Tissue angiotensin-converting enzyme (ACE) was measured in 60 patients with psoriasis and in 20 healthy individuals. According to clinical forms of psoriasis, 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 tissue ACE activity was determined before and after therapy, by the spectrophotometric method using hippuryl-l-histidyl-l-leucine as a substrate. The enzyme activity is expressed in units: 1 U corresponds to 1 nmol of hippuric acid released by hydrolysis of hippuryl-l-histidyl-l-leucine per minute and 50 mg of the tissue. Before therapy, tissue ACE activity was significantly increased in patients with psoriasis (4,14+/-0,34; X+/-SEM) in comparison to healthy individuals (1,86+/-0,16). The greatest increase in tissue ACE activity was observed in patients with erythrodermic psoriasis (4,72+/-0,65), followed by those with multiple disseminated lesions (4,24+/-0,63) and solitary psoriatic lesions (3,47+/-0,48). After therapy, serum ACE activity was significantly decreased in all clinical forms of the disease. Determination of tissue ACE activity might be a good non-specific parameter for assessment therapeutic effects.

Serum and tissue (kidney's) angiotensin-converting enzyme (ACE) activity has been examined in Wistar rats (10 males and 10 females), seven days after unilateral nephrectomy. Renal hypertrophy was determined by measurement of kidney absolute mass. Serum and tissue ACE activity was determined by spectrophotometric method using hippuryl-l-histidyl-l-leucine (Hip-His-Leu) as a substrate. The ACE serum activity was expressed in units that correspond to 1 nmol of hippuric acid released by enzymatic hydrolysis of Hip-His-Leu substrate per minute/ml serum. The ACE tissue activity was expressed in units that correspond to 1 nmol of hippuric acid released by enzymatic hydrolysis of Hip-His-Leu substrate per minute/mg protein or mg kidney's tissue. The ACE serum activity significantly increased (p<0,05) seven days after unilateral nephrectomy. The ACE tissue activity, expressed in units that corresponds to 1 nmol of hippuric acid released by hydrolysis of Hip-His-Leu substrate per minute/mg protein, was higher seven days after unilateral nephrectomy then in kidney control, but the difference was not significant compared to the values determined in kidney control. The ACE tissue activity, expressed in units that correspond to 1 nmol of hippuric acid released by hydrolysis of Hip-His-Leu substrate per minute/mg tissue, was increased seven days after unilateral nephrectomy, which is statistically significant compared to the activity of the same enzyme in kidney control (p<0,01). The results indicate that ACE, probably has an important role in development of adaptive compensatory mechanisms after unilateral nephrectomy.

Nitric oxide (NO) level in serum and renal tissue has been examined in 15 male Wistar rats, body weight 200-250 g, 7 days after unilateral nephrectomy. All rats were ether-anaesthetized and the kidneys were removed by dorsolateral approach. NO concentration in serum and renal tissue was determined by classic colorimetric Griess reaction. Conversion of NO(3)(2-) into NO(2)(2-) was done with elementary zinc. Results have shown that NO concentration in renal tissue is statistically higher in rats 7 days after unilateral nephrectomy then in control renal tissue before compensatory kidney growth (p<0,02). There is no difference between NO concentration in serum before unilateral nephrectomy and 7 days after nephrectomy. These findings suggest that NO may play an important role in mediating the hemodynamic changes associated with reduced renal mass.

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.

