Moniliformis dubius and Macracanthorhynchus hirudinaceus: Na, K, Ca, and Mg Content, and Na and K active transport

Abstract

Moniformis dubius and Macracanthorhynchus hirudinaceus : Na, K, Ca, and Mg Content, and Na and K active transport. Experimental Parasitology 27 , 33–43. The Na, K, Ca, and Mg content of M. dubius and the Na and K content of M. hirudinaceus have been determined. It is shown that both sexes of M. dubius maintain a higher concentration of K and a lower concentration of, Na than the rat intestine. This finding was taken as evidence of active transport of these ions. The real osmotic pressure these ions would exert in M. dubius was estimated together with the total osmotic balance of the parasite and the rat intestine contents. The parasite is hyperosmotic to its environment. The distribution of Na, K, and Cl ions was histochemically determined. Defined bands of ions were found, suggesting that some are bound in fixed locations. Studies of the movement of Na and K using the radioisotopes 24 Na and 42 K showed that a proportion of these ions is not exchanged in vitro . When the exchangeable internal concentration of Na and K was estimated the parasite was found to be isoosmotic with the rat intestine. The ability of M. dubius to transport both Na and K against a chemical gradient was also demonstrated.