Incorporation of the Time-Varying Postprandial Increase in Splanchnic Blood Flow into a PBPK Model to Predict the Effect of Food on the Pharmacokinetics of Orally Administered High-Extraction Drugs

An impairment of gluconeogenesis has been proposed to explain the low arterial blood glucose of highlanders. Therefore, we studied splanchnic blood flow, splanchnic uptake of oxygen and lactate, and output of glucose in nine normal and six anemic highlanders at an altitude of 3,750 m. Splanchnic blood flow, arteriovenous difference for oxygen, and oxygen consumption were comparable at rest in both groups and in lowlanders from the literature, whereas splanchnic output of glucose, and uptake of lactate were approximately twice those in lowlanders. After 10 min of mild exercise in 12 subjects (7 normals, 5 anemic), no significant changes in splanchnic hemodynamics and metabolism were found. During 29% oxygen breathing in 8 subjects (5 normals, 3 anemics), arterial lactate, splanchnic uptake of lactate and output of glucose fell to normal sea-level values. We concluded that splanchnic hemodynamics are similar in adapted highlanders and in lowlanders, and that there is no evidence of an impaired gluconeogenesis at the altitude of the present study.

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Splanchnic Blood Flow in Experimental Shock

Advances in Experimental Medicine and Biology - The Fundamental Mechanisms of Shock ◽

10.1007/978-1-4615-9014-9_10 ◽

1972 ◽

pp. 87-107 ◽

Cited By ~ 4

Author(s):

Kenneth G. Swan ◽

Randall W. Barton ◽

David G. Reynolds

Keyword(s):

Blood Flow ◽

Splanchnic Blood Flow ◽

Experimental Shock

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Detection of 3rd mechanism in renal blood flow via high‐resolution, time‐varying spectral analysis of records subjected to chirp forcing of blood pressure

The FASEB Journal ◽

10.1096/fasebj.22.1_supplement.761.15 ◽

2008 ◽

Vol 22 (S1) ◽

Author(s):

Kin Siu ◽

Catherine Lau ◽

William Cupples ◽

Ki Chon

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Spectral Analysis ◽

High Resolution ◽

Renal Blood Flow ◽

Time Varying ◽

Resolution Time

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Effect of Xenon-Induced Flow Activation on Xenon-Enhanced Computed Tomography Cerebral Blood Flow Calculations

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-199811000-00005 ◽

1998 ◽

Vol 18 (11) ◽

pp. 1192-1195 ◽

Cited By ~ 21

Author(s):

Walter D. Obrist ◽

Zihong Zhang ◽

Howard Yonas

Keyword(s):

Computed Tomography ◽

Blood Flow ◽

Blood Velocity ◽

Time Varying ◽

Standard Analysis ◽

Stable Xenon ◽

Flow Activation ◽

Induced Flow ◽

Minimal Bias ◽

Enhanced Computed Tomography

Computer simulations of stable xenon (sXe) uptake curves were used to evaluate the effect of xenon-induced flow activation on CBF calculations by xenon-enhanced computed tomography, Estimates of flow activation were based on repeated transcranial Doppler measurements of blood velocity during 4,5 minutes of sXe inhalation, The synthetic curves were generated from a generalized Kety equation that included time-varying blood flow activation, In contrast to the peak 35% increase in blood flow velocity during sXe inhalation, a standard analysis of the flow-varying synthetic curves revealed only minor 3% to 5% increases in calculated CBF. It is concluded that brief xenon inhalations can provide blood flow estimates that contain minimal bias from activation.

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