Association of carotid intima-media thickness and cardiovascular risk factors in women pre- and post-bariatric surgery.

BACKGROUND: Obesity is associated with cardiovascular risk factors (CVRFs), such as hypertension, hypertriglyceridemia, and low levels of high-density cholesterol (HDL-C). In obese patients with a body mass index (BMI) of >or=40 kg/m2 or 35-40 kg/m2 associated with CVRFs, weight loss may be achieved more effectively by bariatric surgery on reducing several CVRFs. Carotid intima-media thickness (C-IMT) is an indicator of early atherosclerosis, and may be correlated with CVRFs. Our objective was to correlate C-IMT with CVRFs before (baseline data) and after surgery, and to observe whether weight loss is followed by a regression of C-IMT. METHODS: Eighteen women who had undergone bariatric surgery participated in this study. Assessments were carried out on the baseline date, and 3, 6, and 12 months after surgery. Some of the CVRFs analyzed were: total cholesterol (TC) levels, HDL-C, triglycerides to HDL-C ratio (TG/HDL-C) and fasting plasma glucose. C-IMT was measured by B-mode ultrasound. RESULTS: A positive correlation was found between C-IMT and age and triglyceride level (p=0.002 and p=0.02, respectively). Six months after surgery, we found a significant reduction in C-IMT (p<0.05), which was significantly correlated with TG level and systolic pressure (p<0.05). CONCLUSION: The weight loss achieved with bariatric surgery resulted in regression of C-IMT. This regression could be observed 6 months following surgery, with an additional benefit at 12 months. Also, this finding was correlated with a reduction in triglyceride levels and systolic blood pressure.

Endothelial function in normotensive and high-normal hypertensive subjects.

To evaluate the impact of a mild increment in blood pressure level on endothelial function, we evaluated 61 healthy volunteers (24 women, 37 men, and aged 35-50 years). All subjects underwent a blood chemistry panel to exclude any metabolic abnormalities and were submitted to a Doppler ultrasound of the brachial artery to assess endothelial function. We assessed the endothelial response to reactive hyperaemia and exogenous nitric oxide administration considering an increase in systolic blood pressure (SBP) at each 10-mm Hg interval. Our study population was divided as follows: SBP <115 mm Hg (SG1, n=13), SBP > or =115 mm Hg and <125 mm Hg (SG2, n=20), SBP > or = 125 mm Hg and <135 mm Hg (SG3, n=13) and SBP > or = 135 mm Hg and < 140 mm Hg (SG4, n=15). We found a significant difference in flow-mediated dilation among SG2, SG3 and SG4, 16.2+/-5.6, 13.4+/-5.2 and 11.5+/-3.6%, P<0.05, respectively). After nitrate administration, we observed a nonsignificant decrease in brachial artery dilation among groups, P=0.217. Our data showed in a healthy normotensive population, without any risk factor for atherosclerotic disease that small increases in SBP but not in diastolic blood pressure may impair endothelial function even in subjects considered as high-normal, meaning that this population deserves more attention than usually ascribed to intervene and prevent complications, as endothelial dysfunction may represent an early change in those who develop hypertension later in life.

Calcium channel blockers as inhibitors of angiotensin I-converting enzyme.

Using ion-exchange chromatography of dialyzed human urine from healthy and hypertensive patients, we detected two peaks of angiotensin I-converting enzyme (ACE) activity on hippuryl-His-Leu eluted at ionic strengths of 0.7 (F1 peak) and 1.25 (F2 peak) mS. These hydrolytic activities decreased gradually in the urine of patients submitted to isradipine treatment, F2 and F1 disappearing after 12 and 24 hours, respectively. By Western blot analysis, the urine fractions corresponding to both peaks from healthy and untreated patients presenting ACE activity and from treated patients (24 hours) without this activity were recognized by an ACE-specific antibody. These results indicated that ACE was present but inhibited in the urine of isradipine-treated patients. In vitro assays with ACE isolated from human urine and guinea pig plasma demonstrated that the enzyme is inhibited by isradipine and other commercially available calcium channel blockers, such as felodipine, nifedipine, and verapamil. A noncompetitive inhibition was observed with all calcium channel blockers studied. In conclusion, these results suggest that besides the primary effect on calcium channels, the more commonly used calcium channel blockers are also ACE inhibitors. The development of efficient calcium channel blockers with higher ACE inhibitory activity could result in interesting bifunctional antihypertensive drugs.

