The growth of Moniliformis dubius (Acanthocephala) in the intestine of male rats.

The helminth Moniliformis dubius forms a convenient source of material for studying the biochemistry and physiology of acanthocephalans because it grows to a relatively large size and its life-cycle is easily maintained in the laboratory. The parasite develops in the haemocoele of the cockroach Periplaneta americana and sexual maturity is achieved in the small intestine of rats. Biochemical work on helminths, however, will progress slowly until the worms in question have been cultured in vitro. One difficulty with culture work is the selection of a trustworthy means of assessing growth. Measurements of the lengths and wet weights are unreliable, and the aim of the work described below was to measure the protein nitrogen, the DNA and the RNA content of M. dubius during the course of its infection in rats. These results could then be "used to monitor the growth of worms being kept in vitro and to form the basis for experimental studies of their growth in vivo.