Effect of palmitoleic acid on insulin resistance in KK-Ay mice. Animals were orally administered vehicle (control), 300 mg/kg of palmitic acid, or 300 mg/kg palmitoleic acid on a daily basis for 4 weeks. (A) Plasma glucose levels in an insulin tolerance test. The insulin tolerance test was carried out on day 22 of the 4-week experiment. Animals were deprived of food for 5 h before administration of the insulin. Blood samples were collected immediately before the insulin injection (0 min) and 30, 60, and 120 min later. Values are means ± SE, n = 10. p < 0.1 and *p < 0.05 compared with the control group. (B) Plasma insulin levels. Blood samples were collected at the end of 4-week experiment after over-night fasting. Means in a row with superscripts without common letter are different, p < 0.05. C16:0, palmitic acid; C16:1, palmitoleic acid.