Table 1.

Comparison of the Hill coefficient (h) of vanilloid or analog dose responses of TRPV1 channels.

Ligand	Ion channel source	Vh, mV	ha	Ref
resiniferatoxin	rTRPV1	−60	1.95	[2]
capsaicin	rTRPV1	−60	2.08	[2]
capsaicin	mTRPV1	+80	1.82	[5]
capsaicin	Y512F/mTRPV1	+80	1.31	[5]
capsaicin	S513A/mTRPV1	+80	1.23	[5]
capsaicin	F544A/mTRPV1	+80	1.13	[5]
capsaicin	R558L/mTRPV1	+80	1.19	[5]
capsaicin	I662A/mTRPV1	+80	0.92	[5]
capsaicin	A666L/mTRPV1	+80	1.20	[5]
capsaicin	T671V/mTRPV1	+80	0.98	[5]
capsaicin	T671S/mTRPV1	+80	1.28	[5]
capsaicin	CFTR	±100	1.92	[31]
peperine	mTRPV1	0	2.20	[24]
peperine	T551V/mTRPV1	0	1.3	[24]
6-Shogaol	mTRPV1	+80	1.10	[25]
6-Gingerol	mTRPV1	+80	1.70	[25]
6-Zingerone	mTRPV1	+80	0.90	[25]
capsazerpine	mTRPV1	+80	1.38	[5]
Curcumin	mTRPV1	−60	0.88	[28]
Curcumin	mTRPV1	−60	0.89	[30]
Naicin	hTRPV1	+80	2.87	[26]
Histamine	mTRPV1		3.82	[36]

^ah values were based on the non-linear curve fitting of the Hill equation, I=I_max*[L]^h/(K_1/2^h +[L]^h)_, where, I_max is the maximum effect; L is the ligand; K_1/2 is the ligand concentration that produces a 50% maximal response and h is the Hill coefficient.