Developmental Physiology of Cestodes. II. Effects of Changes in Host Dietary Carbohydrate and Roughage on Previously Established Hymenolepis diminuta

Publisher Website
Google Scholar
Abstract
The effects of changes in host dietary carbohydrate and roughage on previously adult Hymenolepis diminuta were examined. In one experiment rat hosts were infected with five cysticercoids each, maintained on Purina Laboratory Chow (pellet ration) for from 21 to 28 days, then divided into treatment groups as follows: (1) continued feeding pellet ration, (2) fed a diet containing 30% starch as carbohydrate component, (3) fed a diet containing 30% sucrose, and (4) fed a carbohydrate-free diet. Worms from hosts on sucrose and carbohydrate-free diets rapidly decrease in weight, numbers of gravid and mature proglottids, and carbohydrate concentration. Lipid accumulates to high concentrations, and nitrogen rises slightly, but after a week nitrogen drops back to levels in the pellet and starch groups. Worms from rats on sucrose and carbohydrate-free diets have defective female reproductive systems, apparent from histopathology in late mature and gravid proglottids. In other experiments rats were infected and maintained as above, then changed from pellet ration to diets containing 30% cellulose, 5% cellulose, or no roughage. After 6 to 7 days worms from the high roughage diets are smaller, have lower lipid concentrations, and have slightly higher carbohydrate concentrations than worms from hosts on pellet rations, low roughage or roughage-free diets. Possible explanations for the observed effects are discussed in the light of pertinent knowledge of host-intestinal physiology.