TY - JOUR
T1 - Dysregulation of leptin in response to fasting in insulin-resistant Psammomys obesus (Israeli sand rats)
AU - Walder, Ken
AU - Lee, Scott
AU - Zimmet, Paul
AU - Collier, Greg R.
PY - 1998
Y1 - 1998
N2 - Leptin is thought to play a significant role in energy balance as an afferent signal to the hypothalamus that reflects body fat content. In addition, leptin may also act as an acute sensor of energy balance independent of body fat mass, since ob gene expression and plasma leptin concentrations are decreased in lean animals and humans in response to short- term caloric deprivation. However, in obese animals and humans, the acute response of leptin to fasting is less clear. We investigated the effects of 8 24-hour fast on circulating plasma leptin concentrations in lean and obese Psammomys obesus (Israeli send rats). In the lean, insulin-sensitive group (n = 25) a 24-hour fast caused a 44% decrease in plasma leptin, whereas in the obese, insulin-resistant group (n = 24) plasma leptin increased by 18% after fasting (P < .003). There was no difference between the two group regarding the effect of a 24-hour fast on body weight, blood glucose, or plasma insulin. Within the insulin-resistant group, there no difference in the response of leptin to fasting between hyperglycemic and normoglycemic animals. We conclude that there is a dysregulation of leptin in response to acute caloric deprivation in obese, insulin-resistant but not in lean, insulin-sensitive P obesus.
AB - Leptin is thought to play a significant role in energy balance as an afferent signal to the hypothalamus that reflects body fat content. In addition, leptin may also act as an acute sensor of energy balance independent of body fat mass, since ob gene expression and plasma leptin concentrations are decreased in lean animals and humans in response to short- term caloric deprivation. However, in obese animals and humans, the acute response of leptin to fasting is less clear. We investigated the effects of 8 24-hour fast on circulating plasma leptin concentrations in lean and obese Psammomys obesus (Israeli send rats). In the lean, insulin-sensitive group (n = 25) a 24-hour fast caused a 44% decrease in plasma leptin, whereas in the obese, insulin-resistant group (n = 24) plasma leptin increased by 18% after fasting (P < .003). There was no difference between the two group regarding the effect of a 24-hour fast on body weight, blood glucose, or plasma insulin. Within the insulin-resistant group, there no difference in the response of leptin to fasting between hyperglycemic and normoglycemic animals. We conclude that there is a dysregulation of leptin in response to acute caloric deprivation in obese, insulin-resistant but not in lean, insulin-sensitive P obesus.
UR - http://www.scopus.com/inward/record.url?scp=0031933818&partnerID=8YFLogxK
U2 - 10.1016/S0026-0495(98)90206-2
DO - 10.1016/S0026-0495(98)90206-2
M3 - Article
C2 - 9440491
AN - SCOPUS:0031933818
SN - 0026-0495
VL - 47
SP - 125
EP - 128
JO - Metabolism: Clinical and Experimental
JF - Metabolism: Clinical and Experimental
IS - 1
ER -