title: Reproduction of the tundra vole (Microtus oeconomus) with dietary phytosterol supplement.
abstract: Phytosterols (PS) are plant-derived compounds with estrogenic activity in vitro and beneficial effects on the serum lipid profile in vivo. In nature, PS exposure can derive from pulp mill effluents. The effects of a pulp-mill derived PS mixture on the reproduction, endocrine variables and enzyme activities of the tundra vole (Microtus oeconomus) were investigated in a two-generation study. The cumulative food intake of PS-treated females was higher than in the control group supporting previous results on the effects of PS on food consumption in rodents. 85% of the PS treated pairs reproduced, but the figure was only 60% for the control pairs. The plasma and testicular testosterone concentrations were lower in the adult PS males, but the PS-treated male offspring had higher testicular testosterone concentrations than their controls. In the female offspring, the liver lipase activity was higher in the PS-treated group, which could be a result of decreased cholesterol absorption in the gut. Chronic PS treatment increased the reproduction probability of the species and had a potential effect on the sex steroid hormones of maturing offspring, which could have applications in environmental monitoring.
authors.affiliation: University of Joensuu, Department of Biology, PO Box 111, FIN-80101 Joensuu, Finland. pniemine@cc.joensuu.fi
authors.forename: P
authors.initials: P
authors.lastname: Nieminen
authors.forename: A-M
authors.initials: AM
authors.lastname: Mustonen
authors.forename: P
authors.initials: P
authors.lastname: Päiväläinen
authors.forename: J V K
authors.initials: JV
authors.lastname: Kukkonen
mesh_terms: D000284:Administration, Oral; D000821:Animal Feed; D000818:Animals; D003411:Arvicolinae / Q000502:physiology*; D002784:Cholesterol / Q000378:metabolism; D005260:Female; D007220:Industrial Waste; D008049:Lipase / Q000494:pharmacology; D008099:Liver / Q000201:enzymology; D008297:Male; D010840:Phytosterols / Q000494:pharmacology*; D012098:Reproduction / Q000187:drug effects*; D013739:Testosterone / Q000032:analysis*
chemical_list: D007220:Industrial Waste; D010840:Phytosterols; D013739:Testosterone; D002784:Cholesterol; D008049:Lipase