TABLE 2

Affinities of AVP determined by saturation experiments (K_d) or by competition experiments (K_i) with ¹²⁵I-HO-LVA as radiotracer on membranes of COS-7 cells expressing vasopressin V1a receptor

	Labeled Ligand
	[³H]AVP (K_d)	¹²⁵I-HO-LVA (K_{i AVP})
	nM
Receptor
Human W.T. V_1a	0.7 ± 0.2	3.4 ± 1.1
Human Q185A V_1a	46 ± 7^a	810 ± 148^a
Rat K128A V_1a	1.2^b	266 ± 108^c
Rat Q131A V_1a	11.4^b	168 ± 87^c

↵ a Values from Cotte et al.(2000).
↵ b Values from Barberis et al. (1993).
↵ c Values from Mouillac et al. (1995a).