Table 1.

Binding properties and functional activities of select CRF receptor ligands

Peptide	CRF-R1		CRF-R2
	Avg. Ki, nM (binding)	Avg. EC50, nM (cAMP)	Avg. Ki, nM (binding)	Avg. EC50, nM (cAMP)
Ucn II (mouse)	>100	>100	0.66 (0.13–3.3)	0.14 (0.03–0.52)
URP (human)	>100	>100	0.50 (0.22–1.16)	0.42 (0.16–1.1)
Ucn (rat)	0.32 (0.14–0.77)	0.29 (0.12–0.70)	0.62 (0.14–2.8)	0.17 (0.043–0.68)

The values were determined from three to six independent experiments using stably transfected Chinese hamster ovary cells or their membranes for each test peptide. EC₅₀ and K_i values were determined by using prism software. Their log₁₀ values were averaged (γ). The average EC₅₀ or K_i was taken to be 10^γ. The standard deviation of the log₁₀ values was calculated (σ). The ranges given were taken to be [(10^γ)10^σ or 10^γ/10^σ].