Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 1999
Publication Date: March 15, 2000
Citation: Hunt, C.D., Keehr, K.A. 2000. Apparent beneficial effects of dietary boron on rat reproduction are modified by dietary erythritol [abstract]. The Federation of American Societies for Experimental Biology Journal. 14:A478. Technical Abstract: Dietary boron is apparently essential for embryological development in lower vertebrate species. Boron essentiality for a higher animal model was examined in a 2 x 2 factorially-arranged experiment with weanling Sprague- Dawley female rats (13/treatment) fed a boron low basal diet (~0.1 mg B/kg) supplemented with boron (as orthoboric acid) at 0 (0B) or 2 (2B) mg/kg and a boron-binding biomolecule, erythritol (E; forms boro mono- or diesters through the cis-diol on the furanoid ring), at 0 (0E) or 5 (5E) mg/kg for a E:boron molar ratio of 4 in the 0B/5E group. Females were bred at 71 d of age with similarly fed males (5/treatment), killed on gestational day 19, and examined for pregnancy status. The overall pregnancy rate was rather low (40%) but highest in the 2B/0E group (54%) and lowest in the 2B/5E group (36%). In an interaction (p <0.001), physiologic amounts of boron decreased the number of fetal resorptions (FR) per litter (0.29 vs. 0.80) in the absence of E. However, boron increased FR (1.75 vs 0.00) in the presence of E. Fetal thoracic vertebral morphologic maturation was slower in litters fed physiologic amounts of boron (p < 0.02) but similar to that observed in commercial chow (~12 mg B/kg)-fed rats (in a parallel study). Neither boron nor E affected fetal body weight. Boron increased dam white blood cell concentrations (million cells/mL) in the presence of E only (7.86 vs. 5.38; BxE: p <0.02). The findings suggest a reproductive role for boron that is influenced by dietary E. Erythritol should be examined further to develop a model system useful in elucidating the molecular mechanism(s) whereby boron beneficially influences many aspects of physiology.