Alpha-mannosidosis caused by toxic plants in ruminants of Argentina.

It is well known that several of the swainsonine-containing plant species found widespread around the world have a negative economic impact in each country. In Argentina, most of the information on the poisonous plant species that produce α-mannosidosis is published in Spanish and thus not available to most English-speaking researchers interested in toxic plants. Therefore, the aim of this review is to summarize the information about swainsonine-containing plants in Argentina, which are extensively distributed throughout different ecoregions of the country. To date, five species from three genera have been shown to induce α-mannosidosis in livestock in Argentina: Ipomoea carnea subsp. fistulosa, Ipomoea hieronymi subsp. calchaquina (Convolvulaceae), Astragalus garbancillo, Astragalus pehuenches (Fabaceae), and Sida rodrigoi (Malvaceae). These species contain the indolizidine alkaloid swainsonine, which inhibits the lysosomal enzyme α-mannosidase and consequently affects glycoprotein metabolism, resulting in partially metabolized sugars. The prolonged consumption of these poisonous plants produces progressive weight loss and clinical signs related to a nervous disorder, characterized by tremors of head and neck, abnormalities of gait, difficulty in standing, ataxia and wide-based stance. Histological lesions are mainly characterized by vacuolation of different cells, especially neurons of the central nervous system. The main animal model used to study α-mannosidosis is the guinea pig because, when experimentally poisoned, it exhibits many of the characteristics of naturally intoxicated livestock.

Haematologic alterations caused by Ipomoea carnea in experimental poisoning of guinea pig.

Ipomoea carnea subsp. fistulosa (Convolvulaceae) causes poisoning of goats, sheep and cattle in many tropical and subtropical countries. The pathophysiology of this poisoning mainly involves an abnormal glycoprotein metabolism. The aim of this study was to describe the potential toxicity of I. carnea in a guinea pig model through its effect on hematopoiesis in a time course study of 40 days. Experimental poisoning was achieved by feeding animals with "small balls" prepared with milled leaves of I. carnea mixed with commercial crushed pellets for rodents. Hematologic and biochemical parameters, bone marrow and spleencellularities, histopathologic evaluations and lectin-histochemistrywere performed during the scheduled time of the study.The treatment with "small balls" caused significant changes in the weight of spleen, a notable decrease in peripheral red blood cells, and concomitantwith morphological and histopathologicalalterationsin hematopoietic tissues. Overall, the present study suggested that 20 days ofthis treatmentcouldbe enough to develop bone marrow hypoplasia and vacuolation of white cells of spleen, blood and lymph nodes with a transient erythropoietic contribution of the splenic niche.Moreover, this work provides a cheap and simple method for detecting preclinical cases of intoxication by I. carnea in livestock.

Suspected natural lysosomal storage disease from ingestion of pink morning glory (Ipomoea carnea) in goats in northern Argentina.

This study describes an occurrence of pink morning glory (Ipomoea carnea) intoxication in goats in northern Argentina. The clinical signs displayed by the affected animals were ataxia, lethargy, emaciation, hypertonia of the neck muscles, spastic paresis in the hind legs, abnormal postural reactions and death. The clinico-pathologic examination revealed that the affected animals were anemic and their serum level of aspartate aminotransferase was significantly increased. Cytoplasmic vacuolation in the Purkinje cells and pancreatic acinar cells was observed by histological examination. The neuronal lectin binding pattern showed a strong positive reaction to WGA (Triticum vulgaris), sWGA (succinylated T. vulgaris) and LCA (Lens culinaris). Although I. carnea is common in tropical regions, this is the first report of spontaneous poisoning in goats in Argentina.