PHILIPPE ZIZZARITransgenic mice with an overactive form of the receptor for ghrelin—often dubbed the “hunger hormone”—do not have the increased appetites one might expect, yet still gain weight, according to a paper published yesterday (April 19) in Science Signaling. The results suggest that the long-held view of ghrelin as a regulator of food intake may not be entirely accurate. But not everyone is convinced.
“It’s an intellectually intriguing finding,” said Yale School of Medicine’s Tamas Horvath who was not involved in the study. “Am I 100 percent convinced that this proves that ghrelin has no effect on feeding? No. But I think that [the authors] come up with a provocative set of data and I think . . . it’s going to initiate more thorough studies on this important question,” he added.
Ghrelin and its only known receptor, the growth hormone secretagogue receptor (GHSR), have been implicated in, among other things, food intake, growth hormone secretion, and the production of fatty tissue (adipogenesis). Injections of ghrelin, for example, have been shown to increase food intake and adipogenesis in rodents. In humans, levels of ghrelin in the blood have been ...
