title: Growth of rat parotid glands is inhibited by liquid diet feeding.
abstract: This study investigated how liquid diet feeding affects the growth of parotid glands. We weaned 21-day-old rats and thereafter fed them a pellet diet (control group) or a liquid diet (experimental group) for 0, 1, 2, 4, or 8 weeks. Their parotid glands were excised, weighed, examined, and tested for 5-bromo-2'-deoxyuridine (BrdU) and cleaved caspase-3 (Casp-3) as markers of proliferation and apoptosis, respectively. Parotid gland weights were consistently smaller in experimental animals than in controls. Morphometrical analysis showed that control group acinar cells increased in area during the experiment, but experimental group acinar cells were almost unchanged. Labeling indices of BrdU in acinar cells in both groups declined during the experiment, but were consistently lower in the experimental group than in controls. Casp-3-positive acinar cells were rare in both groups, which consistently express significantly similar Casp-3 levels. Ultrastructurally, terminal portions of the experimental parotid glands consisted of a few acinar cells that were smaller than those in controls. Control acinar cells showed mitotic figures within short experimental periods, but not in experimental glands. These observations indicate that liquid diet feeding inhibits growth of parotid glands in growing rats through suppression of growth and proliferation of individual acinar cells, but not through apoptosis.
authors.affiliation: Department of Oral Functional Anatomy, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Electronic address: tshigeru@den.hokudai.ac.jp.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Oral Functional Anatomy, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Uekita
authors.affiliation: Department of Oral Functional Anatomy, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kato
authors.affiliation: Department of Oral Functional Anatomy, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Department of Oral Functional Anatomy, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Domon
mesh_terms: D061354:Acinar Cells / Q000648:ultrastructure*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000096:biosynthesis; D049109:Cell Proliferation / Q000187:drug effects*; D004032:Diet; D008297:Male; D010306:Parotid Gland / Q000187:drug effects* / Q000254:growth & development; D051381:Rats
chemical_list: D053148:Caspase 3
keywords: Acinar cell; Apoptosis; Cell proliferation; Growth; Liquid diet; Parotid gland