Submitted to: Toxicon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2005
Publication Date: 4/7/2006
Citation: Barbosa, R.C., Riet-Correa, F., Medeiros, R.M., Lima, E.F., Barros, S.S., Gimeno, E.J., Molyneux, R.J., Gardner, D.R. 2006. Intoxication by ipomoea sericophylla and ipomoea riedelii in goats in the state of paraiba, northeastern brazil. Toxicon.
Interpretive Summary: A nervous system disease was observed in goats from certain farms in northeastern Brazil. Clinical signs of intoxication included rough hair coat, depression, weight loss, and nervous signs including difficulties in rising, ataxia, hypermetria, wide stance, tremors, spastic paresis in hind legs, nystagmus, and head tilting. During the rainy seasons it was noticed that some paddocks were invaded by species of Ipomoea. Plant samples were collected from two farms with noted cases of poisoned goats and the plants were identified has Ipomoea sericophylla and I. riedelii. Plant material was fed under experimental conditions to goats which developed clinical signs identical to field observed animals. Complete histological and ultrastructural findings were documented and describe for intoxicated animals. The histological examination of tissues indicated lysosomal storage disease consistent with poisoning by other Ipomoea, Swainsona, Oxytropis, Astragalus species with contain the toxin swainsonine. Chemical analysis of the plant material found high levels of swainsonine in both plants, and in addition, I. riedelii also contained calystegines which also known glucosidase inhibitors.
Technical Abstract: A disease of the nervous system was observed in goats from two farms of the semiarid of the state of Paraiba, northeastern Brazil. Ipomoea sericophylla was found in one farm and I. riedelii in the other. Both plants were administered experimentally to five goats each. Both plants induced clinical signs similar to those observed in spontaneous cases. Two goats died spontaneously and five were euthanatized. Three goats recovered after the withdrawal of the plants. Histological examination showed that all goats that died spontaneously or were euthanized had diffuse vacuolation of neurons, macrophages of lymphatic tissues, and epithelial cells of pancreas, thyroid, renal tubules and liver. On electron microscopy of Purkinje cells, numerous dilated membrane bordered vacuoles were identified as lysosomes. On lectin-histochemical analysis, cerebellar cells gave positive reactions to Concanavalia ensiformis, Triticum vulgaris, and succinylated-T. vulgaris, which indicate the storage of '-D-mannose, '-D-glucose, '-D-N-accetyl-glucosamine, and acetyl-neuraminic acid. The chemical analysis of I. sericophylla and I. riedelii showed 0.11 and 0.14% of swainsonine, respectively. The latter also contained calystegines B1, B2 and C1. It is concluded that I. sericophylla and I. riedelli cause a lysosomal storage disease.