Acute pancreatitis in rats: effects of sodium taurocholate, CCK-8, and Sec on pancreatic microcirculation

1997 ◽  
Vol 272 (2) ◽  
pp. G310-G320 ◽  
Author(s):  
T. Plusczyk ◽  
S. Westermann ◽  
D. Rathgeb ◽  
G. Feifel
Keyword(s):  
Blood Flow ◽  
Pancreatic Duct ◽  
Capillary Permeability ◽  
Sodium Taurocholate ◽  
Capillary Density ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Biliary Pancreatitis ◽  
Acute Biliary Pancreatitis

With use of in vivo microscopy, pancreatic duct permeability, red blood cell (RBC) velocities, functional capillary density (FCD), and overall changes in capillary blood flow (perfusion index) were estimated after intraductal infusion of sodium taurocholate (0.8 ml, 4%) alone or in combination with systemic administration of cholecystokinin (CCK, 0.3 microg/100 g body wt) or secretin (Sec, 10 microg/100 g body wt). Sodium taurocholate mediated a significant increase in pancreatic duct and capillary permeability within 105 +/- 26 s followed by a transient decrease in RBC velocities and a sustained decrease in FCD, which were paralleled by dramatic flow heterogeneity. Therefore, a significant reduction in overall capillary blood flow was calculated. CCK stimulation aggravated the microcirculatory failure due to a decrease in RBC velocities, which was accompanied by an increase in acinar cellular necrosis. Sec stimulation attenuated microcirculatory failure due to a more moderate reduction of FCD. The enhanced pancreatic duct and capillary permeability, which enables free diffusion of pancreatic digestive enzymes into the parenchyma, is the initiating event in acute biliary pancreatitis, causing microcirculatory failure and tissue damage. The microcirculatory changes are secondary and a propagating factor for the development of acini necrosis. Stimulation with CCK worsened the course of acute biliary pancreatitis.

In Vivo Fluorescence Microscopy of Microcirculation in the Renal Cortex of Mice

1993 ◽  
Vol 34 (2) ◽  
pp. 168-173 ◽  
Author(s):  
B. Högström ◽  
P. Rooth ◽  
O. Sunnegårdh ◽  
S.-O. Hietala
Keyword(s):  
Blood Flow ◽  
Fluorescence Microscopy ◽  
Experimental Model ◽  
Rating Scale ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Cortical Blood Flow ◽  
In Vivo Fluorescence ◽  
Renal Cortical Blood Flow

An experimental model using in vivo fluorescence microscopy for studies of renal cortical blood flow was tested in 40 mice. The model was suitable for testing a wide variety of hypotheses concerning alterations in renal cortical blood flow, including the possibility of inhomogeneous capillary blood flow distribution in response to i.v. infusions. The experimental model was tested for the effects of i.v. infusion of mannitol (0.3 mol/l). Effects of anesthesia and mechanical kidney fixation on renal cortical blood flow were studied. Neuroleptic analgesia was less hazardous to the animals than pentobarbital. Due to artifacts from respiratory and peristaltic motion, it was not possible to use neuroleptic analgesia without mechanical kidney fixation. A rating scale was designed for evaluating the capillary blood flow. The correlation between repeated ratings by the same observer was 0.806 and between 2 different observers 0.59.

Motion Artifact Compensation for Wristwatch Type Photoplethysmography Sensor

2012 ◽  
Vol 523-524 ◽  
pp. 639-644 ◽  
Author(s):  
Daisuke Horiguchi ◽  
Hiroki Naito ◽  
Ken Sasaki
Keyword(s):  
Blood Flow ◽  
Capillary Density ◽  
Heart Beat ◽  
Capillary Blood ◽  
The Body ◽  
Body Motion ◽  
Capillary Blood Flow ◽  
Body Acceleration ◽  
Sensor Orientation ◽  
The Relationship

Heart beat measurement is useful not just for medical use but also for daily healthcare monitoring and for sports. Photoplethysmography is an optical pulse measurement method that measures the variation of light absorption of the blood flow in capillary. Fingertip and earlobe, which are suitable places for this method, are not suitable for wearing sensors in daily life. Measurement at wrist will be more favorable. Technical difficulties of applying photoplethysmography measurement on wrist are: a) blood flow variation and change of sensor orientation caused by body motions, and b) low sensitivity compared to measurement at fingertips or earlobes because of the low capillary density in the tissue. We derived a transfer function that expresses the relationship between body acceleration and change in capillary blood flow based on a simple fluid dynamics model of artery and capillary. Preliminary experiments have shown that motion the artifacts can be reduced by subtracting the change of blood flow estimated from body acceleration. This method is different from conventional frequency filtering methods that do not consider the relationship between the body motion and the changes in the capillary blood flow. Furthermore, sensor head suspension mechanism has been employed in order to stabilize the sensor orientation with respect to the skin as well as the applied force on the skin.

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