title: P-glycoprotein polymorphism in hypo- and hyper-thyroidism patients.
abstract: P-glycoprotein (Pgp) is encoded by the multidrug resistance gene (MDR1) in humans and is the product of MDR1. It is expressed in various tissues and is related to drug distribution in intestinal erythrocytes, capillary endotel of brain, proximal tubules cells of kidneys and liver canalicular cells. Expression of Pgp is affected by Pgp polymorphism, and exon 26 C3435T polymorphism is the most common one. It has been thought that expression of Pgp is high in C-allele subjects and this situation is responsible for the resistance against some drugs and substances. Pgp may have a role in the distribution of thyroid hormones, drugs used for hypo- and hyperthyroidism and the resistance occurred. For this purpose possible relationship between T and C alleles and frequency of Pgp polymorphism as well as thyroid hormone distribution in patients with hypo- and hyperthyroidism was investigated. Thirty five hyperthyroidism patients diagnosed as Graves' disease, 78 hypothyroidism patients diagnosed as Hashimoto's thyroiditis and 100 healthy volunteers were included in the study. According to the results obtained no statistically significant difference was found in Pgp C3435T polymorphism between hypo- and hyperthyroidism patients. In addition, the serum free T3 levels of hyperthyroidism patients with C alleles was higher than those of subjects with T alleles. No statistically significant difference was seen in the CC, CT and TT genotype frequencies between the patients and control groups. In conclusion, it seems that Pgp polymorphism is not a predictor factor for the occurrence of hypo- and hyperthyroidism. There is a significant relationship between Pgp and the elevated serum free T3 levels of hyperthyroidism patients, and further research will help understand this situation.
authors: Faculty of Medicine, Department of Physiology, University of Pamukkale, Denizli, 20070, Turkey. gturgut@pau.edu.tr
authors: Günfer
authors: G
authors: Turgut
authors: Mehmet
authors: M
authors: Baştemir
authors: Sebahat
authors: S
authors: Turgut
authors: Fulya
authors: F
authors: Akin
authors: Raziye
authors: R
authors: Kursunluoglu
authors: Bünyamin
authors: B
authors: Kaptanoğlu
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism; D000483:Alleles; D005091:Exons; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006111:Graves Disease / Q000235:genetics / Q000378:metabolism; D050031:Hashimoto Disease / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006980:Hyperthyroidism / Q000235:genetics* / Q000378:metabolism; D007037:Hypothyroidism / Q000235:genetics* / Q000378:metabolism; D011110:Polymorphism, Genetic
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1