Purification and characterization of a neutral endopeptidase-like enzyme from human urine.

OBJECTIVE: The aims of this study were to purify and characterize a neutral endopeptidase-like enzyme (NEP-like) in human urine and propose a rapid, sensitive and specific assay for this enzyme using the fluorogenic substrate Abz-FDQ-EDDnp, where Abz = O-aminobenzoic acid and EDDnp = N-(2,4-dinitrophenyl)ethylenediamine. METHODS: Soluble urinary NEP was purified from human urine using a DEAE-cellulose Cellex D column and gel filtration on an AcA-44 column. NEP-like activity was assayed by its ability to hydrolyse bradykinin (BK) and the fluorogenic substrates Abz-BKQ-EDDnp and Abz-FDQ-EDDnp. The Km was determined using Abz-FDQ-EDDnp as a substrate. The hydrolysis products of BK and Abz-FDQ-EDDnp were analysed by high-performance liquid chromatography (HPLC). The mol. wt was estimated by polyacrylamide gel electrophoresis and the enzyme analysed by Western blot using the antibody obtained from purified recombinant NEP expressed in Pichia pastoris yeast. RESULTS: The NEP-like was purified from human urine until homogeneity and presented a mol. wt of 94000. The substrate Abz-FDQ-EDDnp was selectively hydrolysed at the F-D bond by NEP-like and by recombinant NEP. For this substrate, the NEP-like activity was maximal at pH 7.0, although a small peak of activity was observed at pH 8.0, and the determined Km was 14 microM. The enzymatic activity was inhibited by thiorphan and phosphoramidon. In Western blot analysis, NEP-like reacted strongly with a polyclonal antibody for NEP. CONCLUSION: A NEP-like enzyme was purified from human urine. Based on the mol. wt of the isolated NEP-like enzyme, it was concluded that this enzyme was produced in the kidney. In the kidney, this enzyme may cleave the kinins filtered through the glomerulus and also the kinins produced in the distal nephron. An internally quenched fluorogenic peptide, Abz-FDQ-EDDnp, was selectively hydrolysed by NEP-like and by recombinant NEP.

Contribution of vasopressin to orthostatic blood pressure maintenance in essential hypertension.

Arginine vasopressin (AVP) has been found to participate in blood pressure maintenance especially when other pressor systems are endogenously or pharmacologically impaired. The purpose of this study was to assess the pressor contribution of AVP to orthostatic blood pressure maintenance in otherwise healthy patients with essential hypertension. Twenty-seven patients were grouped according to age (young n = 13, elderly n = 14) and race (white n = 13, black n = 14). Integrity of autonomic nervous system (ANS) was assessed by Valsalva's maneuver, cold pressor test and head-up tilt. AVP contribution to blood pressure was estimated by the fall in mean arterial pressure in response to IV injection of 0.5 mg of a V1 AVP inhibitor (AVPi). Elderly subjects were found to have a mild (subclinical) ANS impairment as indicated by absence of bradycardia in phase 4 of Valsalva's maneuver and hypotension without concurrent tachycardia during head up tilt. Depressor responses to AVPi while subjects were in the upright position, were greater in elderly and blacks (-15 +/- 11 mm Hg and -15 +/- 12 mm Hg, respectively, P < .05) than young and whites (-8 +/- 6 and -7 +/- 6 mm Hg, respectively, ns). The greater importance of the AVP component in the elderly may be at least partially explained by a mild ANS impairement, whereas hormonal characteristics of hypertension in blacks may explain greater AVPi induced fall in mean arterial pressure. Our data show that both age and race influence the response to AVPi.

Effect of blood glucose on left ventricular mass in patients with hypertension and type 2 diabetes mellitus.

