Yoshi-Ichiro Kamijo M.D., Ph.D.
Assistant professor
Department. of Sports Medical Sciences,
Dr. Yoshi-Ichiro Kamijo received M.D. degree from Shinshu
University School of Medicine in 1997. He received his Ph.D. degree from the
graduate school of the university in 2001 under supervision by prof. Hiroshi
Nose. Then, he worked with Dr Gary W. Mack in John B. Pierce Laboratory at Yale
University School of Medicine as a postdoctoral fellow. He came back to Matsumoto in 2003, and
is working again in the university.
His research interest is on the cardiovascular and thermoregulatoy
regulations in dehydrated and exercising humans.
Effects
of hyperosmolality on maintenance of arterial pressure in dehydrated and exercising
humans.
Hypovolemia
due to dehydrationis known to suppress cutaneous vasodilation by unloading of
baroreceptors during exercise, which is believed to maintain arterial pressure.
Although hyperosmolality also is reported to suppress cutaneous vasodilation
by stimulating the central osmoreceptors, it is unclear whether it contributes
to the maintenance of arterial pressure during exercise. Recently, we found in dehydrated and
exercising subjects that drinking such a small amount of water not to change
plasma osmolality and plasma volume
releases hyperosmotic suppression of cutaneous vasodilation, resulting
in a transient fall in arterial pressure.
These results suggest that hyperosmolality is one of the pressor stimulations
during exercise in dehydrated subjects.