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Biomedical subjects

A Karakaya

Publications and source records attributed to A Karakaya.

26 records · Page 2Linked to original sources
PubMed1991

Analysis of the serum paraoxonase/arylesterase polymorphism in a Turkish population.

Human serum paraoxonase is a polymorphic enzyme that is capable of catalyzing the hydrolysis of paraoxon and other organophosphates, some carbamates and certain aromatic carboxylic acid esters. This enzyme is specified by two allelic genes at one autosomal locus (isozymes 'A' and 'B'). The purpose of this study was to examine the paraoxonase activity of 105 Turkish subjects. Paraoxonase activities ranged from 39.6 to 278.2 nmol p-nitrophenol formed per ml of serum per min. Paraoxonase phenotypes could be clearly identified by salt and paraoxonase:arylesterase activity ratio characteristics. The gene frequencies were 0.632 for the low activity allele (A) and 0.368 for the high activity allele (B).

Adult↗
PubMed1988

Cadmium sensitivity differences between liver microsomal drug metabolizing enzyme systems of guinea-pig and rat.

1. Male guinea-pigs (400-500 g) and rats (225-275 g) were given a single dose of cadmium chloride (CdCl2) (2 mg Cd2+/kg i.p.) and 72 hr later the liver microsomal drug metabolizing enzyme activities and Cd levels of tissues and microsomes were determined. 2. No significant differences were noted between Cd treated and control animal tissue weights of microsomal protein contents in either guinea-pigs or rats. 3. Cd treatment exhibited significant inhibition of the activities of aniline 4-hydroxylase and ethylmorphine N-demethylase and on the levels of cytochrome P-450 and cytochrome b5 of liver of both species but the degree of inhibition were not the same in the species; they were 23, 34, 16 and 10% in guinea-pigs and 58, 57, 25 and 13% in rats, respectively. 4. No activity changes were observed in liver NADPH-cytochrome c reductase of the species by Cd treatment. 5. The duration of hexobarbital sleeping time was significantly prolonged in both species. However, the prolongation was 1.6 fold in guinea-pigs but 3.4 fold in rats. 6. No significant differences were found between either tissue or microsomal Cd levels of guinea-pigs and rats.

Aniline Hydroxylase↗
PubMed1988

Effect of cadmium on pulmonary and renal microsomal drug metabolizing enzymes of the guinea-pig.

1. The effect of acute cadmium (Cd) treatment on pulmonary and renal microsomal aniline 4-hydroxylase and ethylmorphine N-demethylase enzyme activities of adult male guinea-pigs were assessed 72 hr following a single dose of Cd ion (2 mg Cd2+/kg i.p.). Tissue and microsomal Cd levels were also determined. 2. There were no significant differences between either lung or kidney tissue weights, microsomal protein contents or enzyme activities of Cd treated and control animals. 3. The tissues and microsomes of Cd-treated animals were found to have significantly higher levels of Cd than those of control animals. In Cd treated animals, tissue and microsomal Cd levels of kidney were found to be higher than that of lung. 4. In vitro addition of cadmium chloride (CdCl2) to incubation mixtures produced concentration related inhibitions of microsomal drug metabolizing enzymes in each tissue. However, in vitro effect of CdCl2 was found to be stronger on drug metabolizing enzymes of kidney than those of lung. In addition, while the strength of Cd effect was more pronounced on the activity of ethylmorphine N-demethylase than that of aniline 4-hydroxylase in the lung, the opposite was observed in the kidney.

Animals↗
PubMed1987

Influence of cigarette smoking on thyroid hormone levels.

1 Serum triiodothyronine (T3), thyroxine (T4) and thyrotropin (TSH) concentrations and urinary thiocyanate levels were examined in healthy smokers and non-smokers as an indicator of smoking behaviour. Smokers were subdivided into moderate and heavy. 2 Significant differences in urinary thiocyanate levels were apparent between all three groups. For heavy smokers, serum T3 concentrations were significantly above the values found in non-smokers. Increased serum T3 levels were not accompanied by a substantial change in serum T4 and TSH concentrations.

Humans↗
PubMedDate not supplied

Isolation and identification of the polar metabolites of chlorpheniramine in the dog.

The metabolites of chlorpheniramine were isolated from dog urine. After daily repeated dosing with chlorpheniramine, [methylene-14C]chlorpheniramine maleate was given as a tracer and urine was collected until less than 1% of the labeled dose was excreted daily. An average of 54% of the oral radioactive dose was recovered in the urine. In addition to the N-demethylated metabolites, one very polar metabolite accounting for about 18% and two less polar metabolites accounting for a total of about 30% of the total urine radioactivity were isolated. Hydrolysis studies of the most polar metabolite indicated that it was a conjugate, though not a glucuronide or sulfate. The metabolite identified after hydrolysis was 3-(p-chlorobenzyl)-3-(2-pyridyl)propionic acid. One of the two less polar metabolites was identified as the corresponding alcohol. The least abundant metabolite could not be identified.

Animals↗