Metabolism of C(14)-glucose by Ascaridia galli

Abstract

The fowl nematode Ascaridia galli employed in this experiment was obtained from the intestine of domestic fowls at the local market. The worms selected and washed several times in normal sterilized saline solution. Each about thirty of intact worms were incubated in 50 cc volume of special incubation flasks with incubation mixture consisting of 10 cc of Krebs-Ringer phosphate buffer (pH 7.4) to which were added universally labeled C14-glucose and non-radioactive carrier glucose so as to contain concentration of 200 mg per cent. The worms were allowed to incubation for 3 hours in Dubnoff metabolic shaking incubator at 38 degrees C. After incubation period, respiratory CO2 samples from central well of incubation flask were analysed for total CO2 production rate and their specific activity of respiratory CO2. Glycogen samples isolated from worms were analysed for uptake rate was determined by analyzing the difference of the glucose concentration in a medium before and after incubation period. Radioactivities of these series of experiments were counted by an endwindow Geiger-Muller counter as an infinitely thin samples. The quantitative analysis of C(14)-glucose utilized by Ascaridia galli was summarized as the following. 1. The glucose uptake rate by A. galli was a mean value of 1.73 +/- 0.32 micro M/hr/g of wet wt. and total CO2 production rate by the worms averaged 8.44 +/- 1.11 micro M/hr/g of wet wt. The relative specific activity of respiratory CO2 (R.S.A CO2) averaged 2.68 +/- 0.38 per cent. Thus, a man of 2.68 per cent of total CO2 production rate was originated from the glucose in the medium, therefore the rate of CO2 production derived from medium glucose was a mean of 0.23 +/- 0.03 micro M/hr/g of wet wt. Thus, the average value of 2.58 +/- 0.55 percent (R.G.D CO2)of glucose utilized by the worms from the medium glucose was oxidized to respiratory CO2. 2. The tissue concentration of glycogen in A. galli was a mean of 22.59 +/- 1.18 mg per gram of wet wt or 2.26 +/- 0.123 percent per gram, and the turnover rate of glycogen pool yielded with a mean of 0.17 +/- 0.04 percent per hour or 0.037 +/- 0.006 miligram per hour per gram of wet wt. Therefore, a mean value of 16.37 +/- 4.04 per cent (R.G.D gly) of glucose was incorporated to the glycogen. 3. These data account for that at least 18.95 per cent of the utilized glucose by the worms participated in furnishing the oxidation into respiratory CO2 and the synthetic process into glycogen. According to the above data of the experiment, it is suggested in the metabolic process of glucose by Ascaridia galli that the synthetic process into the glycogen is more active than the oxidative process into the respiratory CO2.