Hostname: page-component-77c89778f8-m8s7h Total loading time: 0 Render date: 2024-07-19T04:23:42.898Z Has data issue: false hasContentIssue false

The influence of dietary methionine on the amino acid pool of Hymenolepis diminuta in the rat's intestine

Published online by Cambridge University Press:  06 April 2009

C. A. Hopkins
Affiliation:
Wellcome Laboratories for Experimental Parasitology, University of Glasgow, Bearsden, Scotland

Extract

The amount of [14C]methionine in the stomach, anterior and posterior intestine wall and lumen, blood and caecum of a rat, and in the anterior and posterior parts of the tapeworm Hymenolepis diminuta in the intestine, was measured at intervals from 10 min to 10 h after feeding a meal of 2 g glucose and 37.5 mg methionine by stomach tube.

Nearly all the meal left the stomach within 5 h; the amount entering the tapeworm depended on the position of the worm. That part lying in the anterior half of the intestine was subjected to a rapid influx reaching a maximum concentration of at least 8 mM within 1–3 h after the meal was administered. The level in the worm then dropped to about 20 % of the peak level, although the stomach was still emptying and the level of methionine in the intestine wall was still rising. This was a stable state, and equal to the concentration in the posterior part of the worm which was reached 2 h after the rat was fed.

The reason why the anterior part of the worm should show a big influx and efflux is discussed and related to changes in concentration of methionine in the lumen. The lack of such a flux into and out of the worm further down the intestine is related to the host's homeostatic control of amino acid balance in the intestine.

The results prove that dietary imbalance of amino acids affect the amino acid pool in a tapeworm for about 3 h, if it lies in the anterior of the gut. A dietary regime is suggested which should produce a prolonged effect and thereby retard growth of the worm.

The weights of the parts of the worms found in the anterior and posterior half of the small intestine revealed an unexpected phenomenon; the majority of the tapeworm, by weight, lies in the anterior of the intestine for about 4 h following a meal, but in the posterior of the intestine after the stomach has emptied.

It is a great pleasure to thank Miss Gillian Moore and Miss Patricia Grant for technical assistance, and Shell International Petroleum Company, London, for financial support.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1969

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Campbell, J. W. (1963). Amino acids and nucleotides of the cestode Hymenolepis diminuta. Comp. Biochem. Physiol. 8, 181–5.CrossRefGoogle Scholar
Chandler, A. C. (1939). The effects of number and age of worms on development of primary and secondary infections with Hymenolepis diminuta in rats, and an investigation into the true nature of ‘premunition’ in tapeworm infections. Am. J. Hyg. 29, 105–14.Google Scholar
Chandler, A. C. (1943). Studies on the nutrition of tapeworms. A. J. Hyg. 37, 121–30.Google Scholar
Crompton, D. W. T. & Whitfield, P. J. (1968). A hypothesis to account for the anterior migrations of adult Hymenolepis diminuta (Cestoda) and Moniliformis dubius (Acanthocephala) in the intestine of rats. Parasitology 58, 227–9.CrossRefGoogle ScholarPubMed
Dawson, R. (1964). General discussion. In The Role of the Gastrointestinal Tract in Protein Metabolism, p. 306. Ed. Munro, H. N.. Oxford: Blackwell.Google Scholar
Dawson, R., Holdsworth, E. S. & Porter, J. W. G. (1964). The digestion and absorption of protein in the rat. In The Role of the Gastrointestinal Tract in Protein Metabolism. Ed. Munro, H. N.. Oxford: Blackwell.Google Scholar
Geiger, E., Human, L. E. & Middleton, M. J. (1958). Nitrogen content of gastrointestinal tracts of rats during absorption period. Proc. Soc. exp. Biol. Med. 97, 232–4.Google Scholar
Goodchild, C. G. (1958). Transfaunation and repair of damage in the rat tapeworm, Hymenolepis diminuta. J. Parasit. 44, 345–51.CrossRefGoogle ScholarPubMed
Gupta, J. D., Dakroury, A. M. & Harper, A. E. (1958). Observations on protein digestion in vivo. J. Nutr. 64, 447–56.Google Scholar
Holmes, J. C. (1961). Effects of concurrent infections on Hymenolepis diminuta (Cestoda) and Moniliformis dubius (Acanthocephala). I. General effects and comparisons with crowding. J. Parasit. 47, 209–161.CrossRefGoogle ScholarPubMed
Holmes, J. C. (1962). Effects of concurrent infections on Hymenolepis diminuta (Cestoda) and Moniliformis dubius (Acanthocephala). II. Effects on growth. J. Parasit. 48, 8796.CrossRefGoogle ScholarPubMed
Hopkins, C. A. & Callow, L. L. (1965). Methionine flux between a tapeworm (Hymenolepis diminuta) and its environment. Parasitology 55, 653–66.CrossRefGoogle ScholarPubMed
Hopkins, C. A. & Young, R. A. L. (1967). The effect of dietary amino acids on the growth of Hymenolepis diminuta. Parasitology 57, 705–17.Google Scholar
Hunt, J. N. (1959). Gastric emptying and secretions in man. Physiol. Rev. 39, 491533.CrossRefGoogle ScholarPubMed
Karel, L. (1948). Gastric absorption. Physiol. Rev. 28, 433–50.CrossRefGoogle ScholarPubMed
Mettrick, D. F. & Munro, H. N. (1965). Studies on the protein metabolism of cestodes. I. Effect of host dietary constituents on the growth of Hymenolepis diminuta. Parasitology 55, 453–66.Google Scholar
Nasset, E. S. (1957). Role of the digestive tract in the utilization of protein and amino acids. J. Am. med. Ass. 164, 172–7.Google Scholar
Nasset, E. S. (1964). The nutritional significance of endogenous nitrogen secretion in nonruminants. In The Role of the Gastrointestinal Tract in Protein Metabolism. Ed. Munro, H. N.. Oxford: Blackwell.Google Scholar
Nasset, E. S. & Ju, J. S. (1961). Mixture of endogenous and exogenous protein in the alimentary tract. I. Nutr. 74 461–5.Google Scholar
Read, C. P., Rothman, A. H. & Simmons, J. E. (1963). Studies on membrane transport with special reference to parasite-host integration. Ann. N. Y. Acad. Sci. 113 154205.Google Scholar
Rogers, Q. R & Harper, A. E. (1964). Transfer rates along the gastrointestinal tract. In The Role of the Gastrointestinal Tract in Protein Metabolism. Ed. Munro, H. N., Oxford: Blackwell.Google Scholar
Thomas, J. E. (1957). Mechanics and regulation of gastric emptying. Physiol. Rev. 37 453–74.Google Scholar
Wilson, T. H. (1962). Intestinal Absorption. London: W. B. Saunders and Co.Google Scholar