TABLE 5.

Cytokine titers of PWF from vehicle- and IL-18-administered BALB/c mice treated with d- or l-NMMA 26 h after i.p. inoculation with 10⁴ PFU of HSV-1

In vivo treatment	PWF
	Antiviral activitya (mIFN-α IU/ml)	IFN-γb (101 pg/ml)
d-NMMAc + vehicled	13 ± 8e	<32 ± 45
l-NMMA + vehicle	37 ± 57	<29 ± 33
d-NMMA + IL-18	<1 ± 0	<6 ± 0
l-NMMA + IL-18	<1 ± 0	<6 ± 0

^aAntiviral activity was measured by using VSV and mouse L929 cells and is expressed as the mIFN-α titer. 

^bMeasured by ELISA. 

^cd- or l-NMMA was injected i.p. on days 3, 2, and 1 before infection and days 0 and 1 after infection. 

^dOn days 2 and 1 before infection and days 0 and 1 of infection, 1 μg of IL-18 was injected i.p. into each mouse (n = 5 per group), and the mice were sacrificed to prepare PWF 2 h after the final injection with the vehicle or IL-18 and 4 h after the final injection with d- or l-NMMA. 

^eMean ± standard deviation.