title: Relation between technetium 99m-methoxyisobutylisonitrile accumulation and multidrug resistance protein in the parathyroid glands.
abstract: Technetium 99m ((99m)Tc)-methoxyisobutylisonitrile (MIBI) scintigraphy has been reported to be a useful method for visualizing the parathyroid glands for the diagnosis of hyperparathyroidism. Some drug metabolism transporters, such as p-glycoprotein (P-GP) or multidrug resistance-associated protein (MRP), are believed to be involved with one mechanism of (99m)Tc-MIBI accumulation in the parathyroid glands. We analyzed the expression of P-GP and MRP in 40 parathyroid glands from eight patients with primary hyperparathyroidism and six patients with secondary hyperparathyroidism using an immunohistochemical procedure. These patients underwent (99m)Tc-MIBI scintigraphy and thallium 201 ((201)Tl)/(99m)Tc subtraction scintigraphy preoperatively. We investigated the relation between the scintigraphic images and the expression of P-GP and MRP. The positive findings of (99m)Tc-MIBI accumulation in the hyperfunctioning parathyroids were increased significantly. There was a significant difference between the expression of P-GP and the (99m)Tc-MIBI scintigraphy findings. High expression of P-GP in parathyroid cells resulted in the negative image of (99m)Tc-MIBI, and low or no expression of P-GP made the image positive. There was no significant difference between the expression of MRP and the (99m)Tc-MIBI scintigraphic imaging. The (99m)Tc-MIBI image was also related to the weight of the parathyroid glands but not to the type of the parathyroid cells. Based on these clinical findings, we can hypothesize that P-GP functions as a drug transporter not only for chemotherapeutic agents but also for (99m)Tc-MIBI.
authors.affiliation: Department of Urology, Asahikawa Medical College, Midorigaoka Higashi 2-1-1-1, Asahikawa 078-8510, Japan. syama@asahikawa-med.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Sunao
authors.initials: S
authors.lastname: Yachiku
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Shigeo
authors.initials: S
authors.lastname: Kaneko
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nishihara
authors.forename: Daisuke
authors.initials: D
authors.lastname: Niibori
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Shuke
authors.forename: Tamio
authors.initials: T
authors.lastname: Aburano
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000032:analysis*; D006801:Humans; D006961:Hyperparathyroidism / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D006962:Hyperparathyroidism, Secondary / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000032:analysis*; D010280:Parathyroid Glands / Q000737:chemistry* / Q000000981:diagnostic imaging* / Q000601:surgery; D016105:Parathyroidectomy; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D013667:Technetium / Q000032:analysis; D017256:Technetium Tc 99m Sestamibi / Q000032:analysis*; D013794:Thallium Radioisotopes / Q000032:analysis
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D013667:Technetium; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes