Tissue distribution of penicillin during constant rate infusion in rats at 71 ATA.

Benzyl[14C]penicillin was infused at a constant rate of 100 mg X kg-1 X h-1 for 90 min in rats at 1 ATA air for the control group (n = 10) and at 71 ATA He-O2 for the pressure group (n = 11). The radioactivity was measured in the arterial blood, brain, liver, kidney, muscle, and fat. The mean brain penicillin concentration after 90 min infusion was approximately 20% increased at 71 ATA (P less than 0.05), but the brain: blood concentration ratio was not significantly affected. The mean blood, liver, and muscle penicillin content was slightly higher and the mean kidney content was slightly lower at pressure, but no statistically significant changes were observed.