Effect of oral nicotine administration on insulin secretion and insulin resistance in Zucker fatty rats.

To investigate the effect of nicotine on insulin secretion and insulin resistance in vivo, we studied male Zucker fatty rats administered nicotine orally. Eight-week-old male Zucker fatty rats were divided into two groups. The (N) group was administered nicotine tartrate (4.6mg/kg/day) for 8weeks. The control group (C) was pair-fed rats. Blood glucose levels in N group were significantly lower than in C group before and 120min after oral glucose load (2g/Kg). TNF-alpha, FFA and leptin levels in portal and peripheral blood were similar in both groups. TNF-alpha levels in both the visceral fat and abdominal subcutaneous fat in the N group were significantly lower than those of the C group. Oral nicotine administration may, therefore, reduce insulin resistance in obese diabetic rats, possibly through decreased production of TNF-alpha in fat tissues.