Plerocercoid Infection Research Articles

Effects of spirometrid plerocercoids on several species of lower vertebrates

1. 1. The effects of the plerocercoid growth factor on several species of lower vertebrates were tested. 2. 2. There was little effect on growth or fattening in either fish or frogs. 3. 3. Plerocercoid infections and to a lesser degree worm homogenate injections markedly stimulated growth but not fattening in lizards.

Effects of age on growth and food efficiency response in rats infected with tapeworm larvae.

Several groups of investigators (1-3) have shown that the growth rates of young rapidly growing rats cannot be increased by infection with plerocercoids of the tapeworm Spirometra mansonoides. However, Steelman et al. (4) showed that adult female rats respond to plerocercoid infection with a body weight gain similar to that produced by growth hormone (GH). Glitzer and Steelman (2) also observed a marked decrease in pituitary weight (37%) and in plasma GH levels from control values of 27 ng/ml to nondetectable levels at 10 days following worm infection. These observations have been confirmed by Garland and Daughaday (5).Steelman and Morgan (6) infected 22 day old castrated male rats with plerocercoids and observed a body weight increase similar to that obtained with GH. No effect was observed on the seminal vesicle and prostate weights but when worm-infected animals were supplemented with methyl testosterone a striking potentiation of the seminal vesicle and prostate weights resulted. These studies point t...