3‐Hydroxypropylmercapturic acid: A biologic marker of exposure to allylic and related compounds

3‐Hydroxypropylmercapturic acid [3‐OHPrMCA, S‐(3‐hydroxypropyl)‐N‐acetyl‐‐l‐‐cysteine] was quantitatively measured by high‐performance liquid chromatography (HPLC) in the urine of rats given allylamine‐HCl (5, 25, 50, 100 and 150 mg kg⁻¹), acrolein (13 mg kg⁻¹), allylalcohol (64 mg kg⁻¹), allylchloride (76 mg kg⁻¹), allylbromide (120 mg kg⁻¹), allylcyanide (115 mg) and cyclophosphamide (160 mg kg⁻¹) by gavage in water. 3‐OHPrMCA was measured by HPLC in 24‐h urine collections; the lower detection limit was 1.25 μg or 5.6 nmol ml⁻¹. Various doses of allylamine resulted in 3‐OHPrMCA excretion at a fairly constant percentage of the dose, ca. 44–48% at 0–24 h and 3% at 24–48 h, indicating rapid metabolism through glutathione conjugation in the first 24h. Similarly, 3‐OHPrMCA was recovered in the urine of rats given acrolein (78.5%), allylalcohol (28.3%), allylchloride (21.5%), allylbromide (3.0%), allylcyanide (3.7%) and cyclophosphamide (2.6%). These data indicate that 3‐OHPrMCA can be used as a marker of exposure to allylic and other compounds that lead to the metabolic formation of acrolein.