The relationship between the transport of glucose and cations across cell membranes in isolated tissues XI. The effect of vanadate on 45Ca-efflux and sugar transport in adipose tissue and skeletal muscle |
| |
Authors: | Torben Clausen Tove Lindahl Andersen Marianne Stürup-Johansen Olga Petkova |
| |
Institution: | 1. Institute of Physiology, University of Aarhus, 8000-Aarhus C Denmark;2. Department of Biochemistry, Agricultural University, Stara Zagora Bulgaria |
| |
Abstract: | (1) The effects of vanadate of hexose transport, 45Ca-exchange and (Na+, K+)-contents have been characterized in isolated adipose tissue and skeletal muscles of the rat. (2) In whole epididymal fat pads, vanadate (0.5–5.0 mM) markedly stimulated the uptake of 2-deoxyl14C]glucose as well as the efflux of . (3) Within the same concentration range, vanadate induced an early increase in 45Ca-washout from preloaded fat pads. The maximum increases in the fractional losses of and 45Ca were significantly correlated (, ). (4) In extensor digitorum longus and soleus muscles, vanadate (0.5–5.0 mM) stimulated the efflux of and this effect was preceded by a rise in the washout of 45Ca. The maximum increases in the fractional losses of and 45Ca were significantly correlated (, ). (5) In extensor digitorum longus and soleus muscles, vanadate increased K+-contents and decreased Na+ contents. (6) The stimulation of 45Ca-washout presumably reflects an increase in the cytoplasmic Ca2+ level, brought about by an inhibitory effect of vanadate on the Ca2+-sensitive ATPase of the sarcoplasmic or the endoplasmic reticulum. As demonstrated for most other insulin-like agents (Sørensen, S.S., Christensen, F. and Clausen, T. (1980) Biochim. Biophys. Acta 602, 433–445), the stimulating effect of vanadate on glucose transport appears to be associated with or mediated by a rise in the cytoplasmic Ca2+ level. |
| |
Keywords: | Sugar transport Vanadate (Rat) |
本文献已被 ScienceDirect 等数据库收录! |
|