Abstract

The energy sources of Trichinella spiralis change in both the muscular and intestinal stages of its life in the host organism. The purpose of this study was to investigate the quantitative changes in glycogen concentration during the life cycle of T. spiralis in a host organism. Trichinella spiralis was passaged on laboratory rodents under the vivarium conditions. Sixty-nine white rats (350 g each) were infected with T. spiralis at a dose of 5 muscle larvae/gram of body weight. The animals were euthanized at different time periods from the start of the experiment. Trichinella muscle larvae were isolated by artificial fermenting meat mince in gastric juice. To determine the viability of Trichinella larvae, they were heated to 38 ± 2 ° C for 10 minutes their motor activity was investigated. (38 ± 2 °C). To determine the invasive properties of T. spiralis at different stages of its development in rats, the muscular larvae isolated from the rat muscles were used to infect laboratory mice. The invasive capacity of T. spiralis was assessed on day 45 post-infection. For the study of intestinal Trichinella larvae, laboratory rats were not fed a day before infection. Adult nematodes were isolated from the small intestine of laboratory rats at 3, 6 and 24 hours post-infection. The nematodes were counted in the Migacheva-Kotelnikov chamber in each individual sample. The concentration of glycogen in the nematodes was calculated according to the quantitative method for determining glycogen in Trichinella larvae. Low glycogen levels in the muscle larvae were observed on day 14 post-infection. The glycogen concentration in muscular larva was 0.0054 ± 0.0027 μg/ larva on day 21, 0.0136 ± 0.0024 μg/ larva on day 28, and 0.0771 ± 0.0025 μg/ larva on day 45 after the rats were infected. Maximum concentration of glycogen was recorded 4 months post-infection (0.0930 ± 0.0029 μg/larva). Further, the glycogen level began to decrease slowly. In the 20th month post-infection, after infection, the amount of glycogen in a Trichinella larva was 0.0786 ± 0.0023 μg. In the body of intestinal nematodes, 3 hours after infecting the animals, the glycogen concentration was reduced to 0.0472 ± 0.0003 μg in one nematode. The same time period later, it reached to value of 0.0272 ± 0.0002 μg. In intestinal T. spiralis, which remained in the small intestine of rats for 24 hours, the glycogen was not detected. The amount of glycogen at the muscle stage of T. spiralis development was extremely important in the first hours of the helminth’s residing in the host's intestines. Energy requirements during the period when the helminth cannot obtain enough food depend on the glycogen content. When the glycogen concentration in the parasite is insufficient, the Trichinella larvae will lose their invasion capacity.