TABLE 1.

NITRITE CONCENTRATIONS IN BALF AND AMs FROM RATS AND MICE WITH PCP^*

Sample	Animal	Normal	Suppressed†	4 Weeks of PCP	7 Weeks of PCP	IFN-γ/Eschrichia coli‡	Normal-Pc§
BALF	Rat	3.2 ± 0.2	3.4 ± 0.6	NA	2.1 ± 0.3*	NA	9.6 ± 1.3#
	Mouse	2.3 ± 0.4	2.2 ± 0.2	1.3 ± 0.1¶	1.0 ± 0.1*	NA	NA
AMs	Rat	4.2 ± 0.3	4.5 ± 0.4	NA	0.8 ± 0.1*	1.0 ± 0.1¶	15.6 ± 1.2#
	Mouse	4.8 ± 0.4	4.3 ± 0.3	2.0 ± 0.2¶	1.7 ± 0.2*	2.1 ± 0.3¶	NA

Definition of abbreviations: AMs, alveolar macrophages; BALF, bronchoalveolar lavage fluid; NA, not assessed; Pc, Pneumocystis; PCP, Pneumocystis pneumonia. All values are mean ±SD.

^*BALF and AM lysates were treated with nitrate reductase to convert nitrates to nitrites before the determination of nitrite concentrations. Nitrite concentrations in the first 5 ml rat BALF or the first 1 ml mouse BALF are expressed in μM, and those in AMs (1 × 10⁶ from rats, and 5 × 10⁵ from mice) are expressed in μM relative to 1 mg of protein in cell lysates.

^†Rats were immunosuppressed with dexamethasone, and mice were immunosuppressed with anti-CD4 antibody.

^‡Preincubated with 10 ng/ml IFN-γ and 5 × 10⁶ Escherichia coli for 1 hour before assay.

^§Normal rats challenged with P. carinii.

^¶P < 0.05 versus immunosuppressed control samples.

^#P < 0.05 versus normal control samples.