Abstract
Using high-resolution intravital charge-coupled device video microscopy, we visualized the epicardial capillary network of the beating canine heart in vivo to elucidate its functional, role under control conditions, during reactive hyperemia (RH), and during intracoronary adenosine administration. The pencillens video-microscope probe was placed over capillaries fed by the left anterior descending artery in atrioventricular-blocked hearts of open-chest, anesthetized dogs paced at 60-90 beats/min (n = 17). In individual capillaries under control conditions, red blood cell flow was predominant during systole or diastole, indicating that the watershed between diastolic arterial and systolic venous flows is located within the capillaries. Capillary flow increased during RH and reached a peak flow velocity (2.1 ± 0.6 mm/s), twice as high as control (1.2 ± 0.5 mm/s), with enhancement of intercapillary cross-connection flow and enlargement of diameter (by 17%). With adenosine, capillary flow velocity significantly increased (1.8 ± 0.7 mm/s). However, the increase in volumetric capillary flow with adenosine estimated from red blood cell velocity and diameter was less than the increase in arterial flow, whereas that during RH was nearly equivalent to the increase in arterial flow. There was a time lag of ≃1.5 s for refilling of capillaries during RH, indicating their function as capacitance vessels. In conclusion, the coronary capillary network functions as 1) the major watershed between diastolic-dominant arterial and systolic-dominant venous flows, 2) a capacitor, and 3) a significant local flow amplifier and homogenizer of blood supply during RH, but with adenosine the increase in capillary flow velocity was less than the increase in arterial flow.
| Original language | English |
|---|---|
| Journal | American Journal of Physiology - Heart and Circulatory Physiology |
| Volume | 288 |
| Issue number | 3 57-3 |
| DOIs | |
| Publication status | Published - Mar 2005 |
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Keywords
- In vivo imaging
- Microcirculation
- Unstressed volume
- Watershed
ASJC Scopus subject areas
- Physiology
Cite this
Direct observation of epicardial coronary capillary hemodynamics during reactive hyperemia and during adenosine administration by intravital video microscopy. / Kiyooka, Takahiko; Hiramatsu, Osamu; Shigeto, Fumiyuki; Nakamoto, Hiroshi; Tachibana, Hiroyuki; Yada, Toyotaka; Ogasawara, Yasuo; Kajiya, Masahito; Morimoto, Taro; Morizane, Yuki; Mohri, Satoshi; Shimizu, Juichiro; Ohe, Tohru; Kajiya, Fumihiko.
In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 288, No. 3 57-3, 03.2005.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct observation of epicardial coronary capillary hemodynamics during reactive hyperemia and during adenosine administration by intravital video microscopy
AU - Kiyooka, Takahiko
AU - Hiramatsu, Osamu
AU - Shigeto, Fumiyuki
AU - Nakamoto, Hiroshi
AU - Tachibana, Hiroyuki
AU - Yada, Toyotaka
AU - Ogasawara, Yasuo
AU - Kajiya, Masahito
AU - Morimoto, Taro
AU - Morizane, Yuki
AU - Mohri, Satoshi
AU - Shimizu, Juichiro
AU - Ohe, Tohru
AU - Kajiya, Fumihiko
PY - 2005/3
Y1 - 2005/3
N2 - Using high-resolution intravital charge-coupled device video microscopy, we visualized the epicardial capillary network of the beating canine heart in vivo to elucidate its functional, role under control conditions, during reactive hyperemia (RH), and during intracoronary adenosine administration. The pencillens video-microscope probe was placed over capillaries fed by the left anterior descending artery in atrioventricular-blocked hearts of open-chest, anesthetized dogs paced at 60-90 beats/min (n = 17). In individual capillaries under control conditions, red blood cell flow was predominant during systole or diastole, indicating that the watershed between diastolic arterial and systolic venous flows is located within the capillaries. Capillary flow increased during RH and reached a peak flow velocity (2.1 ± 0.6 mm/s), twice as high as control (1.2 ± 0.5 mm/s), with enhancement of intercapillary cross-connection flow and enlargement of diameter (by 17%). With adenosine, capillary flow velocity significantly increased (1.8 ± 0.7 mm/s). However, the increase in volumetric capillary flow with adenosine estimated from red blood cell velocity and diameter was less than the increase in arterial flow, whereas that during RH was nearly equivalent to the increase in arterial flow. There was a time lag of ≃1.5 s for refilling of capillaries during RH, indicating their function as capacitance vessels. In conclusion, the coronary capillary network functions as 1) the major watershed between diastolic-dominant arterial and systolic-dominant venous flows, 2) a capacitor, and 3) a significant local flow amplifier and homogenizer of blood supply during RH, but with adenosine the increase in capillary flow velocity was less than the increase in arterial flow.
AB - Using high-resolution intravital charge-coupled device video microscopy, we visualized the epicardial capillary network of the beating canine heart in vivo to elucidate its functional, role under control conditions, during reactive hyperemia (RH), and during intracoronary adenosine administration. The pencillens video-microscope probe was placed over capillaries fed by the left anterior descending artery in atrioventricular-blocked hearts of open-chest, anesthetized dogs paced at 60-90 beats/min (n = 17). In individual capillaries under control conditions, red blood cell flow was predominant during systole or diastole, indicating that the watershed between diastolic arterial and systolic venous flows is located within the capillaries. Capillary flow increased during RH and reached a peak flow velocity (2.1 ± 0.6 mm/s), twice as high as control (1.2 ± 0.5 mm/s), with enhancement of intercapillary cross-connection flow and enlargement of diameter (by 17%). With adenosine, capillary flow velocity significantly increased (1.8 ± 0.7 mm/s). However, the increase in volumetric capillary flow with adenosine estimated from red blood cell velocity and diameter was less than the increase in arterial flow, whereas that during RH was nearly equivalent to the increase in arterial flow. There was a time lag of ≃1.5 s for refilling of capillaries during RH, indicating their function as capacitance vessels. In conclusion, the coronary capillary network functions as 1) the major watershed between diastolic-dominant arterial and systolic-dominant venous flows, 2) a capacitor, and 3) a significant local flow amplifier and homogenizer of blood supply during RH, but with adenosine the increase in capillary flow velocity was less than the increase in arterial flow.
KW - In vivo imaging
KW - Microcirculation
KW - Unstressed volume
KW - Watershed
UR - http://www.scopus.com/inward/record.url?scp=13944260853&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=13944260853&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.00088.2004
DO - 10.1152/ajpheart.00088.2004
M3 - Article
C2 - 15345479
AN - SCOPUS:13944260853
VL - 288
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0002-9513
IS - 3 57-3
ER -