Table 1.

Contractile effect of PGF_2α (in the absence or presence of 300 μM L-NAME) in extrapulmonary and intrapulmonary arteries from normoxic and hypoxic mice

	Contraction to PGF2α
	pD2	Emax (mN mm−1)
Extrapulmonary arteries
Normoxia (int ∅: 0.79–0.85 mm)
Alone	5.20±0.05	1.19±0.06
+L-NAME	5.44±0.04*	1.23±0.04
Hypoxia (int ∅: 1.04–1.10 mm)
Alone	5.73±0.11+++	1.82±0.10+++
+L-NAME	5.82±0.09	1.74±0.13
Intrapulmonary arteries
Normoxia (int ∅: 0.53–0.57 mm)
Alone	5.10±0.09	0.90±0.05
+L-NAME	5.36±0.09**	0.98±0.06
Hypoxia (int ∅: 0.69–0.73 mm)
Alone	5.54±0.05++	1.69±0.09++
+L-NAME	5.61±0.13	1.63±0.05

Arteries from normoxic and hypoxic mice were studied under a resting tension corresponding to an equivalent transmural pressure of 15 or 30 mmHg, respectively (see Methods). Corresponding internal diameters (int ∅) of arterial segments are indicated.

^*P<0.05,

^**P<0.01: significant difference compared to respective controls (without L-NAME; paired Student's t-test).

⁺⁺P<0.01,

⁺⁺⁺P<0.001: significant difference compared to normoxia (unpaired Student's t-test). n=6–9.