Table 1.

Modulation of cGMP levels in NANC relaxation

Treatment	cGMP, fmol/mg
	Wild type	HO-2Δ/Δ	nNOSΔ/Δ
Unstimulated
Control	817  ±  89.7	450  ±  49.2*	603  ±  51.7*
SnPP-IX 10−5 M	787  ±  56.3	472  ±  24.3	589  ±  47.6
L-NNA 10−4 M	840  ±  69.7	415  ±  32.9	615  ±  42.3
ODQ 10−5 M	553  ±  48.3	302  ±  21.8	438  ±  31.9
DMPP-stimulated
Control	1785  ±  165	602  ±  62.7*	931  ±  73.8*
SnPP-IX 10−5 M	1271  ±  88.5†	588  ±  43.9	326  ±  38.9†
L-NNA 10−4 M	1006  ±  69.6‡	198  ±  21.6‡	822  ±  66.7
ODQ 10−5 M	603  ±  57.8	389  ±  27.3	467  ±  32.1
CO 10−3 M	1960  ±  143	2100  ±  187	2050  ±  225
SNP 10−4 M	2197  ±  178	2267  ±  209	2003  ±  126

Ileal muscle strips were treated with DMPP (3 × 10⁻⁵ M) for 30 s and instantaneously frozen. cGMP content was determined by radioimmunassay as described in Materials and Methods. 

^*Significant difference between knockout and control values. P < 0.01, Student’s t test. 

^†Significant reduction by SnPP-IX, P < 0.01, Student’s t test. 

^‡Significant reduction by L-NNA, P < 0.01, Student’s t test.