Pancreatoduodenectomy as a source of human small intestine for Ussing chamber investigations and comparative studies with rat tissue

Abstract

A clear understanding of oral drug absorption is an important aspect of the drug development process. The permeability of drug co mpounds across intact sections of small intestine from numerous species, including man, has often been investigated using modified Ussing chambers. The maintenance of viable, intact tissue is critical to the success of this technique. This study therefore aimed to assess the viability and integrity of tissue from patients undergoing pancreatoduodenectomy, for use in cross‐species Ussing chamber studies. Electrical parameters (potential difference, mV; short‐circuit current, µA.cm−2; resistance, Ω.cm2) were monitored over the duration of each experiment, as was the permeability of the paracellular marker atenolol. The permeability values (Papp; cm/s × 10−6) for a training‐set of compounds, displaying a broad range of physicochemical properties and known human fraction absorbed values, were determined in both rat and human jejunum, as well as Caco‐2 cell monolayers. The results indicate that human jejunum sourced from pancreatoduodenectomy remained viable and intact for the duration of experiments. Permeability values generated in rat and human jejunum correlate well (R2 = 0.86), however the relationship between permeability in human tissue and Caco‐2 cells was comparatively weak (R2 = 0.58). Relating permeability to known human fraction absorbed (hFabs) values results in a remarkably similar relationship to both rat and human jejunum Papp values.It can be concluded that human jejunum sourced from pancreatoduodenectomy is a suitable source of tissue for Ussing chamber permeability investigations. The relationship between permeability and hFabs is comparable to results reported using alternative test compounds. Copyright © 2011 John Wiley & Sons, Ltd.

Prediction of Oral Absorption of Nanoparticles from Biorelevant Matrices Using a Combination of Physiologically Relevant In Vitro and Ex Vivo Models

“…Often, permeability studies are combined with metabolism studies to allow prediction of human oral bioavailability. As described above, there are numerous different in vitro and in vivo methods to determine intestinal permeability, which can be a good predictor of the fraction absorbed in humans for a specific set of compounds [11][12][13][44][45][46]. In addition, there are different intestinal metabolism methods (e.g.…”

“…Previous studies with ex vivo human intestinal tissue have shown that for pharmaceutical compounds the apparent permeability measured ex vivo is a good predictor of the fraction absorbed in vivo [11][12][13]. This suggests that ex vivo human intestinal tissue could also be used to study the permeability of NPs to indicate whether oral absorption of NPs is to be expected in vivo.…”

Ussing Chamber

“…Previous studies by Haslam et al (2011), Rozehnal et al (2012 and Sjöberg et al (2013) have shown that the intestinal tissue remains viable only for up to 150 min (on average 120 min), which is long enough to study absorption and/or secretion of satiety hormones. For the investigation of the impact of food bioactives on other health effects 2 h may be too short for any clear response, such as release of cytokines, reversible disruption of tight junctions, extensive metabolism.…”

“…Previous studies by Haslam et al (2011), Rozehnal et al (2012 and Sjöberg et al (2013) have used the potential difference (>4 mV), short-circuit current (>100 μA/cm 2 ), trans epithelial electrical resistance (TEER; >20 Ω cm 2 ) for continuous monitoring of the viability. Low resistance indicates tissue leakage.…”

“…Other markers that can be studied in parallel to a typical transport study include the intestinal metabolism of testosterone and midazolam, by measuring the presence of metabolites apically, basolaterally and intracellularly by means of, for instance, High Pressure Liquid Chromatography (HPLC) (Sjöberg et al 2013). Transport via the paracellular pathway can be assessed by measuring the permeability of Lucifer yellow (Papp value <6 × 10 −6 cm/s) (Rozehnal et al 2012) leakage of fluorescein isothiocyanate dextran to the basolateral side (FD4; <0.5 %) , or the linearity of transport of atenolol (R 2 > 0.995 with at least 3 datapoints) (Haslam et al 2011). Values higher than the ones mentioned above, indicate leakage of the intestinal tissue.…”