Glycogen Content and In Vitro Glycogen Consumption in Sheep Cestode Moniezia expansa (Rudolphi, 1805)

Abstract

Moniezia expansa is common cestode in the small  intestine of sheep and causes considerable damage to  it. Therefore, an effort to study such biological aspects  of Moniezia expansa which would help in its control is much needed. The glycogen content and in vitro consumption of endogenous glycogen was determined  in immature, mature and gravid proglottids of  Moniezia expansa by Anthrone method by Carroll et al. (1956). The total glycogen (on fresh weight basis) was  found to be 3.03%, 4.26% and 3.85% respectively in  immature, mature and gravid proglottids of unstarved  (control) parasite. The glycogen content in immature,  mature and gravid proglottids of parasites starved for  3 hrs. is 2.51%, 3.09% and 2.91% respectively, parasites  starved for 6 hrs is 1.91%, 2.0% and 2.0% respectively,  parasites starved for 9 hrs. 1.25%, 1.33% and 1.35  respectively and parasites starved for 12 hrs is 0.79%,  0.80% and 0.99% respectively (on fresh weight  basis).The endogenous glycogen consumption (in  percent of total glycogen content of control parasite) by  immature, mature and gravid proglottid was found to  be 17.16%, 27.46% 24.42% respectively in parasites  starved for 3 hours, 36.96%, 53.05% and 48.05%  respectively in parasites starved for 6 hours, 58.75%  68.78% and 64.94% respectively in parasites starved for  9 hours and 73.93%, 81.22% and 74.29% respectively in  parasites starved for 12 hours. Rate of consumption of  endogenous glycogen between different starvation  time periods (in percentage per hour) for immature, mature and gravid proglottids is also calculated. Rate  of consumption was maximum during early hours of  starvation i.e. between 0-3 hrs and 3-6 hrs and was  minimum at 9-12 hrs. Glycogen is the major energy  reserve in parasitic helminths which live in low oxygen  condition, as they are the best substrate for anaerobic  energy production. The study of consumption of  endogenous glycogen in cestode during starvation  period may be quite helpful for their control in the  host. The rate of endogenous glycogen consumption is  helpful in understanding metabolic rate and  physiological aspects of different proglottids of the  parasite.