Características morfológicas de vermes adultos machos e fêmeas de Schistosoma mansoni recuperados de camundongos desnutridos e deficientes em óxido nítrico

Abstract

Schistosomiasis and malnutrition are both serious public health concerns in developing countries. Schistosoma infection causes a range of morbidities, which is influenced to a large extent by the nature of the induced immune response and the nutritional status of the host. During the schistosomiasis infection, the immune response produces cytokines which are released by stimulating production of nitric oxide. Numerous studies have demonstrated that the nutritional status and the immune response affect the phenotypic characteristics of the adult worms. However, whether nitric oxide plays a role is unknown. In this study, wild type mice (control group) and Knockout mice deficient in nitric oxide production either fed a commercial diet (UNILAB) or a regional basic diet with low protein diet (7.87%). By means of a digital system for image analysis (Image Pro Plus, USA) and confocal microscopy, we studied the morphology of the oral sucker, tegument and reproductive system of male and female worms. Malnourished male and female worms showed sloughing of the tegument. The dorsal surface of male malnourished worms presented irregular tubercles, unevenly distributed, and scarce. The reproductive system of female worms malnourished showed no morphological changes. The reproductive system of malnourished female worms did not show morphological changes. However, male worms from this group displayed smaller number of cells in differentiation process within the testicular lobes. In conclusion, our results suggest that the deficiency of nitric oxide does not induce morphological changes at the level of the integument and the reproductive system of male worms. In contrast, malnutrition is responsible by such morphological changes, mainly in the reproductive system and oral sucker.