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Influence of the lead on the biology of Nippostrongylus brasiliensis was examined. N. brasiliensis larvae exposed to the action of 200 ppm lead during 9 days were used to infect rats. The first group of the rats were infected with 1000 larvae kept in the solution of PBS whereas the larvae contaminated with the lead were given to the second group of rats. Capability to invasion of the contaminated larvae decreased by 28.7-57,2%. Reproductiveness of the N. brasiliensis decreased by 40.6% and the maximum point of production of the eggs was moved back by one day.
It was investigated whether toxicity of lead (Pb) is so high that its effect on Nippostrongylus brasiliensis larvae could be transferred into subsequent (3) generations of the nematode. Wistar rats were infected with a dose 1000 N. brasiliensis larvae contaminated with Pb (9 days at 200 ppm in solution). The number of larvae in lungs after 24 and 42 hours and the number of adult nematodes in the small intestine after 90, 114 and 236 hours after infection were examined. To determine reproductiveness of the N. brasiliensis the number of eggs was determined. Eggs of the first generation subjected to Pb (P generation) were used to culture a subsequent generation of invasive larvae (F₁) which were used to infect rats. Eggs from that generation were used to culture the next invasive larvae generation (F₂) used again to infect rats. Lungs dissection after 24 hours has shown that the P generation produced 12 times less larvae than the control, while generations F₁ and F₂ produced 4,9-5 times less larvae than the control. Dissection data for the small intestine show the highest loss in invasive capability of this nematode in generation F₁. The dynamics of eggs excretion is the lowest in F₁ and excretion period is shorter by 1 day. In F₂, the number of eggs excreted is 5.8 times higher than in the control group. It seems that in F₂ generation mechanisms enabling the species to survive under unfavorable environmental conditions were started.
The aim of this study was to determine the action of zinc, cooper, lead and cadmium compounds upon N. brasiliensis invasive nematode larvae. The tested larvae were kept in ZnCl2, CuCl2 , Pb(NO3)2 and CdCl2 solutions. The concentrations of toxic substances applied for the study corresponded with level of environmental pollulion. All toxins reduced live - space of larvae. In control group they survived about 69 days. In solutions of the Zn, contaminated with 10, 50, 100 and 200 ppm of toxic substance, they survived 42, 16, 14 days and 72 hours. In solution of Cu, contaminated with 5, 10, 50 and 200 ppm of toxin, live - space was reduced to 51, 21, 7 days and 54 hours, respectively. Lead reduced live - space of larvae to 26 days already at the low concentration of 10 ppm and in all higher concentrations (20, 50 and 200 ppm) their survival changed unsignificantly (to 22 days). In solution of Cd, contaminated with 0.1 and 0.3 ppm larvae died after 39 and 17 days, respectively, white at higher concentrations of this toxin (3 and 10 ppm) larvae survived only 54 and 30 hours, respectively.
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