Cholinoreceptors of the dentis retractor muscle of the sea urchin strongylocentrotus intermedius

Kobzar, Gennadi; Shelkovnikov, S. A.

doi:10.1016/0742-8413(85)90073-8

Cited by 4 publications

(1 citation statement)

References 15 publications

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“…Other studies on the dose^response relationship of acetylcholine in echinoderms have been done using muscles. Studies on the radial muscle of the sea urchin Asthenosoma ijimai (Tsuchiya & Amemiya 1977), on the lantern retractor muscle of the sea urchin Strongylocentrotus intermedius (Shelkovnikov et al 1977;Kobzar & Shelkovnikov 1985) and on the tube foot muscle of the star¢sh Asterias amurensis (Protas & Muske 1980) all had similar outcomes, i.e. a threshold concentration for acetylcholine of around 10 ¡7 M. The maximal tension was reached at 10 ¡4^1 0 ¡3 M, similar to the maximal values for softening at 10 ¡4 M in our study and at 10 ¡3 M of sea cucumber CCT (Motokawa 1981).…”

Section: (Ii) Acetylcholine Dose^response Curve In Comparisonmentioning

confidence: 99%

Cirri of the stalked crinoidMetacrinus rotundus: neural elements and the effect of cholinergic agonists on mechanical properties

Birenheide

Yokoyama

Motokawa

2000

Proc. R. Soc. Lond. B

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Sea lilies are enigmatic animals due to their scarcity and their biology is comparatively neglected. Cirri, arranged in whorls of five along the sea lily stalk, anchor and support the animal. They consist of ossicles interconnected by collagenous ligaments and by a central canal. Cirri have a well-developed nervous system but lack muscular cells. A light and electron microscopic study was performed to clarify the morphology of the nervous system of the cirri. Two cellular networks were found, one of neuron-like cells and one of cells filled with bullet-shaped organelles. Both networks ramify throughout the cirral ossicles up to the interossicle ligaments. Mechanical tests were performed to analyse the influence of cholinergic agonists on the mechanical properties of these ligaments. In the tests, the cirral ligaments softened after the application of acetylcholine, muscarinic agonists and nicotinic agonists. The reaction time to muscarinic agonists was much slower than to acetylcholine and nicotinic agonists. At low concentrations, muscarinic agonists caused active development of force. No reaction to stimuli was observed in anaesthetized cirri. The data clearly establish the existence of catch connective tissue which can change its mechanical properties under nervous control mediated via nerves with cholinergic receptors. The possible sources of the observed force production are discussed and it is concluded that active contraction of collagenous ligaments causes movement of cirri.

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Section: (Ii) Acetylcholine Dose^response Curve In Comparisonmentioning

confidence: 99%

Cirri of the stalked crinoidMetacrinus rotundus: neural elements and the effect of cholinergic agonists on mechanical properties

Birenheide

Yokoyama

Motokawa

2000

Proc. R. Soc. Lond. B

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Acetyl cholinesterase activity and muscle contraction in the sea urchin Lytechinus variegatus (Lamarck) following chronic phosphate exposure

Böettger

McClintock

2012

Environmental Toxicology

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The common shallow-water sea urchin Lytechinus variegatus is capable of surviving inorganic phosphate exposures as high as 3.2 mg L(-1) and organic phosphate exposures of 1000 mg L(-1) . Nonetheless, chronic exposure to low, medium, and high-sublethal concentrations of organic phosphate inhibits the muscle enzyme acetyl cholinesterase (AChE), responsible for the break down of the neurotransmitter acetylcholine, as well as inhibiting contractions in the muscles associated with the Aristotle's lantern. AChE activity, measured in both a static enzyme assay and by vesicular staining, displayed concentration-dependent declines of activity in individuals maintained in organic phosphate for 4 weeks. The activity of AChE was not adversely affected by exposure to inorganic phosphate or seawater controls over the same time period. Maximum force of muscle contraction and rates of muscle contraction and relaxation also decreased with chronic exposure to increasing concentrations of organic phosphate. Chronic exposure to inorganic phosphates elicited no response except at the highest concentration, where the maximum force of muscular contraction increased compared to controls. These findings indicate that shallow-water populations of Lytechinus variegatus subjected to organic phosphate pollutants may display impaired muscular activity that is potentially related to the inhibition of the muscle relaxant enzyme AChE, and subsequently muscular overstimulation, and fatigue.

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Mechanical properties of sea-urchin lantern muscles: a comparative investigation of intact muscle groups in Paracentrotus lividus (Lam.) and Stylocidaris affinis (Phil.) (Echinodermata, Echinoidea)

Wilkie¹,

Carnevali

Andrietti

1998

Journal of Comparative Physiology B: Biochemical, Systemic, and

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Cholinoreceptors of the dentis retractor muscle of the sea urchin strongylocentrotus intermedius

Cited by 4 publications

References 15 publications

Cirri of the stalked crinoidMetacrinus rotundus: neural elements and the effect of cholinergic agonists on mechanical properties

Cirri of the stalked crinoidMetacrinus rotundus: neural elements and the effect of cholinergic agonists on mechanical properties

Acetyl cholinesterase activity and muscle contraction in the sea urchin Lytechinus variegatus (Lamarck) following chronic phosphate exposure

Mechanical properties of sea-urchin lantern muscles: a comparative investigation of intact muscle groups in Paracentrotus lividus (Lam.) and Stylocidaris affinis (Phil.) (Echinodermata, Echinoidea)

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