OBJECTIVEIn order to investigate that ascorbic acid deficiency is responsible for lathyrus toxicity, the effect of dietary feeding of lathyrus pulse in normal and scorbutic guinea pigs for 3 months, on intestinal biochemical parameters was undertaken.

METHODSThe intestinal brush border membrane (BBM) marker and xenobiotic metabolising enzymes (XME) were assayed.

RESULTSExposure to 80% lathyrus alone and in scorbutic conditions showed significant inhibition of alkaline phosphatase (28%-30%), sucrase (19%) and gamma-glutamyl transpeptidase (GGT) (15%-27%) enzymes, while Ca(2+)-Mg(2+)-ATPase was significantly inhibited (38%) in scorbutic plus lathyrus treated group. The phase I XME (AHH) remained unchanged while the phase II enzyme glutathione-S-transferase (GST) was significantly decreased (20%-22%) in lathyrus and scorbutic plus lathyrus treated groups. Quinone reductase (QR) activity was found to be significantly decreased in lathyrus exposed group (20%). The intestinal biomarker contents including hexose (25%-34%) and phospholipids (20%-40%) were significantly reduced in lathyrus and scorbutic plus lathyrus exposed animals, while sialic acid showed a significant decrease (28%) in scorbutic plus lathyrus treated group. However, cholesterol levels were significantly enhanced (15%-28%) in lathyrus and scorbutic plus lathyrus treated animals.

CONCLUSIONThe results indicate that oral feeding of lathyrus pulse to guinea pigs can alter BBM parameters as well as XME, which may result in the intestinal toxicity. Further, ascorbic acid deficiency could be one of the pre-disposing factors of lathyrus toxicity.

Administration, Oral ; Animals ; Ascorbic Acid Deficiency ; complications ; veterinary ; Biomarkers ; analysis ; Cholesterol ; blood ; Diet ; Digestive System ; enzymology ; metabolism ; pathology ; Guinea Pigs ; Lathyrus ; chemistry ; Male ; Microvilli ; Phospholipids ; metabolism ; Plant Extracts ; adverse effects

Hyperoxic ventilation induces detrimental effects on the respiratory system, and ambient oxygen may be harmful unless compensated by physiological anti-oxidants, such as vitamin C. Here we investigate the changes in electrolyte transport of airway epithelium in mice exposed to normobaric hyperoxia and in gulonolacton oxidase knock-out (gulo[-/-]) mice without vitamin C (Vit-C) supplementation. Short-circuit current (Isc) of tracheal epithelium was measured using Ussing chamber technique. After confirming amiloride-sensitive Na+ absorption (DeltaIsc,amil), cAMP-dependent Cl- secretion (DeltaIsc,forsk) was induced by forskolin. To evaluate Ca2+-dependent Cl- secretion, ATP was applied to the luminal side (DeltaIsc,ATP). In mice exposed to 98% PO2 for 36 hr, DeltaIsc,forsk decreased, DeltaIsc,amil and DeltaIsc,ATP was not affected. In gulo(-/-) mice, both DeltaIsc,forsk and DeltaIsc,ATP decreased from three weeks after Vit-C deprivation, while both were unchanged with Vit-C supplementation. At the fourth week, tissue resistance and all electrolyte transport activities were decreased. An immunofluorescence study showed that the expression of cystic fibrosis conductance regulator (CFTR) was decreased in gulo(-/-) mice, whereas the expression of KCNQ1 K+ channel was preserved. Taken together, the CFTR-mediated Cl- secretion of airway epithelium is susceptible to oxidative stress, which suggests that supplementation of the antioxidant might be beneficial for the maintenance of airway surface liquid.
Animals ; Ascorbic Acid Deficiency/*metabolism ; Biological Transport/drug effects ; Chlorides/*metabolism ; Cystic Fibrosis Transmembrane Conductance Regulator/antagonists & inhibitors/drug ; Forskolin/pharmacology ; Hyperbaric Oxygenation ; Hyperoxia/*physiopathology ; Ion Transport/drug effects ; Mice ; Mice, Inbred C57BL ; Mice, Inbred ICR ; Mice, Knockout/metabolism ; Mice, Transgenic ; Microscopy, Fluorescence ; Oxidative Stress ; Oxygen/adverse effects/pharmacology ; Potassium Channels/metabolism ; Respiratory Mucosa/drug effects/*metabolism/secretion ; Sodium ; Sugar Acids/metabolism