Phenols, Urinary

In order to reach a conclusion when and how and, and to some extent, how much of a particular insecticide was administered, the form and quantity in which the insecticide exists in different tissues and in blood and urine may give valuable clues. Indeed, an intelligent deduction is also based on the knowledge of metabolic pathways and formation of other derivatives. Thus, as parathion is excreted in the urine ultimately as p-nitro-phenol, urinary p-nitrophenol levels may indicate the extent of exposure to parathion ). In cases of mild and moderate exposure, the excreted p-nitrophenol in urine was found to be of the order of 0.057 to 0.322 mg. percent. In severe and fatal cases of poisoning by parathion, the level of p-nitrophenol in urine was from 0.16 to 1.16 mg. percent. para-Nitrophenol thus is rapidly excreted in urine and no longer detected 48 hours after the exposure to the pesticide. 

Finally, the fact that anthocyanins can reach the brain represents a beginning of an explanation of the purported neuroprotection effects of anthocyanins. Anthocyanins may be eliminated via urinary and biliary excretion routes. " The extent of elimination of anthocyanins via urine is usually very low (< 0.2% intake) in rats and in humans, indicating either a more pronounced elimination via the bile route or extensive metabolism. As mentioned earlier, in the colon, non-absorbed or biliary excreted anthocyanins can be metabolized by the intestinal microflora into simpler break-down compounds such as phenolic acids that may be (re)absorbed and conjugated with glycine, glucuronic acid, or sulfate and also exhibit some biological... 

The urinary amino acids reflect both their high concentration in the blood, due to poor functioning of the liver, and failure of renal tubular reabsorption. The phenolic acids and tyrosine in the urine are evidence... 

Behavioral observations of male white-tailed deer indicate that urine could play a role in olfactory communication in this animal [131]. To extend the knowledge of the urinary volatiles of the white-tailed deer and to investigate the possibility that vaginal mucus could also carry semiochemical information, Jemiolo et al. [132] studied the qualitative and concentration changes in the profiles of the volatiles present in these excretions. Forty-four volatiles were found in the mucus and 63 in female urine. The volatiles common to both vaginal mucus and urine included alcohols, aldehydes, furans, ketones, alkanes, and alkenes. Aromatic hydrocarbons were found only in the mucus, whereas pyrans, amines, esters and phenols were found only in the urine. Both estrous mucus and estrous urine could be identified by the presence of specific compounds that were not present in mid-cycle samples. Numerous compounds exhibited dependency on ovarian hormones. 

Consideration of these data in terms of multi-compartmental analysis is found in Fig. 5. The renal compartment never achieved more than 6.3% of the administered dose and declined rapidly after 1 hr. As early as 10 min. the hepatic compartment contained about 18% of the administered compound where a peak value occurred at 2 hrs. and continued to contain large amounts of phenol red for up to 12 hrs. There is only a slight difference between the amount of phenol red handled by the urinary and biliary compartments in 48 hrs., 40% and 48% respectively. In each compartment most of the material is free drug. 

Effects of Interrupted Enterohepatic Circulation on Biliary and Urinary Handling of Phenol Red... 

The values in Table I compare biliary and urinary excretion of phenol red. The intact animal excretes 49% of the administered dose in 48 hrs. into gall bladder bile and of this 20% is excreted... 

Table I. Comparison of Urinary and Biliary Excretion of Phenol Red in Intact and in Fistulized Dogfish Shark3...

Since probenecid is used extensively as an inhibitor of the urinary and biliary excretion of carboxylic, phenolic and sulphonic acids in many other animals, it was of interest to determine if probenecid would inhibit the urinary and/or biliary transport of phenol red in the shark (Table IV). The plasma levels determined at 4 hrs. after administration of phenol red alone or in combination... 

Table V contains data for two model substances, p-aminohippurate (PAH) and phenol red. Consideration of the highest values in this table tells you where the major portions of the substances appear. For example, urine and bile show the largest concentrations of PAH and phenol red. Both compounds appear in significant concentrations in the kidney while the values in muscle, brain and cerebrospinal fluid (CSF) are invariably lower than the values seen in plasma. The values in parentheses (Table V) are percent of the administered dose in a given tissue or fluid compartment. They add to the previous information by revealing the overall importance of a particular compartment in the disposition of a substance. For example, while the hepatic concentrations of PAH and phenol red at 4 hrs. are only about 2-fold those of plasma, the large size of the shark liver relative to its body weight, typically about 10%, leads to the appearance of 30-40% of these substances in the liver. The relative handling of these compounds by the urinary and biliary system is obvious from considering the percentage figures. Thus in 24 hours phenol red is about equally distributed in the bile and urine (38 vs 31%) the urinary route is the dominant route of excretion of PAH, i.e., 56 vs 2%.

Steady-state appeared to be achieved within 3 hours after initiating exposure steady-state retention was 60-88%. Urinary recovery of phenol that had been retained in the lungs was 99 8% within 24 hours after initiating exposure. 

Total urinary phenol was determined at about 7 hours into an 8-hour shift in Bakelite workers exposed to airborne phenol at 0.16-32 ppm (Ohtsuji and Ikeda 1972). Daily urinary excretion of total phenol was 99% of the estimated amount inhaled indicating that phenol is readily absorbed. However, lung retention was not measured, and the contribution of percutaneous absorption to urinary phenol could not be evaluated in this study. 

Phenol absorbed through the lungs is excreted rapidly in urine in its free and conjugated forms. Within 24 hours after human subjects inhaled phenol at concentrations of 6-20 mg/m3 (1.5-5.1 ppm), 99 8% of the phenol retained in the lungs was excreted (Piotrowski 1971). The urinary excretion of phenol was studied in... 

Urinary excretion of total phenol (free and conjugates) is considered a biomarker of exposure for phenol. The biological exposure index (BEI) for phenol, for exposure to 5 ppm in air, is 250 mg/g creatinine when measured at the end of the shift (ACGIH 1991). 

Phenol absorbed from the gastrointestinal tract is excreted rapidly in urine as free phenol or conjugates (Capel et al. 1972 Deichmann 1944 Edwards et al. 1986 French et al. 1974 Kao et al. 1979 Kenyon et al. 1995 Liao and Oehme 1981). In 3 human subjects who received a single oral dose of 0.01 mg/kg [14C]-labeled phenol, the mean 24-hour urinary recovery of 14C was 90% (range 85-90%) of the administered dose (Capel et al. 1972). In this same study, urinary recovery of orally administered [14C]-labeled phenol was determined in 18 other mammalian species the mean 24-hour recoveries of 14C ranged from 95% in the rat to 31% in the squirrel monkey. 

Both urinary and fecal excretion of 14C was determined in rats administered an oral dose of 1.2 mg/kg of [14C]-labeled phenol (Edwards et al. 1986). Rats excreted 80.3 11.2% in the urine and 1.8 1.6%inthe feces in 24 hours. In rats exposed orally to radiolabeled phenol, elimination was 95% complete after 72 hours, with the primary elimination route being through the urine (Hughes and Hall 1995). Fecal elimination was slower and less overall. 

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