TROPANE ALKALOIDS AND TOXICITY OF CONVOLVULUS-ARVENSIS

Horses in a few, localized northern Colorado pastures exhibited weight loss and colic. At post mortem, intestinal fibrosis and vascular scle rosis of the small intestine was identified. The pastures where the af fected horses grazed were overrun by field bindweed (Convolvulus arven sis). Bindweed from the pasture was found to contain the tropane alkal oids tropine, pseudotropine, and tropinone and the pyrrolidine alkaloi ds cuscohygrine and hygrine. Laboratory mice readily ate C. arvensis a nd exhibited a variety of abnormal clinical signs depending on the amo unt eaten. Similar alkaloids have been found in other Convolvulus spec ies and cuscohygrine and calystegines (poly-hydroxytropanes) have been previously reported from C. arvensis roots. This is the first report of simple tropane alkaloids in C.arvensis, a world wide problem weed. Pseudotropine, the major alkaloid, is known to affect motility and mig ht represent a causative agent for the observed cases of equine intest inal fibrosis.