The metabolism of dipotassium 2-hydroxy-5-nitrophenyl [35S]sulphate, a substrate for lysosomal arylsulphatases A and B

Abstract

The metabolic fate of dipotassium 2-hydroxy-5-nitrophenyl [(35)S]sulphate ([(35)S]NCS), a chromogenic substrate for lysosomal arylsulphatases A and B, has been studied in rats. Intraperitoneal injection of [(35)S]NCS into free-ranging animals is followed by excretion of the bulk of the radioactivity in the urine within 24hr., less than 13% being eliminated as inorganic [(35)S]sulphate. Most of the urinary radioactivity can be accounted for as [(35)S]NCS, but small amounts of a labelled metabolite are also present. Experiments in which [(35)S]NCS was injected intravenously into anaesthetized rats with bile-duct and bladder cannulae confirm that the ester is rapidly excreted in the urine. However, small amounts of radioactivity appear in bile, mainly in the form of the metabolite detected in urine. When [(35)S]NCS is perfused through the isolated rat liver, about 35% of the dose is hydrolysed within 3hr. Similar results are obtained if [(35)S]NCS is injected into anaesthetized rats in which kidney function has been eliminated by ligature of the renal pedicles. The labelled metabolite has been isolated from bile obtained by perfusing several rat livers with blood containing a total of 100mg. of [(35)S]NCS. It has been identified as 2-beta-glucuronosido-5-nitrophenyl [(35)S]sulphate. The implications of the various findings are discussed. The Appendix describes the preparation of [(35)S]NCS.

The development of arylsulphatase in the small intestine of the rat

“…One might have greater insight into the role of the neonatal increase in arylsulphatase if one knew the function of the enzyme; even its main substrate in vivo is as yet unidentified. Hydrolysis of [35S]-NCS in the rat does occur in vivo and in the perfused liver (Flynn, Dodgson, Powell & Rose, 1967). Other sulphate esters are also hydrolysed in vivo (Davis et al 1950;Dodgson & Tudball, 1960), but not under catalytic regulation of arylsulphatases of the type examined in the present study (Burstein, 1967;French & Warren, 1967).…”

Liberation of sulfate from sulfate esters by soils

“…Chemicals. Radioactively labeled sulfate esters were prepared from 35S-labeled sulfuric acid (98%) or chlorosulfonic acid (Radiochemical Centre, Amersham, Bucks., U.K.) by the following methods: choline [35S]sulfate, 13.6 ,tCi/mg (29); dipotassium 2hydroxy-5-nitrophenyl [35S]sulfate, 10.8 ,.Ci/mg (15); potassium dodecyl [35S]sulfate, 18.1 /Ci/mg (2); potassium p-nitrophenyl [U5S]sulfate, 13.1 ,zCi/mg (11); potassium glucose [6-35S]sulfate, 10 ,uCi/ mg (24); potassium phenyl [35S]sulfate, 15.8 ,tCi/ mg (19); potassium L-tyrosine O-L35S]sulfate, 3.7 ,mCi/ mg (6). Potassium tyrosylglycine 0-[V5S]sulfate (3.12 ,Ci/mg) was prepared by the method employed for L-tyrosine 0-sulfate but substituting equimolar quantities of tyrosylglycine for L-tyrosine.…”

Metabolic fates of diethylstilboestrol sulphates in the rat

“…The measurement of radioactivity in urine, bile and blood samples was as described by Flynn et al (1967) (Milsom et al, 1972) After radioautography, thin-layer plates were sprayed with phosphoric acid/ethanolic 0.2 % naphtharesorcinol (1:22, v/v), and heated at 105°C for 10min (Randerath, 1963 Aqueous solutions of metabolite A (1 ml, containing approx. 0.3mg) were injected intravenously into anaesthetized male rats.…”