Diarrhoea – as intestinal contents are hurried through the G.I.tract.

2. In acute infections.

3. In nephritis – because failure of the kidneys to function adequately.

4. In parathyroid hypofunction – hypoparathyroidism.

5. Pregnancy – due to utilization of maternal PO4 in the formation of foetal bones.

6. During insulin administration as there is increased requirement of PO4 for the formation of hexose-phosphate.

7. Certain inherited disorders like Galactosaemia, hereditary fructose intolerance.

III. Sulfur Compounds in Urine

Forms of sulfur compounds

Sulfur is excreted in urine in three forms:

1. Inorganic SO4 – 80 to 85%

2. Organic esters or “ethereal sulfates” – 5%

3. Neutral sulfur – (organic sulfate) – 15 to 20%.

Source: Most of urinary sulfur arises from metabolism of proteins, specially from sulfur-containing aminoacids cysteine, cystine and Methionine.

Note:Methionine indirectly contributes through cysteine. A small amount obtained from S-containing vitamins like thiamine, Biotin, Lipoic acid. Food proteins contain on an average 1% of sulfur. Excretion of S in urine varies with:

(i) protein intake in diet and

(ii) rate of tissue protein break down.

Normal value and clinical significance: total urinary sulfur varies from 0.8 to 1.4gm per 24hrs (average =1.0gm). urinary N:S ratio = 13 to 16 on a high meat diet and during fasting.

1. Inorganic SO4

Makes greater proportion – 0.7 to 1.0gm per day, and constitutes 80 to 85% of total S excreted.

Decrease – The SO4 sulfur excretion may be diminished in conditions of renal functional impairment.

Increase: it is increased

(i) on high protein diets, and

(ii) in excessive tissue Proteins breakdown

Ethereal sulfur

Range from 0.06 to 0.12 gm/day. It consists ofNa and K salts of sulfuric acid esters of phenols such as indoxyl, skatoxyl, phenol and cresol. These ethereal SO4 represent detoxication compounds of phenols and are formed in liver. Some of the phenolic substances originate through:

(i) Bacterial action in the gut,

(ii) Some appears to be formed in tissue metabolism.

Indoxyl and skatoxyl are formed practically entirely by putrefactive decomposition of tryptophan in the gut and phenol and cresol from tyrosine. Both substances are esterified with H2SO4 in liver and excreted in urine as the Na and K salts. K-salt of indoxyl sulphuric acid is called as Indican and is excreted in urine.

<== попередня сторінка	\|	наступна сторінка ==>
Clinical significance	\|	Clinical importance: Excretion of Indican in urine is taken as a rough index of intestinal putrefaction.

Не знайшли потрібну інформацію? Скористайтесь пошуком google:

Генерація сторінки за: 0.003 сек.