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Network Thermodynamic Model of Coupled Transport in a Multicellular Tissue ‐ The Islet of Langerhans a
Author(s) -
FREITAS ROBSON C.,
DILLER KENNETH R.,
LACHENBRUCH CHARLES A.,
MERCHANT FATIMA A.
Publication year - 1998
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1998.tb10153.x
Subject(s) - dimethyl sulfoxide , chemistry , islet , osmotic dehydration , matrix (chemical analysis) , thermodynamics , biophysics , chromatography , mass transfer , insulin , biology , physics , organic chemistry , endocrinology
A bstract : Network thermodynamic modeling via bond graphs was used to describe the water and cryoprotectant additive (CPA) transport in a multicellular tissue. The model is presented as a tool to understand the osmotic behavior of the islets of Langerhans when exposed to ternary aqueous solutions containing an electrolyte and a CPA. It accounts for the effects of the location of cells within the tissue and an interstitial matrix, plus differential permeabilities to water and CPA. The interstitial matrix was assumed to be a porous medium able to store the chemical species being transported. Controlled osmotic stress experiments were conducted on isolated rat pancreas islets to measure the transient volumetric response to step‐wise changes in dimethyl sulfoxide, Me 2 SO, concentration. The model provides a tool for predicting the transient volumetric response of peripheral and interior cells and of interstitial tissue, as well as the build up of solute concentration, during addition and removal of CPAs and freezing and thawing protocols. Inverse solution methods were applied to determine values for standard cell memebrane permeability parameters L p , ω and σ as well as for the interstitial flow conductivities K w and K p ,.