Effect of varying dose and administration of streptozotocin on blood sugar in male CD1 mice.

Streptozotocin (STZ) is used to induce experimental diabetes in rodents. There is however, controversy as to whether STZ induced diabetes models type 1 or 2 diabetes. We show that the grade of STZ-induced hyperglycemia in male CD1 mice is dependent on STZ dose. A single injection of high dose (130 or 150 mg/Kg body weight) or multiple injections (2, 3, 4 or 5) of low dose (40 mg/Kg body weight) STZ was administered intraperitonealy in non-fasted mice. Blood glucose and body weight were measured over 21 days for high dose and 21 and 28 days for low dose administration. On day three, high dose treatment produced hyperglycemia and body weight loss in comparison to mice without STZ, however unstable hyperglycemias and several deaths were observed during treatment. Hyperglycemia and body weight loss were seen with three or more injections of STZ at 21 days, whereas 4 and 5 injections produced severe hyperglycemia but not death. Mild hyperglycemia (250-450 mg/dL) was seen after 28 days following three injections of STZ. Therefore we concluded that a high dose STZ produces severe hyperglycemia in mice similar to a type 1 diabetic, and three successive administrations of STZ induces mild hyperglycemia in mice similar to type 2 diabetics.

Adipsic, but not anorectic, effect of fluprazine hydrochloride in rats.

The present experiment explored the anorectic and adipsic effects of fluprazine hydrochloride, a phenylpiperazine compound. Thirty-eight albino rats were randomly assigned either to a control saline group (six rats) or to groups (eight subjects each) receiving an IP dose of fluprazine in saline (1.25, 2.5, 5 or 10 mg/kg). No anorectic effect of the drug doses was observed 30, 60, 90, 120, 180 and 240 min, and 24 h after drug injection. However, water drinking was significantly decreased 30 min after drug administration, with 5 and 10 mg/kg, compared to saline.

Behavioral and biochemical correlates of chronic administration of quipazine.

In Experiment 1 groups of rats received single injections of 1, 3, 10, 20 or 40 mg/kg quipazine, and their total 24-hr food and water intake after a 24-hr deprivation period was recorded; there was a dose-related reduction of both food and water intake. In Experiment 2 a group of 15 rats received 5 mg/kg/day, SC quipazine during 29 days, and a control group received saline injections. During treatment, all animals were exposed to a 24-hr food and water deprivation schedule, alternated with 24 hr of free access. Food and water consumption was measured 2 and 24 hr after drug injection; regional 5-HT concentrations were determined at 1 and 13 treatment days by fluorometric assay. Beginning the first treatment day, food and water intake decreased, but by the 13th day the quipazine group had returned to normal ingestion levels. 5-HT concentrations were increased in cerebellum and cortex in acute conditions, but after 13 days they had decreased in cerebellar samples. In Experiment 3 we found that the effects of quipazine on food and water ingestion were recovered after 14 days of discontinuing chronic drug administration.