Abstract
1. The rates of influx and efflux of [32P]orthophosphate (Pi) have bben measured in single muscle fibres of the spider crab, Maia squinado. 2. Rates of influx of 32Pi from salines containing 0 . 11 to 0 . 37 mM-Pi ranged from 0 . 11 to 0 . 41 p-mole cm-2 sec-1. 3. After injection of [32P]orthophosphate there was an early rapid phase of 32P efflux which was maximal after about 5-10 min, then a gradual decline until a low steady-state efflux rate was established after about 100 min. The rate of decline of 32P efflux was similar to the rate of equilibration of injected 32Pi with arginine phosphate and ATP. 4. The steady-state rate of 32P efflux was typically about 0 . 70 p-mole cm-2 sec-1 when the sarcoplasmic Pi concentraion was 5 m-mole kg-1. Exposure of mucle fibres to conditions which caused contraction and increased the sarcoplasmic concentration of Pi also increased the rate of 32P efflux, which appeared to be linearly related to sarcoplasmic Pi concentration. 5. The results are compared with previous measurements of phosphate fluxes in nerve.
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Selected References
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- Anner B., Ferrero J., Jirounek P., Jones G. J., Salamin A., Straub R. W. Sodium-dependent influx of orthophosphate in mammalian non-myelinated nerve. J Physiol. 1976 Sep;260(3):667–686. doi: 10.1113/jphysiol.1976.sp011538. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Anner B., Ferrero J., Jirounek P., Straub R. W. Uptake of orthophosphate by rabbit vagus nerve fibres. J Physiol. 1975 Jun;247(3):759–771. doi: 10.1113/jphysiol.1975.sp010956. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ashley C. C., Caldwell P. C., Lowe A. G. The efflux of calcium from single crab and barnacle muscle fibres. J Physiol. 1972 Jun;223(3):735–755. doi: 10.1113/jphysiol.1972.sp009872. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berenblum I., Chain E. An improved method for the colorimetric determination of phosphate. Biochem J. 1938 Feb;32(2):295–298. doi: 10.1042/bj0320295. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CALDWELL P. C., HODGKIN A. L., KEYNES R. D., SHAW T. I. THE RATE OF FORMATION AND TURNOVER OF PHOSPHORUS COMPOUNDS IN SQUID GIANT AXONS. J Physiol. 1964 May;171:119–131. doi: 10.1113/jphysiol.1964.sp007366. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CALDWELL P. C. Studies on the internal pH of large muscle and nerve fibres. J Physiol. 1958 Jun 18;142(1):22–62. doi: 10.1113/jphysiol.1958.sp005998. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CALDWELL P. C. The phosphorus metabolism of squid axons and its relationship to the active transport of sodium. J Physiol. 1960 Jul;152:545–560. doi: 10.1113/jphysiol.1960.sp006508. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CALDWELL P. C. The separation of the phosphate esters of muscle by paper chromatography. Biochem J. 1953 Oct;55(3):458–467. doi: 10.1042/bj0550458. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CALDWELL P. C., WALSTER G. STUDIES ON THE MICRO-INJECTION OF VARIOUS SUBSTANCES INTO CRAB MUSCLE FIBRES. J Physiol. 1963 Nov;169:353–372. doi: 10.1113/jphysiol.1963.sp007261. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caldwell P. C., Lea T. J. Glycine fluxes in squid giant axons. J Physiol. 1978 May;278:1–25. doi: 10.1113/jphysiol.1978.sp012289. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caldwell P. C., Lowe A. G. The influx of orthophosphate into squid giant axons. J Physiol. 1970 Apr;207(2):271–280. doi: 10.1113/jphysiol.1970.sp009060. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caldwell P. C., Walster G. E. The turnover of phosphorus compounds in crab muscle fibres. J Physiol. 1975 Jun;248(1):1–13. doi: 10.1113/jphysiol.1975.sp010959. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FATT P., KATZ B. The electrical properties of crustacean muscle fibres. J Physiol. 1953 Apr 28;120(1-2):171–204. doi: 10.1113/jphysiol.1953.sp004884. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HODGKIN A. L., KEYNES R. D. Experiments on the injection of substances into squid giant axons by means of a microsyringe. J Physiol. 1956 Mar 28;131(3):592–616. doi: 10.1113/jphysiol.1956.sp005485. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ritchie J. M., Straub R. W. Increase in efflux of inorganic phosphate during electrical activity in small non-myelinated nerve fibres. J Physiol. 1978 Jan;274:539–548. doi: 10.1113/jphysiol.1978.sp012165. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Solandt D. Y. The effect of potassium on the excitability and resting metabolism of frog's muscle. J Physiol. 1936 Feb 8;86(2):162–170. doi: 10.1113/jphysiol.1936.sp003351. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TASAKI I., TEORELL T., SPYROPOULOS C. S. Movement of radioactive tracers across squid axon membrane. Am J Physiol. 1961 Jan;200:11–22. doi: 10.1152/ajplegacy.1961.200.1.11. [DOI] [PubMed] [Google Scholar]
