Table 1.

Studies measuring the affinity, potency and efficacy of anandamide at recombinant TRPV1 receptors

Cell line	Affinity (Ki)	Measured response	pH	Potency (pEC50)	Efficacy (Emax) (%)a	Reference
HEK 293(rat)		Inward current	7.4	5.31±0.06	∼30–50	Zygmunt et al. (1999)
		[Ca2+]i (FLIPR)	7.4	5.73±0.04	100	Ralevic et al. (2001)
			6.4	5.76±0.04	—	Ralevic et al. (2001)
		[Ca2+]i (FLIPR)	—	5.85±0.01	100	Jerman et al. (2002)
		[Ca2+]i (Fura-2)	—	5.85±0.12 (22°C)	63	Sprague et al. (2001)
				5.15±0.04 (37°C)	72	Sprague et al. (2001)
				<4 (50°C)	120	Sprague et al. (2001)
HEK 293 (human)		[Ca2+]i (FLIPR)	7.4	5.94±0.06	100	Smart et al. (2000)
			6.4	5.76±0.04	100	Smart et al. (2000)
			7.4	5.60±0.10	100	Ralevic et al. (2001)
			7.4	6.66 (with LEA)b	—	Smart et al. (2000)
			7.4	5.74 (no LEA)	—	Smart et al. (2002)
	—	[Ca2+]i (Fluro-3 imaging)	7.4	6.20	100	De Petrocellis et al. (2001a)
	5.40 (with PEA)		7.4	6.66 (with PEA)c	—	De Petrocellis et al. (2001b)
	4.72 (no PEA)			6.36 (no PEA)	—	De Petrocellis et al. (2001b)
CHO (rat)	5.78±0.06 (with PMSF)	[Ca2+]i ([45Ca2+] uptake)	7.4	5.80±0.04 (with PMSF)d	100	Ross et al. (2001b)
	<5 (no PMSF)		7.4	<5 (no PMSF)	—	Ross et al. (2001b)
CHO (guinea-pig)		[Ca2+]i	7.5	5.01	∼22	Savidge et al. (2002)
NIH 3T3 (rat)		[Ca2+]i ([45Ca2+] uptake)	5.5	4.85	—	Olah et al. (2001)
			6.0	4.60	—	Olah et al. (2001)
			6.5	4.20	—	Olah et al. (2001)

^aRelative to that of capsaicin (100%).

^bLauroylethanolamide (LEA) is an N-acylethanolamide.

^cPalmitoylethanolamide (PEA) is an N-acylethanolamide.

^dPhenylmethylsulphonyl fluoride (PMSF) is an inhibitor of FAAH.