Concanavalin A (Con A) has been shown to induce delays in oral regeneration in the ciliate Stentor coeruleus. Associated with the delayed oral regeneration is a shedding of the cell's extracellular pellicle with the loss of some pigment granules. It is shown that the delays in oral regeneration are
Pharmacological evidence for cell surface control of oral regeneration in Stentor coeruleus
โ Scribed by Michael S. Maloney
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- English
- Weight
- 634 KB
- Volume
- 103
- Category
- Article
- ISSN
- 0021-9541
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โฆ Synopsis
Abstract
This study suggests that membrane perturbations can affect oral morphogenesis in Stentor, possibly by a mechanism involving calcium ions. Exposure of regenerating Stentor to micromolar concentrations of the membrane active local anesthetics dibucaine, tetracaine, or procaine greatly delayed the progress of oral regeneration. In the case of tetracaine and dibucaine the greatest delays were observed in the early stages of regeneration prior to stage 4, when the majority of essential synthetic activity is occurring. The effects of dibucaine were generally readily reversible upon removal of the cells from the drug, with some residual effects occurring at higher dibucaine concentrations. Regenerating cells in the presence of dibucaine and excess extracellular calcium were not delayed, suggesting that the effects of dibucaine were reversible by calcium ions. The effects of tetracaine were not reversible by calcium ions, however. Exposure of regenerating cells to medium either lacking in, or containing an excess of, extracellular calcium had no effect on the time required to complete oral regeneration. The plant lectin, phytohemagglutinin, can also delay oral regeneration. The possible implications of these findings on the control of oral regeneration are discussed.
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