Doença de depósito lisossomal provocada pelo consumo de Ipomoea verbascoidea (Convolvulaceae) em caprinos em Pernambuco

Abstract

The aim of this paper is to describe the epidemiological, clinical and histopathological aspects of poisoning by Ipomoea verbascoidea in goats in Pernambuco, northeastern Brazil and reproduce experimentally the disease in goats. For this, we carried out the monitoring of the epidemiology of the disease in seven municipalities in the semiarid region of Pernambuco. Three spontaneously intoxicated goats were examined and then euthanized and necropsied (Group I). For the disease reproduction, the dried leaves of I. verbascoidea containing 0.02% swainsonine was supplied at doses of 4g/kg (80mg swainsonine/kg) for two groups of three animals. The goats in Group II received daily doses of the plant for 40 days and were euthanized on the 41st day of the experiment. Goats from Group III received daily doses of the plant during 55 days and were euthanized on the 120th day of the experiment. Other three goats constituted the control group (CG). In all groups cerebellar lesions were evaluated morphometrically; for this the molecular layer of the cerebellum and the Purkinje neurons area were measured. The main clinical signs and microscopic lesions in goats spontaneously poisoned were similar to those reported by swainsonine containing plants. In experimental goats (GII and GIII), the first nervous signals were observed between 22 and 27 days; clinically, the disease developed by these animals was similar to the spontaneous cases. The goats of GIII did not recover from the nervous picture. These results indicate that irreversible damage occurs when the goats continue ingesting the plant for more than 30 days after the observation of first clinical signs. In goats experimentally poisoned the lesions consisted of various degrees of neuronal cytoplasmic vacuolation in the cerebellum, basal ganglia, bulb at the height of the obex and telencephalon. By morphometric analysis, the molecular layer of the cerebellum of goats of Group I and III were thinner than goats of control group and the Purkinje neurons of goats were atrophic. These results demonstrate the irreversibility of the neuronal picture.