Effect of dietary tetrapyrroles on gut pigmentation and perienteric fluid hemoglobin concentration in Ascaris lumbricoides

Ascaris lumbricoides was maintained for 46 days in three pigs fed diets enriched with different metalloporphyrins. Diets, host gut contents, and washed worm guts were differentially extracted for carotenoids, bile pigments, porphyrins and metalloporphyrins, and extracts were compared by spectrophotometric and qualitative chemical tests. Host gut contents from a control diet with no added porphyrin contained carotenoids and bilirubin; worms from this host contained bilirubin and an unidentified metalloporphyrin. An alfalfa-enriched diet yielded phaeophytin A in host gut contents, while worm gut tissue contained an unidentified metalloporphyrin different from the controls. Host gut contents and worms from a blood meal-enriched diet both contained protoheme IX; perienteric fluid concentration in these worms (0·211 mM) was five times that of the other groups. The presence of metalloporphyrins in guts of worms reared on linear tetrapyrroles suggests the ability to convert these compounds to heme.