The aim of our prospective study was to evaluate the influence of blood glucose (BG) on left ventricular mass and diastolic function in patients with hypertension and type 2 diabetes mellitus (DM). Fifty-six hypertensive patients with type 2 DM and 26 healthy controls were investigated. They were submitted to echocardiography (ECHO) with Doppler and we calculated the mean of their fasting BG values, office blood pressure (OBP), cholesterol and fractions, and triglycerides during the previous 4 years. The diabetic patients were then followed-up for 1 year with OBP, fasting BG, and lipids measured every 2 months. After this period, the patients were again submitted to ECHO and in 22 patients (group I [GI]), reductions greater than 10% in left ventricular mass index (LVMI) were observed (122 +/- 35 v 89 +/- 23 g/m2, P < .01), whereas increases greater than 10% (group II [GII], n = 17) (94 +/- 18 v 115 +/- 27 g/m2, P < .01) or no changes (group III [GIII], n = 17) (98 +/- 16 v 99 +/- 18 g/m2, NS) in LVMI were detected in the remaining patients. The OBP values did not change during the follow-up. In GI the reduction of LVMI was associated with a BG fall from 178 +/- 36 to 147 +/- 30 mg/dL (P < .01) and a correlation was observed between BG and LVMI percent variations (delta) (r = 0.48, P < .01). No important changes in left ventricular diastolic function were observed during the follow-up. We concluded that the improvement in glycemic control may contribute to LVH regression in hypertensive patients with type 2 DM.

Parenteral isradipine reduces blood pressure in hypertensive crisis.

The efficacy and tolerability of an infusion of isradipine, a calcium antagonist of the dihydropyridine type, were tested in patients in hypertensive crisis. Ten patients with symptomatic and significant elevations in blood pressure were infused for 12 h with isradipine at 1.2, 2.4, 4.8, and 7.2 micrograms/kg/h (3 h of each infusion level). No untoward effects or adverse reactions were noted. No alterations were observed on electrocardiographic tracings, and blood pressure was significantly reduced only at doses of 7.2 micrograms/kg/h. Thus, isradipine as an infusion is useful and safe for hypertensive crisis, starting at a rate of 7.2 micrograms/kg/h. Higher doses may yet prove to be safe, well tolerated, and even more efficacious.

Nitric oxide, cholesterol oxides and endothelium-dependent vasodilation in plasma of patients with essential hypertension.

The objective of the present study was to identify disturbances of nitric oxide radical (.NO) metabolism and the formation of cholesterol oxidation products in human essential hypertension. The concentrations of.NO derivatives (nitrite, nitrate, S-nitrosothiols and nitrotyrosine), water and lipid-soluble antioxidants and cholesterol oxides were measured in plasma of 11 patients with mild essential hypertension (H: 57.8 +/- 9.7 years; blood pressure, 148.3 +/- 24.8/90.8 +/- 10.2 mmHg) and in 11 healthy subjects (N: 48.4 +/- 7.0 years; blood pressure, 119.4 +/- 9.4/75.0 +/- 8.0 mmHg). Nitrite, nitrate and S-nitrosothiols were measured by chemiluminescence and nitrotyrosine was determined by ELISA. Antioxidants were determined by reverse-phase HPLC and cholesterol oxides by gas chromatography. Hypertensive patients had reduced endothelium-dependent vasodilation in response to reactive hyperemia (H: 9.3 and N: 15.1% increase of diameter 90 s after hyperemia), and lower levels of ascorbate (H: 29.2 +/- 26.0, N: 54.2 +/- 24.9 micro M), urate (H: 108.5 +/- 18.9, N: 156.4 +/- 26.3 micro M), beta-carotene (H: 1.1 +/- 0.8, N: 2.5 +/- 1.2 nmol/mg cholesterol), and lycopene (H: 0.4 +/- 0.2, N: 0.7 +/- 0.2 nmol/mg cholesterol), in plasma, compared to normotensive subjects. The content of 7-ketocholesterol, 5alpha-cholestane-3beta,5,6beta-triol and 5,6alpha-epoxy-5alpha-cholestan-3alpha-ol in LDL, and the concentration of endothelin-1 (H: 0.9 +/- 0.2, N: 0.7 +/- 0.1 ng/ml) in plasma were increased in hypertensive patients. No differences were found for.NO derivatives between groups. These data suggest that an increase in cholesterol oxidation is associated with endothelium dysfunction in essential hypertension and oxidative stress, although.NO metabolite levels in plasma are not modified in the presence of elevated cholesterol oxides.

Intima-media thickness evaluation by B-mode ultrasound. Correlation with blood pressure levels and cardiac structures.

