In order to study concentration of nitric oxide (NO) in the saliva of patients with Parkinson's disease (PD), we measured the concentration of its stable metabolite nitrite (NO(2)-) in the saliva of these patients and healthy subjects. We analyzed saliva flow rate and salivary NO concentrations in 16 subjects with Parkinson's disease and in 16 healthy subjects. Concentration of nitrite was determined by colorimetric method using Griess reaction. Saliva flow rate was significantly lower in patients with Parkinson's disease (0.2+/-0.03 mL/min; X+/-SEM) than in healthy subjects. Salivary NO(2)-concentration was significantly lower (5.02+/-0.64) than in healthy individuals (22.39+/-1.24, p<0.0001).

Serum and tissue angiotensin-converting enzyme (ACE) was measured in 20 patients with lichen planus before and after therapy, and in 20 healthy individuals. Serum and tissue ACE activity was determined by spectrophotometric method using hippuryl-l-histidyl-l-leucine as a substrate. The enzyme activity is expressed in the following units: 1 U corresponds to 1 nmol of hippuric acid released by hydrolysis of hippuryl-l-histidyl-l-leucine per minute and one liter of serum or 50 mg tissue. Before therapy, serum ACE activity was significantly increased in patients with lichen planus (35.9 +/- 2.33 U/L) in comparison to healthy individuals (28.16 +/- 1.7 U/L). Tissue ACE activity was increased in patients with lichen planus (2.24 +/- 0.41 U/50 mg) in comparison to healthy individuals (1.86 +/- 0.16 U/50 mg), but the difference was not significant. After therapy, serum and tissue ACE activity decreased and no significant difference in ACE activity was found. The determination of serum ACE activity may be a good non-specific parameter for the assessment of therapeutic effects.

Serum angiotensin-converting enzyme (ACE) was measured in 60 patients with psoriasis and in 16 healthy individuals. According to clinical forms ofpsoriasis, the patients were further divided into three groups: psoriasis with solitary lesions (n=20), psoriasis with multiple disseminated lesions (n=20) and erythrodermic psoriasis (n=20). The serum ACE activity was determined before and after therapy, by the spectrophotometric method using hippuryl-l-histidyl-l-leucine as a substrate. Before therapy, serum ACE activity was significantly increased in patients with psoriasis (47.20 +/- 2.06 U/L) in comparison to healthy individuals (28.33 +/- 1.32 U/L). The greatest increase in serum ACE activity was observed in patients with multiple disseminated lesions (78%), followed by those with solitary psoriatic lesions (76%) and erythrodermic psoriasis (31%). After therapy, serum ACE activity was significantly decreased in all clinical forms of the disease. In conclusion, the determination of serum ACE activity may be helpful in the diagnosis of psoriasis and one of the discriminators to assess the effects of used therapy.