Characterization of monovalent ion transport systems in an insect cell line (Manduca sexta embryonic cell line che)
✍ Scribed by Leigh H. English; Lewis C. Cantley
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- English
- Weight
- 774 KB
- Volume
- 121
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
The monovalent ion transport systems of an immortalized insect cell line (CHE) have been investigated. These cells are unusual in that unlike most vertebrate cells, their normal extracellular environment consists of high potassium and low sodium concentrations. CHE cells maintained high intracellular [K+] through both a furosemide-inhibitable and a vanadate-inhibitable transport system. lntracellular exchangeable "a+] was slightly lower than the extracellular "a'] and was maintained at this level through a vanadatesensitive transport system. Na+ uptake was also inhibited by furosemide: however, the stoichiometry of furosemide-sensitive Na+ uptake when compared with furosemide-sensitive K + uptake indicated that these cations are not cotransported. 4,4'-Diisothiocyano-2,2'-disulfonic acid stilbene (DIDS) inhibited Na+, K+, and CI-uptake. Vanadate and furosemide decreased cytoplasmimic pH, while cytoplasmic pH increased in the presence of DIDS. A model is presented explaining how Na+, K + , CI-, H + and HC03-fluxes are regulated in these cells.