The aim of this study was to analyze the thickness of the intima-media complex (IMC) using a noninvasive method. The carotid and femoral common arteries were evaluated by noninvasive B-mode ultrasound in 63 normotensive and in 52 hypertensive subjects and the thickness of the IMC was tested for correlation with blood pressure, cardiac structures and several clinical and biological parameters. The IMC was thicker in hypertensive than in normotensive subjects (0.67 +/- 0.13 and 0.62 +/- 0.16 vs 0.54 +/- 0.09 and 0.52 +/- 0.11 mm, respectively, P<0.0001). In normotensive patients, the simple linear regression showed significant correlations between IMC and age, body mass index and 24-h systolic blood pressure for both the carotid and femoral arteries. In hypertensives the carotid IMC was correlated with age and 24-h systolic blood pressure while femoral IMC was correlated only with 24-h diastolic blood pressure. Forward stepwise regression showed that age, body mass index and 24-h systolic blood pressure influenced the carotid IMC relationship (r2 = 0.39) in normotensives. On the other hand, the femoral IMC relationship was influenced by 24-h systolic blood pressure and age (r2 = 0.40). In hypertensives, age and 24-h systolic blood pressure were the most important determinants of carotid IMC (r2 = 0.37), while femoral IMC was influenced only by 24-h diastolic blood pressure (r2 = 0.10). There was an association between carotid IMC and echocardiographic findings in normotensives, while in hypertensives only the left posterior wall and interventricular septum were associated with femoral IMC. We conclude that age and blood pressure influence the intima-media thickness, while echocardiographic changes are associated with the IMC.

Relationship between microalbuminuria and cardiac structural changes in mild hypertensive patients.

The aim of this study was to determine the relationship between urinary albumin excretion (UAE), cardiac structural changes upon echocardiography and 24-h ambulatory blood pressure (ABPM) levels. Twenty mild hypertensive patients (mean age 56.8 +/- 9.6 years) were evaluated. After 2 weeks of a washout period of all antihypertensive drugs, all patients underwent an echocardiographic evaluation, a 24-h ABPM and an overnight urine collection. Systolic and diastolic blood pressure during 24-h ABPM was 145 +/- 14/91 +/- 10 mmHg (daytime) and 130 +/- 14/76 +/- 8 mmHg (nighttime), respectively. Seven (35%) patients presented UAE > or = 15 microg/min, and for the whole group, the geometric mean value for UAE was 10.2 x// 3.86 microg/min. Cardiac measurements showed mean values of interventricular septum thickness (IVS) of 11 +/- 2.3 mm, left ventricular posterior wall thickness (PWT) of 10 +/- 2.0 mm, left ventricular mass (LVM) of 165 +/- 52 g, and left ventricular mass index (LVMI) of 99 +/- 31 g/m2. A forward stepwise regression model indicated that blood pressure levels did not influence UAE. Significant correlations were observed between UAE and cardiac structural parameters such as IVS (r = 0.71, P<0.001), PWT (r = 0.64, P<0.005), LVM (r = 0.65, P<0.005) and LVMI (r = 0.57, P<0.01). Compared with normoalbuminuric patients, those who had microalbuminuria presented higher values of all cardiac parameters measured. The predictive positive and negative values of UAE > or = 15 microg/min for the presence of geometric cardiac abnormalities were 75 and 91.6%. These data indicate that microalbuminuria in essential hypertension represents an early marker of cardiac structural damage.

Validation study of an automated wrist monitor, omron model HEM-608, compared with the standard methods for blood pressure measurement.

OBJECTIVE - The aim of our study was to assess the profile of a wrist monitor, the Omron Model HEM-608, compared with the indirect method for blood pressure measurement. METHODS - Our study population consisted of 100 subjects, 29 being normotensive and 71 being hypertensive. Participants had their blood pressure checked 8 times with alternate techniques, 4 by the indirect method and 4 with the Omron wrist monitor. The validation criteria used to test this device were based on the internationally recognized protocols. RESULTS - Our data showed that the Omron HEM-608 reached a classification B for systolic and A for diastolic blood pressure, according to the one protocol. The mean differences between blood pressure values obtained with each of the methods were -2.3 +7.9mmHg for systolic and 0.97+5.5mmHg for diastolic blood pressure. Therefore, we considered this type of device approved according to the criteria selected. CONCLUSION - Our study leads us to conclude that this wrist monitor is not only easy to use, but also produces results very similar to those obtained by the standard indirect method.

[Reversal of left ventricular hypertrophy after the use of benazepril]. / Reversão de hipertrofia ventricular esquerda após o uso de benazepril.

