p-Aminobenzoic acid as an alternative chemical biopsy agent for human hepatic UDP-glucose

p-Aminobenzoic acid (PABA) was evaluated for noninvasive sampling of UDP-glucose in the liver. Six healthy subjects ingested 550 mg PABA during a breakfast meal. Urine was collected 0–2 and 2–4 h after PABA ingestion. N-acetyl PABA glucuronide (NAPG) was identified with 522 ± 212 μmol recovered in the 2–4 h urines. One of the subjects ingested 2 g of 98% [U–2H7]glucose alongside PABA and the NAPG was analyzed for positional 2H-enrichment by 2H...