Table 5.

Physiological status of ghrelin, CCK, GLP-1, and PYY(3–36) in the endocrine control of eating, GI motility, and meal-related glycemic control in healthy humans

	Eating PD/A	GI Motility* PD/A	Meal-Related Glycemic Control PD/A
Ghrelin	?/?	?/?	?/?
CCK	YES/YES	Yes/Yes†	YES/No
GLP-1	YES/No‡	Yes/Yes	YES/YES
PYY(3–36)	No/?	Yes/?	?/?

Experimental support for the two cardinal criteria of physiological endocrine function, i.e., the “physiological-dose” criterion (PD) and “antagonism” criterion (A), is rated as convincing (YES), partial (Yes), negative (No), or unknown (?) for each hormone and function. See text for details and references.

^*GI motility refers to gastric emptying and small-intestinal motor function.

^†Cholecystokinin (CCK) antagonism slowed gastric emptying of liquid food, but not solid food.

^‡In two studies (489, 714), premeal administration of the GLP-1 receptor antagonist exendin-9 failed to increase eating, although in one study (714) subjective ratings of appetite increased.