Cell cycle in mouse intestinal crypts during halothane or nitrous oxide anaesthesia.

The effects of inspired air, halothane 0.5% and nitrous oxide 64% on the cell cycle were examined by autoradiography in the duodenal and jejunal crypts of mice. The length of cell cycle phases was calculated from the rate of transition of the labelled cells from the DNA-synthetic to the mitotic phase, using a computer program based on a mathematical model of the cell cycle. The computer analysis showed that halothane 0.5% prolonged the post-mitotic gap by 57% in the duodenum and by 60% in the jejunum. The DNA-synthetic time was prolonged by 23% in the duodenum and 30% in the jejunum and the mitotic time by 33% in the duodenum and 46% in the jejunum, when compared with the control animals breathing air. Nitrous oxide 64% had no effect on the cell cycle.