Table 1.

Potencies for Methanocarba Analogues and the Corresponding Naturally Occurring Nucleotides in the Activation of Phospholipase C

Northern
			a, methanocarba	b, ribose
compd	analogue	subtype	EC50 (µM) of (N)-methanocarba analoguea	EC50 (µM) of corresponding ribose nucleotidea,b
3a	ATP	tP2Y1	0.014 ± 0.003	2.8 ± 0.7
		hP2Y1	0.052 ± 0.022	1.5 ± 0.2
		hP2Y2	0.091 ± 0.005	0.085 ± 0.012
		hP2Y4	32% at 10 µM	c
		hP2Y11	34.5 ± 4.7% at 10 µM	17.25 ± 2.80
4a	AMP	tP2Y1	NEd	NE
5a	UTP	hP2Y2	0.0159 ± 0.007	0.008 ± 0.002
		hP2Y4	0.085 ± 0.005	0.049 ± 0.010
		hP2Y6	NE
		hP2Y11	NE
6a	UDP	hP2Y6	NE	0.015 ± 0.004
7a	UMP	hP2Y6	NE	NE
Southern
compd	analogue	subtype	EC50 (µM) of (S)-methanocarba analoguea	EC50 (µM) of corresponding ribose nucleotidea,b
8a	ATP	tP2Y1	3.5 ± 0.66	2.8 ± 0.7
		hP2Y1	7.2 ± 1.0	1.5 ± 0.2
		hP2Y2	3.7 ± 0.5	0.085 ± 0.012
		hP2Y4	NE	c
		hP2Y11	NE	17.25 ± 2.80
9a	AMP	tP2Y1	NE	NE

^aAverage ± SEM.

^bValues from refs 32, 33, 38, and 39.

^cAntagonist effect.³⁷

^dNE means “no effect at 100 µM”.