Ester sulfate, excretion

D-glucuronic acid in the rabbit,1 but do not increase the ester sulfate excretion in this species on the other hand, the synthetic estrogens increase the ester sulfate excretion in the rat and, perhaps, in the cat and dog, but the levels vary greatly.110... 

It is assumed that phenols can conjugate directly with D-glucuronic acid or sulfuric acid. The scheme explains why phenols do not conjugate with mercapturic acid. Parke and Williams128 have recently shown that administration of phenylmercapturic acid or phenylcysteine to the rabbit is followed by the excretion of phenylcysteine, ester sulfates, and thio-phenol, and phenylcysteine also yields diphenyl disulfide. The thiol donor... 

The metabolism of epinephrine has received special attention lately. Older experiments had indicated that a large part of dexZro-epinephrine is excreted in a combined form after a large dose, and, since the ester sulfate fraction of the urine was elevated, it was assumed that this indicated sulfate conjugation of otherwise-unchanged epinephrine.234 Deichmann236 claimed that the only conjugate of Zero-epinephrine excreted by the rabbit is a sulfate, since he found that Zero-epinephrine increases the ratio of... 

L. Baldertorp and J. Martensson, Urinary Excretion of Inorganic Sulfate, Ester Sulfate, total Sulfur and Taurine in Cancer Patients, Acta Medica Scand 208 (1980) 293-295. 

Progesterone is metabolized very intensively in both the placental and fetal compartments (see Section III, B, 1, a and 2, o) in this last compartment part of the progesterone is transformed into pregnanediol-Sa-sulfate and part into 20a-dihydroprogesterone-20a-sulfate. These conjugates arc secreted to the placenta, where the placental sulfatases are not very active for these ester sulfates. Consequently, they cross the placenta without hydrolysis and are excreted in this form in the maternal urine. 

Pregnanetiiol, which is the principal metabolite of ITte-hydroxypro-gesterone, is excreted as glucuronide (80%) and as ester sulfate (20%) during pregnancy (Shen et ah, 1963). 

As a result of the prolongation of the deficiency of the 3/3-hydroxy-dehydrogenase, As — A isomerase system after birth, an important quantity of 3 -hydroxy-As steroids is excreted in the urine of newborns. As the 16a-hydroxylase is very active in the first days of life, very little if any dehydroepiandrosterone or dehydroepiandrosterone sulfate is excreted in newborn urine (Migeon et al., 1957b Vestergaard, 1965 Bertrand et al., 1966 Paulsen et al., 1966) on the other hand, the total excretion rate of urinary 16a-hydroxydehydroepiandrosterone is 300-600 )tig/24 hours (Bongiovanni, 1962 Mitchell and Shackleton, 1966 Mitchell, 1967). Cleary and Pion (1968) found these values to be between 0.7 and 3 mg/24 hours in the first 2 days of life. Alost of these steroids arc eliminated as ester sulfates. 

A4 isomerase deficiency in the first period of life, most of the C19 steroids have a Aj-SiQ,Ifia-dihydroxy structure and are excreted in urine principally as ester sulfates. 

Glucuronidation. Complexation of the steroid to glucuronic acid, most predominantiy via the C-3 hydroxyl, leads to a considerable portion of the excreted metabohtes of ah. glucocorticoids. In infants, sulfurylation (formation of a sulfate ester) is also predominant (16). 

Substrates for the sulfotransferases include such varied compounds as primary and secondary alcohols, hydroxysteroids, phenols, organic hydroxylamines, and amines. As is the case with formation of glutathione and glucuronide conjugates, the formation of a sulfate ester usually renders a substance more polar and more readily excreted. Several reviews on the multiple forms of sulfotransferases and their specificities and properties are available (133-135). 

Thiabendazole is administered orally and is rapidly absorbed from the intestinal tract, with peak plasma levels achieved in 1 to 2 hours. The drug is metabolized in the liver and excreted in urine within 24 to 48 hours as glucuronide and sulfate esters. Approximately 10% is found in feces. 

About 5-10% of steroids are excreted as free compounds. 3/i-I Iydroxy-5-ene steroids are almost exclusively excreted as sulfate esters, ring-A reduced steroids are excreted as glucuronides. 

Among the variety of sulfate esters formed by living cells are the sulfate esters of phenolic and steroid compounds excreted by animals, sulfate polysaccharides, and simple esters, such as choline sulfate. The key intermediate in the formation of all of these compounds lias been shown to be 3 -phosphoadenosine-5/-phosphosulfate (PAPS). This nucleotide also serves as an intermediate in sulfate reduction. 

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