Table 2

Hypothalamic stimulators of food intake and their effect on body weight regulation

	Amino Acid Length	Site of Production	Site of Action	Effect on Body Weight
	Amino Acid Length	Site of Production	Site of Action	Administration	Antagonist	Overexpression	Knockout
NPY	36	ARC	PVN, PFH	↑	↓	→	→
β-endorphin	31	ARC	PVN, VMH^2-a	→	↓	?	↑
Galanin	29–30	PVN	PVN	→	→	?	→
MCH	19	LH	PVN, LH^2-b	→	?	?	↓
Orexin A and B	33 and 28	LH	LH, PVN, PFH	↑	?	↓	↓
Agouti-related protein	50	ARC	PVN	↑	↓	↑	?
Norepinephrine (α₂-receptor)	—	Brainstem	PVN	↑	↓	?	→ (Dopamine β-hydroxylase)

PFH, perifornical hypothalamus; ↑, increase; ↓, decrease; →, no change; ?, not reported.
↵2-a Response to injection is delayed (Baile et al., 1986).
↵2-b Decrease in food intake is reported (Presse et al., 1996).