Biophysical Model of the Transcuticular Excretion of Organic Acids, Cuticle pH and Buffer Capacity in Gastrointestinal Nematodes
作者:
SimsS. M.,
HoN. F. H.,
MagasL. T.,
GearyT. G.,
BarsuhnC. L.,
ThompsonD. P.,
期刊:
Journal of Drug Targeting
(Taylor Available online 1994)
卷期:
Volume 2,
issue 1
页码: 1-8
ISSN:1061-186X
年代: 1994
DOI:10.3109/10611869409015888
出版商: Taylor&Francis
关键词: Cuticle pH;Transcuticular organic acid excretion;Biophysical model;Ascaris suum;Chemical equilibrium
数据来源: Taylor
摘要:
AbstractA biophysical model was developed, usingAscaris suumas a model gastrointestinal nematode, to provide quantitative perspectives into the microenvironmental pH within the water-filled, porous, negatively charged cuticle matrix of gastrointestinal nematodes. The central features of the model include (a) the constant rate of excretion of organic acid metabolites across the cuticle, (b) the relationship between cuticle pH and pKaof the organic acids that determines the fraction of unionized and ionized species, and (c) the concentration gradient, mean concentration and buffer capacity within the cuticle that maintain the cuticle pH. The model may be used to predict the extent to which transcuticular absorption of weakly basic and acidic anthelmintics will be affected by transcuticular excretion of organic acid metabolites. Coupled with established models for drug absorption by nematodes and the host gastrointestinal tract, the cuticle pH model provides new insights to the design of drugs with physicochemical properties that favor absorption by nematodes.
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