Glycogen content in Moniliformis dubius (Acanthocephala).

Glycogen has been quantitated in Moniliformis dubius from male and female rats. It was found that male worms contained more glycogen per unit weight than female worms. This was true regardless of the sex of the host. Worms recovered from female rats were smaller than worms in the male rats. Female worms, although smaller in the female rat, contained more glycogen per unit weight than female worms from male rats. A single sex infection consisting of only male worms was accidentally obtained in a group of male rats. These worms were larger and contained more glycogen than worms from the control infection. These results suggest that there are two independent phenomena affecting worm growth and metabolism. One is the interaction of male and female worms in a single infection. The other is the effect of the endocrine system of the host on worm development and metabolism. Read (1961) reviewed the literature pertaining to carbohydrate metabolism in parasitic helminths. In recent years there has been a considerable number of investigations on this subject, especially on the cestodes. Information on carbohydrate metabolism in the Acanthocephala is still rather limited. Read and Rothman (1958) investigated the carbohydrate requirements of Moniliformis dubius. They found that normal growth of this worm was dependent on the presence of carbohydrate in the host diet. They further reported that the glycogen levels in M. dubius showed a diurnal fluctuation which was correlated with the feeding time of the host. The glycogen content in M. dubius was also affected by the type of carbohydrate in the host diet. We have carried out additional quantitative studies of the glycogen content in M. dubius. The results show that other variables besides diet and feeding time of the host influence the quantity of glycogen in this worm. MATERIALS AND METHODS Male and female Sprague-Dawley rats, 3 months old at time of infection, were used as hosts. Cystacanths of M. dubius were obtained from laboratory-infected roaches. Each rat was infected with 20 cystacanths by the method of Moore (1946). Unless stated otherwise, the worms used in this study were collected 39 days after infection. Infected rats were starved 24 hr prior to autopsy. This starvation time was selected in an attempt to insure a standardized level of endogenous carbohydrate in Moniliformis. The rats were killed by a sharp blow on the head. The worms were then washed in Ringer's solution, blotted on filter paper, and weighed on a torsion balance. They were then used for glycogen analysis. The rats used in this study were housed in cages 18 by 24 by 10 inches. Each cage contained 12 animals. A vertical feeding tray and two water bottles were provided for each cage. The rats were allowed to feed ad libitum. Under these conditions the recovery of adult worms from a 20cystacanth infection averaged about 70% (49% to 100%). This recovery agreed with that reported by Burlingame and Chandler (1941) for M. dubius during a 39-day infection period. Glycogen was determined by the method of Carroll et al. (1956). The worms were homogenized in 5% trichloroacetic acid, and the homogenate was centrifuged. Glycogen was precipitated from the supernatant by the addition of ethanol to a final concentration of 70%. The resulting precipitate was collected by centrifugation, washed in 70% ethanol, and recentrifuged. The precipitate was then dissolved in water to a desired volume. Aliquots were analyzed for carbohydrate by use of the anthrone reagent of Roe (1955). The color was measured on a Coleman Junior Spectrophotometer at 620 mjz. Appropriate mean values for worm weight and glycogen content were compared by Student's t test. The t values are given in the text. Differences between means were considered significant when P < 0.05. Received for publication 24 October 1962. * This work was supported by National Institutes of Health Training Grant No. 2E-70 and University of California Faculty Research Grant No. 1718 (Zoology). 204 This content downloaded from 157.55.39.249 on Wed, 03 Aug 2016 06:01:54 UTC All use subject to http://about.jstor.org/terms GRAFF AND ALLEN-GLYCOGEN IN MONILIFORMIS 205 TABLE I. Wet weight and glycogen content of Moniliformis dubius from male rats.