Pharmacological actions of intracerebrally administered polyamines in mice

Pharmacological actions of spermidine (SPD) and spermine (SPM) in mice given these polyamines by intracerebral injection (i.c.) were investigated. The spontaneous motor activity (SMA) assessed by the photocell counter method did not change immediately following injection of 80 mug SPD, but was enhanced 24 hours after the injection of 40 or 80 mug. A significant decrease of SMA was not immediately evident after the administration of 40 mug SPM but was demonstrated 24 hours later. Mice given single doses of 20 mug SPD exhibited increase in weight gain and those given 40 mug showed no significant difference, whereas a conspicuous decrease in weight occurred in mice given 80 mug of SPD. The body weights of mice given single doses of 10 mug SPM remained much the same, while significant weight losses occurred in both the SPM 20 mug and 40 mug dosed groups. There was a significant prolongation of pentobarbital induced sleep 6 days after the injection of high doses of SPD or SPM. Similar prolongation of sleeping time was also evident 30 minutes after the injection of SPM. A maximal hypothermic response with a fall by about 1 degree C was observed immediately following injection of 80 mug of SPD and 24 hours after the injection of 40 mug SPM, respectively.