2004 Fiscal Year Final Research Report Summary
In vivo study for non-linear relationship between capillary blood flow and tissue pO_2 in skeletal muscle
| Project/Area Number |
15300156
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Biomedical engineering/Biological material science
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
SHIBATA Masahiro The University of Tokyo, Graduate School of Medicine, Lecturer, 大学院・医学系研究科, 講師 (60158954)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KAMIYA Akira Nihon University, Graduate School of Global Business, Professor, 大学院・グローバルビジネス研究科, 教授 (50014072)
|
|---|
| Project Period (FY) |
2003 – 2004
|
| Keywords | oxygen / arterioles / capillaries / microcirculation / skeletal muscle / 骨格筋 |
|---|
| Research Abstract |
We tested the hypothesis that skeletal muscle may have a simple, intrinsic O_2-sensing mechanism for regulating capillary blood flow in which capillary flow is started and stopped in response to a threshold pO_2 value. This hypothesis was evaluated by measuring the capillary red blood cell (RBC) velocity and perfused capillary density in response to changes in the pO_2 level of suffusates in rabbit tenuissimus muscle using an intravital microscope. Both the RBC velocity and the capillary density significantly decreased as the pO_2 level of the suffusates was elevated, but the relationship between the capillary blood flow rate, calculated by the velocity and density data, and the pO_2 level of the suffusates displayed a non-linear correlation. This data suggests that a critical pO_2 value affecting microvascular blood flow regulation might exist for suffusates with a pO_2 of between 35 and 45 Torr. Above or below this critical threshold pO_2 level, capillary blood flow drastically decreases or increases. These findings support the possibility that the arterioles play an important role in detecting local metabolic demand and directly regulate capillary blood flow by influencing the tonus of their smooth muscle, without requiring signal transmission from a distal site.
|
