Muscle tissue, phosphorus compounds

Phosphorus-32, for example, produced by irradiating sulphur or natural phosphorus ( P) with high-energy particles, has a half-life of 14.8 days and can be rapidly taken up (in the form of phosphate) by body tissues such as muscles, the liver, bones, and teeth. De Hevesy found that different phosphorus compounds would be incorporated in a tissue-specific manner certain compounds were concentrated in the liver, for example. One can use stable isotopes as biological tracers too, since they are detectable atom by atom using mass spectrometry. De Hevesy observed that it takes deuterium twenty-six minutes to pass from ingested heavy water into urine. 

Phosphorus NMR is also used for vascularly perfused preparations, such as heart, skeletal muscle, bladder, or uterus. In these cases, the contributions to the spectra by the perfusate may be important. Phe-nylphosphonate or similar derivatives are often used for such experiments. PPA has a direct C-P bond, unlike phosphates that have O-P bonds. As a result, PPA resonates downfield (to the left) of the naturally occurring phosphorus compounds. In mechanical and NMR experiments, the effects of PPA on the isolated, perfused bladder were measured (Fisher and Dillon, 1987a). PPA in concentrations up to 20 mM did not produce a significant reduction in force generation. Its NMR peak position was shown to be pH sensitive with a pK of 7.09, making it ideal for measurements of extracellular pH. It did not produce any alteration in the natural phosphorus spectrum, and it was able to be washed into and out of the perfused tissue without measurable residue, indicating that it did not cross cell membranes. In addition to being a pH indicator, it is therefore also useful as a marker for extracellular space. 

For example, tin and lead alkylates have been determined in soil, water, or muscle tissue with GC/MS after exhaustive alkylation or with thermospray [239], API [240], and ICP-LC/MS [244] methods. The ESI spectra of some tin compounds is given in Figure 36. The APIMS techniques have proven to be very successful, even with metals bound to proteins and enzymes [241] and. interfaced to microseparation techniques, even elements such as iodine [242] or phosphorus [243] can be determined quantitatively. 

A. Bate of Renewal of Labile Phosphorus Compounds of Muscle Tissue 113... 

A. RATE OF RENEWAL OF LABILE PHOSPHORUS COMPOUNDS OF MUSCLE TISSUE... 

In this chapter we discuss several clinical applications of P NMR. The main emphasis is placed on advances in skeletal muscle (since the review of Glonek et al., 1981), but advances in heart, kidney, brain, eye, and mammalian fluids are also covered. The resonances we deal with are from the phosphorus compounds soluble in the cytoplasm. At the time of this writing, the phospholipids in the membranes of intact tissues are not amenable for P-NMR analysis under the high-resolution conditions cus-... 

Organic.—Glycerophosphates and hexosephosphates phos-phatides phosphoproteins, and unidentified compounds. In plants, phosphorus occurs in phosphoproteins and in phytin— the Ca Mg salt of inositol-phosphoric acid. Various forms of muscle and blood phosphates are recognised analytically in animal tissues. 

---