Abstract: AIM: To study the effect of the change of paw withdrawal thermal latency (PWTL) and paw withdrawal mechanical threshold (PWMT) in high fat-glucose-salt diet-fed rats. METHODS: Thirty five-week-old male Sprague-Dawley rats weighing (100±5)g were divided into two groups: Group A(n=20)(high fat-glucose-salt diet-fed) and Group B, the control group (n=10). Food and water available to both groups were not limited. FBG (fasting blood glucose), FINS (the fasting insulin), PWTL, PWMT, blood pressure and the weight were measured at the 1^st, 10^th, 20^th, 30^th, 40^th, 50^th, 60^th, 70^th, 120^th day. RESULTS: (1)No change of FBG were found in the two groups. (2) Group A were significantly high in FINS after 20 days feeding, while that of the group B didn't change. The difference became increasingly remarkable on the 20^th, 30^th, 40^th, 50^th, 60^th, 70^th, and 120^th day. (3)after 70 days feeding, PWTL of group A (P<0.05) obviously decreased, whereas that of group B didn't. (4)PWMT of group A decreased after 60 days feeding (P<0.05), while that of group B didn't. (5)The blood pressure of group A was noticeably higher than that of group B when measured on the 20^th, 30^th, 40^th, 50^th, 60^th, 70^th, 120^th day. (6)The weight of both groups increased until the 70th day when significant differences were observed (P<0.05). CONCLUSION: High fat-glucose-salt diet can induce high blood pressure, hyperinsulinemic, insulin resistance (on the 20^th day), thermal hyperalgesia (on the 70^th day) and mechanical hyperalgesia (on the 60^th day). But high blood pressure, hyperinsulinemic, insulin resistance didn't appear at the same time with hyperalgesia.

Key words: Pain threshold, Paw withdrawal thermal latency, Paw withdrawal mechanical threshold, Insulin resistance