| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Physiology, Akdeniz University Faculty of Medicine, Antalya, Turkey
2 Department of Pharmacology, Akdeniz University Faculty of Medicine, Antalya, Turkey
3 Department of Physiology and Biophysics, University of Southern California, Keck School of Medicine, Los Angeles, California, USA
* To whom correspondence should be addressed. E-mail: baskurt{at}akdeniz.edu.tr.
The effects of enhanced re d blood cell (RBC) aggregation on nitric oxide (NO) dependent vascular control mechanisms have been investigated in a rat exchange transfusion model. RBC aggregation for cells in native plasma was increased via a novel method using RBC covalently coated w ith a 13 kDa poloxamer copolymer (Pluronic F98); control experiments used RBC coated with a non-aggregating 8.4 kDa poloxamer (Pluronic F68). Rats exchange-transfused with aggregating RBC suspensions demonstrated significantly enhanced RBC aggregation throughout the five day follow-up period, with mean arterial blood pressure increasing gradually over this period. Arterial segments (~300 µm diameter) were isolated from gracilis muscle on the fifth day and mounted between two glass micropipettes in a special chamber equipped with pressure servo control system. Dose dependent dilation by acetylcholine and flow-mediated dilation of arterial segments pressurized to 30 mmHg and pre-constricted to 45-55% of the original diameter by phenylephrine were significantly blunted in rats with enhanced RBC aggregation. Both responses were totally abolished by non-specific NOS inhibitor (L-NAME) treatment of arterial segments, indicating that the responses were NO-related. Additionally, expression of eNOS protein was found to be decreased in muscle samples obtained from rats exchanged with aggregating cell suspensions. These results imply that enhanced RBC aggregation results in suppressed expression of NO synthesizing mechanisms, thereby leading to altered vasomotor tonus: the mechanisms involved most likely relate to decreased wall shear stresses due to decreased blood flow and/or increased axial accumulation of RBC.
This article has been cited by other articles:
|
|
 |
|
  O. Yalcin, P. Ulker, U. Yavuzer, H. J. Meiselman, and O. K. Baskurt Nitric oxide generation by endothelial cells exposed to shear stress in glass tubes perfused with red blood cell suspensions: role of aggregation Am J Physiol Heart Circ Physiol, May 1, 2008; 294(5): H2098 - H2105. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Kim, R. L. Kong, A. S. Popel, M. Intaglietta, and P. C. Johnson Temporal and spatial variations of cell-free layer width in arterioles Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1526 - H1535. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Connes, O. Yalcin, O. Baskurt, J.-F. Brun, and M. Hardeman In health and in a normoxic environment, VO2 max is/is not limited primarily by cardiac output and locomotor muscle blood flow J Appl Physiol, June 1, 2006; 100(6): 2099 - 2099. [Full Text] [PDF]
|
|
|
|
|
|
S. Kim, A. S. Popel, M. Intaglietta, and P. C. Johnson Effect of erythrocyte aggregation at normal human levels on functional capillary density in rat spinotrapezius muscle Am J Physiol Heart Circ Physiol, March 1, 2006; 290(3): H941 - H947. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Yalcin, F. Aydin, P. Ulker, M. Uyuklu, F. Gungor, J. K. Armstrong, H. J. Meiselman, and O. K. Baskurt Effects of red blood cell aggregation on myocardial hematocrit gradient using two approaches to increase aggregation Am J Physiol Heart Circ Physiol, February 1, 2006; 290(2): H765 - H771. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Yalcin, M. Uyuklu, J. K. Armstrong, H. J. Meiselman, and O. K. Baskurt Graded alterations of RBC aggregation influence in vivo blood flow resistance Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2644 - H2650. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Levin, R. Gamzu, Y. Hasson, J.B. Lessing, A. Amit, I. Shapira, S. Berliner, and B. Almog Increased erythrocyte aggregation in ovarian hyperstimulation syndrome: a possible contributing factor in the pathophysiology of this disease Hum. Reprod., May 1, 2004; 19(5): 1076 - 1080. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
