Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-12-01T01:13:26.887Z Has data issue: false hasContentIssue false

The electrophysiology of the somatic muscle cells of Ascaris suum and Ascaridia galli

Published online by Cambridge University Press:  06 April 2009

K. T. Wann
Affiliation:
The Wellcome Research Laboratories, Langley Court, Beckenham, Kent BR3 3BS

Extract

The electrophysiological properties of the bag region of the somatic muscle cells of Ascaris suum and Ascaridia galli were studied using intracellular techniques. For Ascaris muscle cells, the mean resting membrane potentials at 20 and 37°C were −29·9 and −33·8 mV respectively, and the average input conductance was 2·12 μS. For the muscle cells of A. galli similar values were obtained. For example, the mean input conductance of these cells was 2·84 μS at 20°C. Healthy Ascaris muscle cells at near physiological temperatures show both spontaneous depolarizing and hyperpolarizing activity and, in cells close to the nerve cords, rhythmic large amplitude (approximately 30 mV) action potentials are observed. Such action potentials, which are very sensitive to temperature variations, originate in the muscle cells. In contrast the muscle cells of Ascaridia are quiescent. The rhythmic action potentials of Ascaris are resistant to tetrodotoxin (TTX) (≤ 10−6 M), verapamil (10−4 M) and cinnarizine (10−4 M), but are blocked irreversibly by 22, 23 dihydroavermectin B1a (10−7 to 5 × 10−6 M). GABA, and the GABAA receptor agonists, muscimol and isoguvacine, hyperpolarize and increase the input conductance of both Ascaris and Ascaridia muscle cells. The antagonists+bicuculline and picrotoxin were not effective in modulating the spontaneous hyper polarizations of Ascaris muscle cells, and picrotoxin (10−4 M) was not effective in altering the response to GABA (5 × 10−6 M). The significance of the results is discussed briefly.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1987

