Studies on zinc and angiotensin-converting enzyme

Buttery, J E; Stuart, Sandra

doi:10.1016/0009-8981(93)90168-4

Cited by 6 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3.4.15.1), also known as kininase II, is a zinc-requiring metalloenzyme. 4 It is a membrane-bound glycoprotein, localized mainly in the endothelial cells of pulmonary capillaries. ACE catalyzes the cleavage of histidyl-leucine from the carboxyl-terminal of AI, yielding an octapeptide angiotensin II (AII), and it inactivates bradykinin.…”

Section: Introductionmentioning

confidence: 99%

The study of renin-angiotensin-aldosterone in experimental diabetes mellitus

Üstündağ

Çay

Nazıroğlu

et al. 1999

Cell Biochem. Funct.

View full text Add to dashboard Cite

It is generally accepted that hypertension and other vascular pathologies increase in diabetes mellitus (DM) patients as a result of the renin-angiotensin-aldosterone (RAA) system. In this study, changes in the renin-angiotensin-aldosterone (RAA) system level was determined in Streptozotocin (STZ)-injected rats. A total of 46 female Wistar albino rats (180-220 g body weight) was utilized in these experiments. STZ was given intraperitoneally to induce diabetes in rats. Streptozotocin (60 mg kg(-1) body weight) was dissolved in 0.1 m citrate--phosphate buffer (pH 4-5). The non-diabetic rats were injected with sterilized buffer alone to act as a control group. Blood glucose levels were 398+/-8.2 mg dl(-1), 488+/-11.75 mg dl(-1) and 658+/-29.6 mg dl(-1) at days 3, 12 and 30 respectively. The level of plasma renin activity (PRA) was measured as 7.69+/-1.07 ng ml(-1) h(-1); 1.82+/-0.22 ng ml(-1) h(-1) and 0. 67+/-0.12 ng ml(-1) h(-1) at days 3, 12 and 30, respectively. These values showed that the PRA levels are decreased with increased time period. Serum angiotensin converting enzyme (ACE, E.C. 3.4.15.1) levels were increased at days 12 and 30 (p<0.05 and p<0.005), whereas serum aldosterone levels were increased at days 3 and 12 (p<0.05). The level of urea and creatinine increased at days 12 and 30 (p<0.05 and p<0.005, respectively) when compared to the control group. The data from these experiments indicate that the PRA level decreased whereas ACE activity level increased in diabetic rats compared with the control. Aldosterone levels increased at the first stage of the experiment, but then decreased by the end of the experiment as a result of changes in renin and ACE levels.

show abstract

Section: Introductionmentioning

confidence: 99%

The study of renin-angiotensin-aldosterone in experimental diabetes mellitus

Üstündağ

Çay

Nazıroğlu

et al. 1999

Cell Biochem. Funct.

View full text Add to dashboard Cite

show abstract

“…The solution was ultracentrifuged at 100,000 g for 20 min and the supernatant was dialyzed overnight with 10 mM HEPES buffer, pH 7.5, containing 0.3 M KCI and 100 pM ZnCh (2 x 2 liters). 50 pl of dialyzed solution were assayed for ACE activity evaluated by FAPGG hydrolytic activity, following the kinetic ACE methods as proposed (4). Ovary Triton-X100 extraction, protease inhibitors were added immediately to the homogenized sample: PMSF (500 pM), pepstatin (1 pM), leupeptin (5 pM) and antipain (25 pM) (final concentrations) and the resulting pellet after ultracentrifugation at 100,000 g for 20 min was resuspended in 4 ml of phosphate buffer with all the protease inhibitors and Triton-X100 was added to a final concentration of 1% (v/v) (16).…”

Section: Methodsmentioning

confidence: 99%

La enzima convertidora de angiotensina purificada de ovario de Rana esculenta influye en la síntesis de esteroides in vitro

Miano

Quassinti

Maccari

et al. 2003

J. Physiol. Biochem.

View full text Add to dashboard Cite

The aim of the present study was to purify and characterize angiotensin-converting enzyme (ACE) present in frog ovary (Rana esculenta). Detergent and trypsin-extracted enzymes were purified using a one-step process, consisting of affinity chromatography on lisinopril coupled to Sepharose 6B. The molecular mass was 150 kDa for both detergent-extracted and trypsin-extracted enzyme. The specific activity of detergent-extracted and trypsin-extracted ACE was 294 U mg(-1) and 326 U mg(-1) respectively. The optimum pH range was from 7-8.5 at 37 degrees C and the optimum temperature was 50 degrees C. Optimum chloride concentration was about 200 mM for synthetic substrate FAPGG (N-[3-(2-furyl)acryloyl] L-phenylalanyl glycyl glycine) and angiotensin I, and 10 mM for bradykinin. The Km and Kcat values for FAPGG were 0.608 +/- 0.07 mM and 249 sec(-1) respectively and I50 values for captopril and lisinopril, two specific ACE inhibitors, were 68 +/- 12.55 nM and 6.763 +/- 0.66 nM respectively. Frog ovary tissue from prereproductive period was incubated in vitro in the presence of frog ovary ACE (2.5 mU/ml), captopril (0.1 mM), and lisinopril (0.1 mM). Production of 17beta-estradiol, progesterone, and prostaglandins E2 and F2alpha was determined. The data showed a modulation of 17beta-estradiol, progesterone and prostaglandin E2 production by ovary ACE.

show abstract

Angiotensin converting enzyme (ACE) activity levels in insulin-independent diabetes mellitus and effect of ACE levels on diabetic patients with nephropathy

Üstündağ

Canatan

Cinkilinc

et al. 2000

Cell Biochem. Funct.

View full text Add to dashboard Cite

Involvement of complications is considered to be one of the major factors in the prognosis of diabetes mellitus (DM). Recent studies indicate that most diabetic complications such as nephropathy and hypertension are vascular-originated. Renin-angiotensin involvement, especially changes in ACE activity level, is considered to be a key factor since ACE converts angiotensin I to angiotensin II which is a potent vasoconstrictor and plays a vital role in the regulation of blood pressure. Our present study focused on ACE activity levels along with blood glucose and HbA(1c) levels in diabetic patients with (n=18) or without (n=25) nephropathy as compared to control subjects (n=25). Blood glucose levels were significantly higher in both diabetic groups compared to controls (p<0.001). On the other hand, compared to controls, blood HbA(1c) levels were slightly higher in DM patients without complications whereas they were significantly increased in nephropatic DM patients (p<0.001). There was a very strong increase (p<0.001) at the level of ACE activity in both of the diabetic groups (with nephropathy: 47.11+/-3.70 U l(-1); without complications: 43.72+/-2.93 U l(-1); controls: 25.15+/-2.30 U l(-1)). ACE activity levels were also significantly higher in diabetic patients with nephropathy than in type II DM patients without complication (p<0.01). Our results demonstrate that ACE activity levels are increased in diabetic patients. Additional significant increase in ACE activity levels in diabetic patients with complications such as nephropathy supports the hypothesis that ACE activity has an essential role in the development of complications in diabetes.

show abstract

Studies on zinc and angiotensin-converting enzyme

Cited by 6 publications

References 6 publications

The study of renin-angiotensin-aldosterone in experimental diabetes mellitus

The study of renin-angiotensin-aldosterone in experimental diabetes mellitus

La enzima convertidora de angiotensina purificada de ovario de Rana esculenta influye en la síntesis de esteroides in vitro

Angiotensin converting enzyme (ACE) activity levels in insulin-independent diabetes mellitus and effect of ACE levels on diabetic patients with nephropathy

Contact Info

Product

Resources

About