Acute, quercetin-induced reductions in blood pressure in hypertensive individuals are not secondary to lower plasma angiotensin-converting enzyme activity or endothelin-1: nitric oxide

2012 ◽  
Vol 32 (8) ◽  
pp. 557-564 ◽  
Author(s):  
Abigail Larson ◽  
Melissa A.H. Witman ◽  
Yi Guo ◽  
Stephen Ives ◽  
Russell S. Richardson ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Enzyme Activity ◽  
Angiotensin Converting Enzyme ◽  
Converting Enzyme ◽  
Lower Plasma ◽  
Angiotensin Converting Enzyme Activity ◽  
Endothelin 1 ◽  
Plasma Angiotensin ◽  
Plasma Angiotensin Converting Enzyme

Renoprotective Differences between Perindopril and Enalapril in the Diabetic Hypertensive Rat Do Not Reflect Glomerular Angiotensin-Converting Enzyme Activity

1998 ◽  
Vol 94 (5) ◽  
pp. 511-516 ◽  
Author(s):  
K. A. Duggan ◽  
G. Hodge ◽  
M. M. Makarious ◽  
J. A. Charlesworth
Keyword(s):  
Enzyme Activity ◽  
Angiotensin Converting Enzyme ◽  
Protein Content ◽  
Protein Accumulation ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme Activity ◽  
Spontaneous Hypertensive Rat ◽  
Hypertensive Rat ◽  
Plasma Angiotensin ◽  
Plasma Angiotensin Converting Enzyme

1. The various angiotensin-converting enzyme inhibitors have structural differences which affect their affinities for the catalytic sites on converting enzyme. We postulated that such differences might result in differences in renoprotective efficacy. We investigated this in the diabetic spontaneous hypertensive rat. We also investigated whether these differences might reflect variations in glomerular or plasma angiotensin-converting enzyme activity. 2. One week after induction of diabetes, rats were started on antihypertensive therapy: enalapril, 10 mg · day−1 · kg−1, or perindopril, 4 mg · day−1 · kg−1, in the drinking water. After 3 months, the rats were killed, blood samples were taken and tissues were harvested. Angiotensin-converting enzyme activity in isolated glomeruli and plasma was measured by fluorimetric assay. Glomerular protein content was also determined. 3. Urinary protein excretion was significantly lower in perindopril-treated rats than in either controls (P < 0.0005) or enalapril-treated rats P < 0.05). Glomerular protein content was also lower in perindopril-treated rats (P < 0.05 versus enalapril; P < 0.005 versus control). There was no difference in glomerular angiotensin-converting enzyme activity between the two inhibitors although both were lower than control values (enalapril P < 0.025; perindopril P < 0.025). Plasma angiotensin-converting enzyme activity was significantly lower in the perindopril group than in either control (P < 0.005) or the enalapril group (P < 0.01). 4. We conclude that in the spontaneous hypertensive rat with streptozotocin-induced diabetes, perindopril is more effective than enalapril in reducing proteinuria and glomerular protein accumulation. This difference does not result from differences in glomerular-converting enzyme activity.

scholarly journals Why is Plasma Angiotensin-Converting Enzyme Activity Elevated in Hyperthyroidism?

1987 ◽  
Vol 80 (8) ◽  
pp. 484-485
Author(s):  
J E Roulston ◽  
A Gold ◽  
M Wright ◽  
S W Walker
Keyword(s):  
Enzyme Activity ◽  
Angiotensin Converting Enzyme ◽  
Thyroid Hormones ◽  
Direct Effect ◽  
Tissue Damage ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme Activity ◽  
Plasma Angiotensin ◽  
Specific Tissue ◽  
Plasma Angiotensin Converting Enzyme

The elevation in plasma angiotensin-converting enzyme (ACE) levels observed in patients with hyperthyroidism is unexplained. In this study three hypotheses were investigated. Results from a study using rats treated with thyroid hormones indicated that the increased ACE was not due to increased cleavages of enzyme from lung endothelia. Data from patients with specific tissue damage argue against a nonspecific release of ACE from damaged cells. Data from cultured cell experiments, however, strongly support a direct effect of thyroid hormones upon ACE synthesis and secretion.

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