Abstract
Reproducible results describing the effects of pH on the response of the labellar sugar receptor of the fleshfly, Boettcherisca peregrina, were obtained. The response to sucrose was independent over a wide range of pH (3.0 to 10.0 for sucrose stimulation), but was inhibited fairly sharply on both sides of this range. Similar results were obtained for monosaccharide stimulation. The receptor was excited on stimulation by water above pH 12.0. The effects of high pH, both inhibitory and excitatory, were affected by the presence of salts. In the presence of 0.5 molar NaCl, for example, the pH-inhibition curve was shifted toward lower pH's by about one pH unit. The effects of low pH, on the other hand, were not affected by salts. Following Dixon's theory, it was concluded that at least five ionizable groups (loosing positive charges above pH 10.5) were located at the receptor site.
Full Text
The Full Text of this article is available as a PDF (943.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- EVANS D. R., MELLON D., Jr Stimulation of a primary taste receptor by salts. J Gen Physiol. 1962 Mar;45:651–661. doi: 10.1085/jgp.45.4.651. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gillary H. L. Stimulation of the salt receptor of the blowfly. I. NaCl. J Gen Physiol. 1966 Nov;50(2):337–350. doi: 10.1085/jgp.50.2.337. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MORITA H. Initiation of spike potentials in contact chemosensory hairs of insects. III. D.C. stimulation and generator potential of labellar chemoreceptor of calliphora. J Cell Comp Physiol. 1959 Oct;54:189–204. doi: 10.1002/jcp.1030540209. [DOI] [PubMed] [Google Scholar]