QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by MURDOCK, L. L. Articles by KOIDL, B. Search for Related Content PubMed Articles by MURDOCK, L. L. Articles by KOIDL, B.

Journal of Experimental Biology 56,781-794 (1972)
Published by Company of Biologists 1972

Limited Permeability and Metabolism of L-Glutamate in the Locust Gut Wall

L. L. MURDOCK ¹ and B. KOIDL ¹

¹ Fachbereich Biologie, Universität Konstanz, 775 Konstanz, West Germany

1. A method is described which enables the passage of nutrients through the gut wall of locusts to be studied quantitatively in vivo. The method consists of infusing the radio-labelled precursor into the gut lumen while the haemocoel is perfused with saline. The perfusate is collected and analysed.

2. Compared to L-alanine and glycine, intact L-glutamate crosses the locust gut wall slowly, if at all.

3. Metabolism of L-glutamate in the gut wall is extensive, that of alanine markedly less, while there is little metabolism of glycine.

4. It is suggested that limited permeability and extensive metabolism in the gut wall combined to severely restrict the entry of intact dietary L-glutamate into the blood.

5. The gut wall may be an important site of regulation of blood L-glutamate, preventing or hindering influx of this abundant dietary amino acid. The system could be a contributing factor in protecting neuromuscular synapses from non-adaptive excitation by helping to prevent the concentration of blood L-glutamate from rising.