title: Short-term effects of nicotine on bone and calciotropic hormones in adult female rats.
abstract: This study assessed the effects of two months nicotine treatment on bone formation and resorption end-points in adult, female rats. In addition, the concentrations of calciotropic hormones which included parathyroid hormone, calcitonin, 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D in rats (7 months old) were determined. All animals received either saline (n = 7/group), nicotine (3.0 mg/kg/day) (n = 7/group) or nicotine (4.5 mg/kg/day) (n = 7/group) via subcutaneous implantation of osmotic minipumps containing either saline or nicotine for a period of two months. Serum, right tibia, left femur and lumbar vertebra (3-5) were collected for determination of hormonal concentrations as well as various parameters, including histomorphometry, bone mineral density, bone mineral content and vertebral strength. Although nicotine-treated rats showed a lower level of 25-hydroxyvitamin D [54.4 +/- 3.1 ng/ml for the 3.0 mg/kg/day and 55.8 +/- 2.8 for the 4.5 mg/kg/day group] (mean +/- S.E.M.) as compared to controls (74.8 +/- 2.8 ng/ml) (P < 0.01, Newman-Keuls test), no significant difference could be detected for the levels of the remaining hormones. Similarly, no statistical differences were detected on histomorphometric end-points, bone mineral density, bone mineral content and vertebral strength of rats. We conclude that, in spite of lowering serum 25-hydroxyvitamin D by about 30%, nicotine administration of two months duration does not alter bone mass, strength or formation and resorption end-points.
authors.affiliation: Department of Oral Biology, University of Nebraska Medical Center (UNMC), College of Dentistry, Lincoln 68583, USA.
authors.forename: Y K
authors.initials: YK
authors.lastname: Fung
authors.forename: M G
authors.initials: MG
authors.lastname: Mendlik
authors.forename: M C
authors.initials: MC
authors.lastname: Haven
authors.forename: M P
authors.initials: MP
authors.lastname: Akhter
authors.forename: D B
authors.initials: DB
authors.lastname: Kimmel
mesh_terms: D000818:Animals; D001862:Bone Resorption / Q000378:metabolism*; D002116:Calcitonin / Q000097:blood; D005260:Female; D006728:Hormones / Q000097:blood*; D006887:Hydroxycholecalciferols / Q000097:blood; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D010281:Parathyroid Hormone / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism; D013997:Time Factors
chemical_list: D006728:Hormones; D006887:Hydroxycholecalciferols; D018722:Nicotinic Agonists; D010281:Parathyroid Hormone; D009538:Nicotine; D002116:Calcitonin