Cyclic AMP and calcium exchange in a cellular slime mold

✍ Scribed by Yea-Yuan Chi; David Francis

• Book ID: 102309147
• Publisher: John Wiley and Sons
• Year: 1971
• Tongue: English
• Weight: 364 KB
• Volume: 77
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040770206

✦ Synopsis

Abstract

Cyclic AMP is known to be an effective chemotactic agent for amebae of the cellular slime mold D. discoideum. A large amount of information from experiments on metazoa suggested that one cellular effect of cyclic AMP might be to alter the permeability of the cell membrane to Calcium or Sodium ions.

On the basis of this information experiments were designed to test the effect of cyclic AMP on outflow of labeled Calcium or Sodium ions from amebae of D. discoideum. It was found that addition of cyclic AMP at 10^−4^M resulted in a large increase of Ca^45^ outflow from cells at the pre‐aggregative or aggregative stage of development. No effect was found on Na^22^ outflow.

It is suggested that this effect on Calcium permeability of the membrane is related to the chemotactic influence of ATP by some action on the contractile mechanism for ameboid movement. The phenomenon may be distinct from the enzyme inductive activity of cyclic AMP known for bacteria, and perhaps occurring in the cellular slime molds as well.