Distribution and Properties of Angiotensin-Converting Enzyme in Cerebral Microvessels of the Rabbit and Rat

1981 ◽  
Vol 61 (s7) ◽  
pp. 249s-251s ◽  
Author(s):  
P. Brecher ◽  
Vandana Hingorani ◽  
Karen Reininga ◽  
A. V. Chobanian
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Rat Brain ◽  
Lipoprotein Lipase ◽  
Rabbit Brain ◽  
Aortic Tissue ◽  
Converting Enzyme ◽  
Cerebral Microvessels ◽  
Cerebral Microvasculature ◽  
Ace Activity

1. Angiotensin-converting enzyme (ACE) activity was threefold greater in isolated cerebral microvessels obtained from rabbit brain than rat brain. 2. ACE activity was distributed throughout the cerebral microvasculature, since differences were not found between preparations enriched in capillaries as compared with those enriched in arterioles and venules. 3. Aortic tissue from rat and rabbit had little ACE activity compared with the microvessels. 4. ACE activity was tightly associated with endothelial cells and was not released by heparin under conditions where lipoprotein lipase was effectively removed.

Hormonal influence on endothelial cell angiotensin-converting enzyme activity

1984 ◽  
Vol 247 (3) ◽  
pp. C163-C168 ◽  
Author(s):  
A. H. Krulewitz ◽  
W. E. Baur ◽  
B. L. Fanburg
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Protein Content ◽  
Hormonal Regulation ◽  
Converting Enzyme ◽  
Cell Counts ◽  
Ace Activity ◽  
Sites Of Action ◽  
Culture Supernatants

The influence of various hormones on angiotensin-converting enzyme (ACE) production and release by bovine endothelial cells in culture was studied. Dexamethasone, thyroxine (T4), and triiodothyronine (T3) stimulated ACE activity in cells and their culture supernatants without affecting cell number or protein content. The stimulating effects of dexamethasone and thyroid hormones were additive, suggesting that these hormones may have different sites of action. In addition, their stimulating effects were blocked by cycloheximide, indicating that increased enzymatic activity occurred through new protein synthesis. The exposure of cells to insulin reduced ACE activity of cells and their culture supernatants without influencing cell counts or protein content; insulin also partially inhibited the stimulation of ACE activity by dexamethasone or T3. Our studies suggest that the production of ACE by endothelial cells is under hormonal regulation. Release of ACE activity into culture supernatants parallels changes in cellular ACE activity. The results supplement previous observations made in vitro and in vivo.

Effects of Hoe 065, a compound structurally related to inhibitors of angiotensin converting enzyme, on acetylcholine metabolism in rat brain

1989 ◽  
Vol 166 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Gabriele Wiemer ◽  
Reinhard Becker ◽  
Hermann Gerhards ◽  
Franz Hock ◽  
Jens Stechl ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Rat Brain ◽  
Converting Enzyme ◽  
Acetylcholine Metabolism

Effect of angiotensin-converting-enzyme inhibition on bradykinin metabolism by vascular endothelial cells

1993 ◽  
Vol 264 (5) ◽  
pp. H1493-H1497 ◽  
Author(s):  
M. Grafe ◽  
C. Bossaller ◽  
K. Graf ◽  
W. Auch-Schwelk ◽  
C. R. Baumgarten ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Vascular Endothelial Cells ◽  
Ace Inhibition ◽  
Angiotensin Converting Enzyme Inhibition ◽  
Dependent Manner ◽  
Converting Enzyme ◽  
Concentration Dependent Manner ◽  
Cell Monolayers ◽  
Converting Enzyme Inhibition

The degradation of bradykinin by angiotensin-converting-enzyme (ACE) activity in cultured human endothelial cells was studied by direct measurement of bradykinin and by its effect on the release of endothelium-derived relaxing factors. The half-life of exogenous bradykinin (10,000 pg/ml) was calculated from the decay of the bradykinin concentration as 46 +/- 2 min in cell monolayers, 133 +/- 15 min in conditioned medium, and 24 +/- 2 min in homogenates. Most of the bradykinin-degrading activity in cell monolayers could be inhibited in a concentration-dependent manner by the ACE inhibitors lisinopril, ramiprilat, and captopril. Bradykinin-degrading activity was released into the culture medium containing one-fourth of the bradykinin-degrading activity found in the presence of cell monolayers. In cell homogenates higher unspecific bradykinin-degrading activities were present. The functional consequence of bradykinin degradation was demonstrated by the potentiating effect of ramiprilat on the generation of endothelium-derived relaxing factors nitric oxide and prostacyclin from endothelial cells. The study supports the concept of increased vasodilatory effects of bradykinin during ACE inhibition.

Sign in / Sign up

Export Citation Format

Share Document