PURPOSE: To assess the effects of benazepril (ACE inhibitor) on arterial blood pressure (ABP) and left ventricular mass index (LVMI). METHODS: Nineteen patients (7 men, 12 women) with mean age 38.2 +/- 10.2 years, with mild to moderate hypertension were evaluated. Besides raised blood pressure, the necessary inclusion criterion was the presence of left ventricular hypertrophy detected by echocardiogram. After a wash-out period, all patients were given placebo followed by the active drug benazepril at a dose of 10 mg once a day. For those patients who did not achieve a satisfactory control of the blood pressure (BP) 25 mg of chlorthalidone was added. All patients underwent 180 days of benazepril treatment. RESULTS: The ABP was gradually controlled as follow: at seated position the systolic BP changed from 156.05 +/- 5.07 mmHg to 129 +/- 3.74 mmHg (p < 0.001) and the diastolic BP from 99.74 +/- 1.59 mmHg to 81.8 +/- 2.27 mmHg (p < 0.001). At orthostatic position the systolic BP changed from 156.9 +/- 5.35 mmHg to 124.28 +/- 5.33 mmHg (p < 0.001) and the diastolic BP from 101.7 +/- 1.34 to 81.36 +/- 2.81 (p < 0.001). The heart rate did not change significantly during the study. The LVMI decreased significantly from 182.4 +/- 9.2g/m2 to 122.6 +/- 4.2g/m2 (p < 0.001). CONCLUSION: Our data revealed that 100% of the patients achieved satisfactory degrees of LVMI regression and in 34% there was a normalization of it.

[Use of carvedilol compared to nifedipine in the treatment of mild and moderate essential arterial hypertension]. / O uso do carvedilol comparado à nifedipina no tratamento da hipertensão arterial essencial leve e moderada.

PURPOSE: To compare the efficacy of carvedilol, a new antihypertensive drug that combines vasodilatory and beta-blocker properties, with nifedipine. METHODS: In a multicenter double-blind trial, 106 mild to moderate essential hypertensive patients were treated with either carvedilol (n = 51), or nifedipine (n = 55) as monotherapy. Following 4 weeks of wash-out/run-in period, patients from the carvedilol group received this drug once a day at a dosage of 25 mg/day for 8 consecutive weeks. In order to maintain the double-blind character of the study, a placebo was administered in the carvedilol group at identical dosage intervals as used in the nifedipine s.r. group. Nifedipine was also administered for 8 weeks at a dosage of 40 mg/day given b.i.d. RESULTS: Both treatments were equally efficient in reducing blood pressure in the seated and upright positions. Blood pressure response to treatment was obtained in 79% and 78% of patients treated with carvedilol and nifedipine, respectively. The carvedilol group did not develop reflex tachycardia which is usually seen when prescribing vasodilators. Blood biochemistry remained unchanged with both treatments. Besides similar blood pressure efficacy, side effects by patients taking carvedilol were less frequent than nifedipine group. CONCLUSION: Carvedilol is a safe, efficient, once/day choice as monotherapy for mild to moderate essential hypertensive patients.

Distribution of cardiac geometric patterns on echocardiography in essential hypertension. Impact of two criteria of stratification.

PURPOSE: To evaluate 2 left ventricular mass index (LVMI) normality criteria for the prevalence of left ventricular geometric patterns in a hypertensive population ( HT ). METHODS: 544 essential hypertensive patients, were evaluated by echocardiography, and different left ventricular hypertrophy criteria were applied: 1 - classic : men - 134 g/m2 and women - 110 g/m2; 2- obtained from the 95th percentil of LVMI from a normotensive population (NT). RESULTS: The prevalence of 4 left ventricular geometric patterns, respectively for criteria 1 and 2, were: normal geometry - 47.7% and 39.3%; concentric remodelying - 25.4% and 14.3%; concentric hypertrophy - 18.4% and 27.7% and excentric hypertrophy - 8.8% and 16.7%, which confered abnormal geometry to 52.6% and 60.7% of hypertensive. The comparative analysis between NT and normal geometry hypertensive group according to criteria 1, detected significative stuctural differences,"( *p < 0.05):LVMI- 78.4 +/- 1.50 vs 85.9 +/-0.95 g/m2 *; posterior wall thickness -8.5 +/- 0.1 vs 8.9 +/- 0.05 mm*; left atrium - 33.3 +/- 0.41 vs 34.7 +/- 0.30 mm *. With criteria 2, significative structural differences between the 2 groups were not observed. CONCLUSION: The use of a reference population based criteria, increased the abnormal left ventricular geometry prevalence in hypertensive patients and seemed more appropriate for left ventricular hypertrophy detection and risk stratification.

