K. Rahmouni et Wg. Haynes, Leptin signaling pathways in the central nervous system: interactions between neuropeptide Y and melanocortins, BIOESSAYS, 23(12), 2001, pp. 1095-1099
No other hormone has drawn more attention than leptin in recent studies on
the control of appetite, body weight and obesity. This hormone is produced
by adipose tissue and enters the brain via a saturable specific transport m
echanism. Leptin acts in the hypothalamus to modulate food intake and heat
production as well as several other neuroendocrine pathways. The mechanisms
through which leptin exerts its central nervous effects are now better und
erstood. Proopiomelanocortin- and neuropeptide Y-containing neurons in the
hypothalamus have emerged as potent candidate mediators of leptin action. T
hese two neuropeptides have been shown to exert opposing effects using diff
erent pathways, Recently, Cowley et al. (1) described a new circuit in the
regulation of neuronal activity by leptin with an Interaction between these
two pathways. These data add complexity to the mechanisms by which leptin
achieves its effects in the central nervous system, but they also offer pot
ential mechanisms to explain the phenomenon of leptin resistance observed I
n obesity. (C) 2001 John Wiley & Sons, Inc.