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TEER is an epithelial assay measure, not a direct clinical permeability score.\nexposure: Enteroid NHE3 perturbation; healthy volunteers 15 mg tenapanor twice daily for four days\nevidence_span: {\"source_cache\": \"artifacts/phosphorus-research/30158152.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"6e6950931f538331a62ce1a6b35ba66ddf0a6bcaec7fe4b4f8f81e8fd952ee0e\", \"start_char\": 0, \"end_char\": 1701, \"text_sha256\": \"6e6950931f538331a62ce1a6b35ba66ddf0a6bcaec7fe4b4f8f81e8fd952ee0e\"}\n[phosphorus-p30158152] Inhibition of sodium/hydrogen exchanger 3 in the gastrointestinal tract by tenapanor reduces paracellular phosphate permeability. 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