Association of urinary 90 kDa angiotensin- converting enzyme with family history of hypertension and endothelial function in normotensive individuals.

We described angiotensin-I-converting enzyme (ACE) isoforms with molecular masses of 190, 90, and 65 kDa in the urine of normotensive offspring of hypertensive subjects. Since they did not appear in equal amounts, we suggested that 90 kDa ACE might be a marker for hypertension. We evaluated the endothelial response in normotensive offspring with or without family history of hypertension and its association with the 90 kDa ACE in urine. Thirty-five normotensive subjects with a known family history of hypertension and 20 subjects without a family history of hypertension, matched for age, sex, body weight, and blood pressure, were included in the study. Endothelial function was assessed by ultrasound and a sample of urine was collected for determination of ACE isoforms. In the presence of a family history of hypertension and detection of 90 kDa ACE, we noted a maximal flow mediated dilation of 12.1 +/- 5.0 vs 16.1 +/- 6.0% in those without a previous history of hypertension and lacking urinary 90 kDa ACE (P < 0.05). In subjects with a family history of hypertension and presenting 90 kDa ACE, there were lower levels of HDL-cholesterol (P < 0.05) and higher levels of triglycerides (P < 0.05). Subjects with 90 kDa ACE irrespective of hypertensive history presented a trend for higher levels of triglycerides and HDL-cholesterol (P = 0.06) compared to subjects without 90 kDa ACE. Our data suggest that the 90 kDa ACE may be a marker for hypertension which may be related to the development of early atherosclerotic changes.

Lipid peroxidation and antioxidants in hyperlipidemia and hypertension.

Lipid peroxidation and lipid-derived oxidized products have been implicated in the pathogenesis of a variety of human diseases. To clarify the role of oxidative stress in essential hypertension and hypercholesterolemia the in vitro oxidative susceptibility of LDL, the antioxidant status and the lipid peroxide content of blood plasma were examined in hypercholesterolemic (HC), hypertensive (H), hypercholesterolemic/hypertensive (HH) and normolipidemic/normotensive subjects (N). Plasma ascorbate and lipid-soluble antioxidants were lower, while LDL oxidizability, CE-OOH and TL-OOH were higher in H, HC, and HH groups than in the N group. No difference was observed among groups for PL-OOH and isoprostanes. In summary, the results show that: 1) lipid- and water-soluble antioxidants are lower in hypercholesterolemic and hypertensive patients as compared to normal subjects, whereas the lipid peroxide content and the LDL susceptibility to oxidation were higher; 2) total cholesterol, LDL-cholesterol, apoB and CE-OOH were negatively correlated with the content of a-tocopherol; 3) there was a positive correlation between the content of lipid-soluble antioxidants and the resistance of LDL to oxidation; and 4) CE-OOH and TL-OOH were positively correlated with total cholesterol and LDL-cholesterol.

Angiotensin converting-like enzymes from urine of untreated renovascular hypertensive and normal patients: purification and characterization.

Angiotensin converting-like enzymes (ACE) were isolated from urine of normal (P0N, P1N and P2N) and untreated renovascular hypertensive (P0, P1 and P2) patients. The urine were submitted to ion exchange chromatography. Enzymes P0 and P0N were eluted with the equilibrium buffer (0.02 M Tris-HCl, pH 7.0), while P1, P1N, P2 and P2N with ionic strength linear gradient of 0.02-0.5 M Tris-HCl, pH 7.0 in 0.7 mS and P2 and P2N in 1.2 mS conductance. The active fractions were submitted to gel filtration in Sephadex G-150, equilibrated and performed with 0.05 M Tris-HCl/0.15 M NaCl buffer, pH 8.0. All enzymes were homogeneous when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) (molecular mass: P0, P2 and P2N about 60 kDa; P1, 95 kDa and P21N 170 kDa). The enzymes were recognized by Y1 polyclonal antibody raised against human renal ACE. The K(M) values were in millimolar order for hippuryl-L-His-Leu (HHL) while for benzyloxycarbonyl-Phe-L-His-Leu (ZFHL) they were in 10(-4) M order. The enzymes were able to hydrolyze angiotensin I (AI) (P0 and P0N about 25%, P1 and P1N about 70%, P2 100% and P2N 66%) and bradykinin (BK) (P0N 22%, P1N 81%, P2N 62%, P0 and P1 50% and P2 35%), and their activities were inhibited by captopril.