Angiotensin converting enzyme (ACE) plays an important role in blood pressure regulation not only in the state of rest, but also during physical exercise. The aim of this study was to estimate the serum ACE activity in response to acute dynamic exercise. The study involved a group of young, healthy, male volunteers (average 22 years of age). Exercise testing was carried out on ergometer bicycle according to the protocol of individually adjusted continuous, constant workload (3 W/kg). The activity of ACE in serum was measured in venous blood, in the period of rest, in 4th, 8th and 12th minute of exercise and 1st, 3rd and 6th minute of recovery by spectrophotometric method. Marked inter-individual differences in basal serum ACE activity were determined (range 8, 31-63, 72 U/L). Serum ACE activity did not significantly vary during exercise and in the period of recovery. Systolic blood pressure changed during exercise compared to values during rest period in accordance with the applied type of dynamical exercise. Diastolic blood pressure did not vary considerably during exercise. Statistically significant correlation between mean arterial blood pressure and ACE activity in the serum was not found. The lack of increase of ACE activity in the serum, in spite of changes in blood pressure values, most likely shows the presence of alternative ACE independent pathway involved in the production of vasoactive substances that have important role in the regulation of cardiovascular system response to acute dynamic exercise.

The qualitative and quantitative study of renal cortical structures was performed seven days after unilateral nephrectomy. Adult Wistar rats (10 male and 10 female) were ether-anaesthetized and the kidneys were removed by dorsolateral approach. Renal hypertrophy was determined by measurement of kidney dry mass. The samples of renal tissue were embedded in paraffin, sectioned at 6 microns and stained by azan and haematoxylineosin methods. The volume densities of renal corpuscles, the epithelium of tubules, luminal space of tubules and cortical interstitial structures were calculated using Weibel's multipurpose test system M 42. The qualitative analysis was performed to determine possible structural sex differences of cortical parenchyma during compensatory hypertrophy. There was no significant difference in volume densities of renal corpuscles and distal tubules between control and hypertrophic kidney. The volume density of the epithelium of proximal tubules and interstitial blood vessels were statistically significant increased in hypertrophic kidney compared to the values determined in control kidney. The volume density of luminal space of proximal tubules and interstitial tissues were statistically significant decreased in hypertrophy compared to control kidney. The data from present studies shows that the increase in epithelial volume of proximal tubules and interstitial blood vessels volume have the primary role in compensatory kidney enlargement after unilateral nephrectomy, while renal corpuscles do not participate significantly.

OBJECTIVE Previous studies have pointed to the changes of serum angiotensin-converting enzyme (SACE) values in patients with liver disease and cancer located in different sites. The aim of this study was to determine the changes in SACE values in patients with hepatocellular carcinoma (HCC) and liver cirrhosis. METHODS The study comprised 30 patients with HCC (22 men and eight women) of average age 48.6 +/- 9.0 years and 30 patients with liver cirrhosis (21 men, nine women) of average age 49.1 +/- 9.5 years. The control group consisted of 30 healthy volunteers with matching anthropometric characteristics. SACE activity was determined by a spectrophotometric method using synthetic hippuryl-glycyl-glycine as substrate. RESULTS The mean SACE value was considerably lower in patients with HCC, 22.8 U/ml (95% CI, 22.5-23.9), both those in whom HCC developed in cirrhotic liver (n = 23), 23.7 (22.9-24.5) as well as those with HCC without cirrhosis (n = 7), 21.8 (21.0-22.6), with regard to patients with liver cirrhosis, 37.2 (36.6-37.8) (P < 0.001). There was also a statistically significant difference between healthy, 29.9 (29.4-30.3), and both groups of HCC patients (P < 0.001). No significant differences could be found between the group of HCC patients with and without liver cirrhosis (P < 0.05). In patients with liver cirrhosis SACE value was increased in accordance with the severity of the disease expressed by Child's classification; however, at each stage SACE values were considerably lower in patients with HCC in cirrhotic liver (Child A, 35.8 vs 22.1; Child B, 38.7 vs 24.2; Child C, 40.0 vs 28.3) (P < 0.001). Alfa-fetoprotein (AFP) values did not correlate with the SACE activity. The SACE value was also significantly decreased in patients with HCC whose AFP were not altered. CONCLUSION The study has shown that SACE values are low in patients with advanced HCC. It may be helpful in detecting HCC in patients with cirrhosis, where it can be difficult to differentiate between small HCC tumours and regeneration nodules.