title: Relative bioavailability of zinc using weight gain of rats.
abstract: Weanling rats were fed semi-purified diets with varying zinc levels in order to derive new measures of relative bioavailability of zinc (RBAZ). The various measures for RBAZ were slope-ratio assays of weight gain, total liver zinc and total femur zinc along with five alternative measures developed from sigmoidal curves for weight gain estimated by a non-linear, least-squares curve fitting computer program. The slopes of weight gains explained a higher proportion of the true measure than similar slopes of femurs or livers as indicated by R2. The 95% confidence intervals of ratios were narrowest for weight gain assays. Four of the five alternative methods had RBAZ similar to the RBAZ of slope-ratio weight gain assays. These new methods provided a diversity of information and allowed more information to be obtained than from slope-ratio assays alone.
mesh_terms: D000818:Animals; D001682:Biological Availability; D001835:Body Weight / Q000187:drug effects*; D004032:Diet; D005269:Femur / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D012044:Regression Analysis; D015032:Zinc / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D015032:Zinc