/- 0.36%).
D000769:Anesthesia, Inhalation; D000777:Anesthetics; D000818:Animals; D001831:Body Temperature; D002849:Chromatography, Gas; D000077335:Desflurane; D007530:Isoflurane / Q000031:analogs & derivatives*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D000777:Anesthetics; D000077335:Desflurane; D007530:Isoflurane