Glutathione S-transferases in earthworms (Lumbricidae)

Glutathione S-transferase activity (EC 2.5.1.18) was demonstrated in six species of earthworms of the family Lumbricidae: Eisenia foetida, Lumbricus terrestris, Lumbricus rebellus, Allolobophora longa, Allolobophora caliginosa and Allolobophora chlorotica. Considerable activity was obtained with 1-chlorl-2,4-dinitrobenzene and low activity with 3,4-dichloro-1-nitrobenzene, but no enzymic reaction was detectable with sulphobromophthalein 1,2-epoxy-3-(p-nitrophenoxy)propane of trans-4-phenylbut-3-en-2-one as substrates. Enzyme prepartations from L. rubellus and A. longa were the most active, whereas A. chlorotica gave the lowest activity. The ratio of the activities obtained with 1-chloro-2,4-dinitrobenzene and 3,4-cichloro-1-nitrobenzene was very different in the various species, but no phylogenetic pattern was evident. Isoelectric focusing gave rise to various activity peaks as measured with 1-chloro-2,4-dinitrobenzene as a substrate, and the activity profiles of the species examined appeared to follow a taxonomic pattern. The activity of Allolobophora had the highest peak in the alkaline region, whereas that of Lumbricus had the highest peak in the acid region. Eisenia showed a very complex activity profile, with the highest peak ne pH 7. As determined by an enzymic assay, all the species contained glutathione, on an average about 0.5 mumol/g wet wt. Conjugation with glutathione catalysed by glutathione S-transferases may consequently be an important detoxification mechanism in earthworms.

Acephaline gregarines of British earthworms–their possible host specificity

The host-specificity of monocystids was investigated experimentally by infesting infection-free Dendrobaena subrubicunda f. typica with sporocysts of Apolocystis megagranulata and A. lavernensis normally found in Dendrobaena subrubicunda and Allolobophora longa respectively. An attempt to infect worms raised free from infection with sporocysts of Monocystis agilis normally harboured by Lumbricus spp. was unsuccessful. Eighteen of the thirty identified monocystids were found to be monobiotic (species-specific), eleven were oligobiotic (genus-specific) and only one was polybiotic (family-specific).The writer wishes to express his sincere appreciation to Dr Anne Terry for her advice and useful suggestions, and to Mr D. Etherington, the head of department, for his encouragements throughout the research period.

On the Physiology and Pharmacology of the Earthworm Gut

1. The gut of Lumbricus terrestris and Allolobophora longa was studied. 2. The normal movements of the different parts of the gut, isolated and suspended in Ringer's fluid, are described. 3. Acetylcholine excites all parts of the gut. The "crop and gizzard" preparation is very sensitive to acetylcholine and shows a graded series of responses over a wide range of concentrations. It may therefore prove to be useful in the assay of acetylcholine. 4. The action of acetylcholine on the crop and gizzard is only slightly increased by eserine or prostigmine. The potentiation is especially noticeable in the presence of other drugs (adrenaline, histamine) which interfere with the acetylcholine action. 5. The action of acetylcholine on the crop and gizzard is abolished by atropine. 6. Adrenaline excites the buccal cavity, pharynx and oesophagus in all concentrations. On the crop, gizzard and intestine it has two actions, inhibition above and excitation below a certain threshold concentration, whose magnitude varies somewhat from worm to worm. 7. The action of adrenaline is slightly increased by ephedrine, and abolished by ergotoxine. 8. The actions of choline, histamine, potassium and calcium on the crop and gizzard are described. 9. The crop and gizzard receive two sets of nerves: (a) Exciting nerves, coming along the gut wall from the circumpharyngeal nerve ring; action abolished by atropine; probably cholinergic. (b) Inhibiting nerves, coming along the septa from the ventral nerve cord; action abolished by ergotoxine; probably adrenergic.