Donate Help Contact The AHA Sign In Home
American Heart Association
Circulation Research
Search: search_blue_button Advanced Search
Circulation Research. 1982;50:812-821

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Arner, A.
Right arrow Articles by Uvelius, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Arner, A.
Right arrow Articles by Uvelius, B.

Circulation Research, Vol 50, 812-821, Copyright © 1982 by American Heart Association


ARTICLES

Force-velocity characteristics and active tension in relation to content and orientation of smooth muscle cells in aortas from normotensive and spontaneous hypertensive rats

A Arner and B Uvelius

Segments of abdominal aorta from spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats (20-25 weeks) were compared with respect to force production and dynamic mechanical properties. The preparations were mounted in vitro for determination of optimal length (lo) for active force, and then maximally stimulated (high-K+ solution, 10 mm Ca2+, 10(-5) m noradrenaline), and fixed for electron microscopy. Muscle cellular volume per mm vessel wall was significantly (p less than 0.01) higher in SHR (0.14 +/- 0.009 mm3, n = 7) compared to WKY (0.11 +/- 0.004 mm3, n = 7). Unchanged cell length and unaltered cross- sectional area (17 micrometers2) of nucleus containing cell profiles in SHR suggest an increased number of cells in the media. No difference was found in maximum force per unit cell area between SHR (271 +/- 31, n = 7) and WKY (305 +/- 49 mN/mm2, n = 7). Cell orientation was almost circular in both groups, showing that force was measured in parallel to the cell long axis. Aortic segments were mounted in an apparatus for quick-release experiments. They were maximally stimulated and force steps were imposed at peak of contractions. The series elastic component, characterized by the initial elastic recoils at 0.75 lo, has similar stiffness values in SHR and WKY. Velocities were measured 100 msec after release. The results were fitted to Hill's equation and maximum shortening velocity (Vmax) computed. No difference in Vmax was found at 0.75 lo (WKY: 0.048 +/- 0.005; SHR: 0.042 +/- 0.006 lo/s, n = 6 for both). At 0.85 lo, the data were corrected for passive tension (40% to total). Vmax at 0.85 lo was 0.071 +/- 0.009 lo/s (n = 5) for WKY, and 0.069 +/- 0.007 lo/s (n = 5) for SHR. Similar Vmax and force per cell cross-sectional area suggest similar characteristics of actomyosin interaction in SHR and WKY aorta.


This article has been cited by other articles:


Home page
Circ. Res.Home page
U. Wetzel, G. Lutsch, H. Haase, U. Ganten, and I. Morano
Expression of Smooth Muscle Myosin Heavy Chain B in Cardiac Vessels of Normotensive and Hypertensive Rats
Circ. Res., July 27, 1998; 83(2): 204 - 209.
[Abstract] [Full Text] [PDF]