Table 3. K_i values and relative affinities of GHRH antagonists to membrane receptors on rat anterior pituitary cells.

Antagonist
No	Code no.	Ki*, nM	Relative affinity†
Standard antagonist		4.88	1
1	JV-1-62	0.057	86
2	JV-1-63	0.062	79
5	JV-1-88	0.070	70
6	JV-1-91	0.091	54
7	JV-1-93	0.072	68
8	JV-1-87	0.33	15
9	JV-1-86	0.14	35
13	JV-1-65	0.089	55
14	JV-1-67	0.090	54
16	MZ-J-7-72	0.074	66
17	MZ-J-7-88	0.069	71
18	MZ-J-7-89	0.081	60
19	MZ-J-7-90	0.071	69
20	MZ-J-7-74	0.070	70
21	MZ-J-7-78	0.073	67
22	JV-1-36‡	0.079	62
23	JV-1-38‡	0.085	57

^*Dissociation constant of the inhibitor-receptor complex. Values were calculated from duplicate or triplicate determinations

^†Expressed relative to [Ac-Tyr¹, d-Arg²] hGHRH(1-29)NH₂ (standard antagonist) = 1.0

^‡Reference compounds