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

Aceves, J., Erlij, D. & Martinez-Maranon, R. (1970). The mechanism of the paralysing action of tetramisole on Ascaris somatic muscle. British Journal of Pharmacology 38, 602–7.CrossRefGoogle ScholarPubMed
Byerly, L. & Masuda, M. O. (1979). Voltage-clamp analysis of the potassium current that produces negative-going action potential in Ascaris muscle. Journal of Physiology 288, 263–84.CrossRefGoogle ScholarPubMed
Brading, A. F. & Caldwell, P. C. (1971). The resting membrane potential of the somatic muscle cells of Ascaris lumbricoides. Journal of Physiology 217, 605–24.CrossRefGoogle ScholarPubMed
Campbell, W. C. (1985). Ivermectin: an update. Parasitology Today 1, 1016.CrossRefGoogle ScholarPubMed
De Bell, J. T., Dell Castillo, J. & Sanchez, V. (1963). Electrophysiology of the somatic muscle cells of Ascaris lumbricoides. Journal of Cellular and Comparative Physiology 62, 159–77.CrossRefGoogle Scholar
Del Castillo, J. (1969). Pharmacology of Nematoda. In Chemical Zoology, vol. 3 (ed. Florkin, M. and Scheer, B. T.), pp. 521554. New York and London: Academic Press.CrossRefGoogle Scholar
Del Castillo, J., De Mello, W. C. & Morales, T. (1963). The physiological role of acetylcholine in the neuromuscular system of Ascaris lumbricoides. Archives Internationales de Physiologie et de Biochimie 71, 741–57.CrossRefGoogle Scholar
Del Castillo, J., De Mello, W. C. & Morales, T. (1964). Inhibitory action of γ-aminobutyric acid (GABA) on Ascaris muscle. Experientia 20, 141–3.CrossRefGoogle ScholarPubMed
Del Castillo, J., De Mello, W. C. & Morales, T. (1967). The initiation of action potentials in the somatic musculature of Ascaris lumbricoides. Journal of Experimental Biology 46, 236–79.Google ScholarPubMed
Duce, I. R. & Scott, R. H. (1985). Actions of dihydroavermectin B1a on insect muscle. British Journal of Pharmacology 85, 395401.CrossRefGoogle ScholarPubMed
Eyre, P. (1970). Some pharmacodynamic effects of the nematocides: methyridine, tetramisole and pyrantel. Journal of Pharmacy and Pharmacology 22, 2636.CrossRefGoogle ScholarPubMed
Fritz, L. C., Wang, C. C. & Gorio, A. (1979). Avermectin B1a irreversibly blocks postsynaptic potentials at the lobster neuromuscular junction by reducing muscle membrane resistance. Proceedings of the National Academy of Sciences, USA 76, 2062–6.CrossRefGoogle ScholarPubMed
Janis, R. A. & Triggle, D. J. (1983). New developments in Ca2+ channel antagonists. Journal of Medicinal Chemistry 26, 775–85.CrossRefGoogle ScholarPubMed
Jarman, M. (1959). Electrical activity in the muscle cells of Ascaris lumbricoides. Nature, London 184, 1244.CrossRefGoogle Scholar
Johnson, C. D. & Stretton, A. O. W. (1980). Neural control of locomotion in Ascaris: anatomy, electrophysiology and biochemistry. In Nematodes as Biological Models, (ed. Zuckerman, B. M.), pp. 159195. New York: Academic Press.Google Scholar
Kass, I. S., Wang, C. C., Walrond, J. P. & Stretton, A. O. W. (1980). Avermectin B1a, a paralyzing anthelmintic that affects interneurones and inhibitory motoneurones in Ascaris. Proceedings of the National Academy of Sciences, USA 77, 6211–15.CrossRefGoogle ScholarPubMed
Marder, E. & Paupardin-Tritsch, D. (1978). The pharmacological properties of some crustacean neuronal acetylcholine, γ-aminobutyric acid, and L-glutamate responses. Journal of Physiology 280, 213–36.CrossRefGoogle ScholarPubMed
Martin, R. J. (1980). The effect of γ-aminobutyric acid on the input conductance and membrane potential of Ascaris muscle. British Journal of Pharmacology 71, 99106.CrossRefGoogle ScholarPubMed
Martin, R. J. (1982). Electrophysiological effects of piperazine and diethylcarbamazine on Ascaris suum somatic muscle. British Journal of Pharmacology 77, 255–65.CrossRefGoogle ScholarPubMed
Natoff, L. L. (1969). The pharmacology of the cholinoceptor in muscle preparations of Ascaris lumbricoides var suum. British Journal of Pharmacology 37, 251–7.CrossRefGoogle ScholarPubMed
Rosenbluth, J. (1965 a). Ultrastructural organization of obliquely striated muscle fibres in Ascaris lumbricoides. Journal of Cell Biology 25, 495515.CrossRefGoogle ScholarPubMed
Rosenbluth, J. (1965 b). Ultrastructure of somatic muscle cells in Ascaris lumbricoides. Journal of Cell Biology 26, 579–91.CrossRefGoogle ScholarPubMed
Simmonds, M. A. (1983). Multiple GABA receptors and associated regulatory sites. Trends in Neurosciences 6, 279–81.CrossRefGoogle Scholar
Stretton, A. O. W., Fishpool, R. M., Southgate, E., Donmoyer, J. E., Walrond, J. P., Moses, J. E. & Kass, I. S. (1978). Structure and physiological activity of the motoneurones of the nematode Ascaris. Proceedings of the National Academy of Sciences, USA 75, 3493–7.CrossRefGoogle ScholarPubMed
van Den Bossche, H. (1980). Peculiar targets in anthelmintic chemotherapy. Biochemical Pharmacology 29, 1981–90.CrossRefGoogle ScholarPubMed
Van Neuten, J. M. (1972). Pharmacological aspects of tetramisole. In Comparative Biochemistry of Parasites, (ed. H., Van den Bossche), pp. 101115. New York and London: Academic Press.CrossRefGoogle Scholar
Wang, G. C. & Pong, S-S. (1982). Actions of avermectin B1a on GABA nerves. In Membranes and Genetic Disease, pp. 373395. New York: Alan R. Liss Inc.Google Scholar
Wann, K. T. (1975). Intracellular studies of the electrical characteristics of the frog skeletal muscle membrane. Ph.D. thesis, Aberdeen University.Google Scholar
Weisblat, D. A., Byerly, L. & Russell, R. L. (1976). Ionic mechanisms of electrical activity in somatic muscle of the nematode Ascaris lumbricoides. Journal of Comparative Physiology 111, 93113.CrossRefGoogle Scholar
Weisblat, D. A. & Russell, R. L. (1976). Propagation of electrical activity in the nerve cord and muscle syncytium of the nematode Ascaris lumbricoides. Journal of Comparative Physiology 107, 293307.CrossRefGoogle Scholar