Decreased hypothalamic prostaglandin D2 and prostaglandin E2 contents during isoflurane anaesthesia in rats

This study was undertaken to evaluate the effect of isoflurane anaesthesia on the hypothalamic contents of both prostaglandin D₂ and E₂ which affect the sleep-wakefulness cycle. Sixty-three Wistar rats were divided into three equal groups, control, iso-flurane and recovery groups. Twenty-one rats of the control did not receive isoflurane. In the other groups 21 rats received isoflurane 2% far 30 min and 21 received isoflurane 2% for 30 min and were allowed to recover their usual behaviours, including righting reflex, spontaneously. The hypothalamus was removed and the contents of PGD₂ and PGE₂ were measured by enzyme immunoassay. The PGD₂ content in the hypothalamus was 397.9 ± 226.0 pg· g^{? 1} for the control group, 134.2 ± 41.2 pg· g^?1 for the isoflurane group and 269.1 ± 124.6 pg · g^?1 for the recovery group, respectively. The hypothalamic PGE₂ contents were 381.4 ± 139.0 pg · g^?1 for the control group, 183.3 ± 26.4 pg · g^?1 for the isoflurane group and 312.2 ± 96.0 pg · g^?1 for the recovery group, respectively. The hypothalamic PGD₂ and PGE₂ contents in the isoflurane group were lower (P < 0.05) than those in the control and recovery groups, while both the PGD₂ and PGE₂ contents of the control and the recovery groups were similar. We conclude that decreased hypothalamic PGD₂ and PGE₂ contents may be related to some manifestations of general anaesthesia with isoflurane.