Novolin 70 30 insulin

Four weeks to 5 weeks old Sprague Dawley rats (n=9–15 per group, 100 g, male and female, Charles River Laboratories, Wilmington, Massachusetts, USA) were treated with an intraperitoneal (IP) injection of streptozotocin (STZ, Sigma-Aldrich, St. Louis, Missouri, USA) 165 mg/kg to induce diabetes. NG control rats received an IP injection of STZ vehicle (citric acid, Sigma-Aldrich, St. Louis, Missouri, USA). The rats’ drinking water was replaced with water containing 10% dextrose (Fisher Scientific, Santa Clara, California, USA) for 24 hours after STZ treatment to prevent hypoglycemia. Urine glucose and acetoacetate were measured daily (Multistix urinalysis strips, BAYER, Fisher Scientific, Santa Clara, California, USA). Beginning 24 hours after STZ injection, rats were treated with subcutaneous (SC) insulin (Novolin 70:30 insulin (Novo Nordisk, Princeton, New Jersey, USA), 1 unit in the morning and 2 units in the evening). STZ-treated rats in the HG control group continued to receive SC insulin injections twice daily for the duration of the experiments. In the DKA groups, SC insulin injections were given for 6 days after STZ, after which they were withheld to induce DKA.

Sprague Dawley rats 4–5 weeks old (n=6–7 per group, 100 g, male and female, Charles River Laboratories, Wilmington, Massachusetts, USA) were used for these experiments. Rats were treated with streptozotocin (STZ; Sigma-Aldrich, St. Louis, Missouri, USA) 165 mg/kg via intraperitoneal injection to induce diabetes. Normoglycemic (NG) controls received an intraperitoneal injection of STZ vehicle (citric acid, Sigma-Aldrich). Rats were allowed unlimited access to water containing 10% dextrose (Fisher Scientific, Santa Clara, California, USA) in the first 24 hours after STZ injection to prevent hypoglycemia. Urine glucose and acetoacetate were measured daily using Multistix urinalysis strips (Bayer, Fisher Scientific). Rats treated with STZ were administered insulin 24 hours after STZ injection (1 unit of Novolin 70:30 insulin (Novo Nordisk, Princeton, New Jersey, USA) administered subcutaneously in the morning and two units in the evening). STZ-treated rats in the hyperglycemic (HG) control group continued to receive subcutaneous insulin injections for the duration of the experiments. Rats in the DKA groups received insulin injections for 6 days after STZ administration, at which time injections were held to induce DKA.