Table 1. Product/substrate ratios and physiological reaction quotients in mouse tissues.

	NMNAT reaction (K eq∼1)				NADS reaction (K eq>106)
	[NAD]/[NMN]	[NaAD]/[NaMN]	[PPi]/[ATP]	Physiological reaction quotienta	[NAD]/[NaAD]	[AMP][PPi]/[ATP]	[Glu]/[Gln]	Physiological reaction quotient
skeletal muscle	78	62	0.03•10−3	0.002	11	0.005	0.6	0.03
lung	38	74	0.01•10−3	0.001	5,9	0.003	2.5	0.04
kidney	23	16b	0.39•10−3	0.009	∼1000	0.39	15	∼5800
brain	49	100b	1.29•10−3	0.063	∼1000	1.64	2.0	∼3200
spleen	45	36	0.12•10−3	0.005	24	0.10	26	60
small intestine	31	22	0.23•10−3	0.007	32	0.18	4.4	26
heart	38	20	0.16•10−3	0.006	99	0.19	0.7	13
liver	54	42	0.12•10−3	0.006	68	0.18	0.3	4
blood	4	2b	0.01•10−3	0.00002	∼50	0.0002	1.5	∼0.01

^aValues are calculated for the “amidated” reaction catalyzed by NMNAT; the corresponding values for the “deamidated” reaction are of the same magnitude.

^bNaMN and/or NaAD determined values are very close to the assay detection limit.