Somatostatin administration alters taste preferences in the rat.

The effects of long-term and relatively constant concentrations of somatostatin (SRIF) were tested in rats to investigate its influence on taste preferences, fluid intake, and taste bud topography of the tongue. In SRIF-treated rats, intake of 3 x 10(-2) M NaCl and 6 x 10(-2) M sucrose solution decreased, whereas that of 3 x 10(-5) M quinine-HCl and 10(-3) M HCl (pH = 3) solutions increased significantly; distilled water intake and total fluid consumption remained almost unchanged. The light/dark cycle of consumption of NaCl solution was modified in a dose-dependent manner, but that of dwater, total fluids, and other solutions was not. Histologic exam by light microscopy showed that taste bud distribution on the tongue appeared to be altered, but the results only approached statistical significance. Given that it is possible to remove virtually all taste buds in the oral cavity and have only modest effects on preferences and aversion, it seems very unlikely that the small changes in taste bud distribution are related to the intake of sapid solutions. Since SRIF treatment influenced all sapid stimuli, it seems more likely that the changes are based on a blunted responsiveness in the gustatory system as a whole.