title: Effects of timing and dose of vitamin A on tissue retinol concentrations and antibody production in the previously vitamin A-depleted rats.
abstract: The effect of retinol repletion in previously vitamin A-depleted Lewis rats on antibody production to pneumococcal polysaccharide (SSS-III) was studied. When vitamin A-depleted rats were given either 0.35 mumol (0.1 mg) or 5.2 mumol (1.5 mg) retinol, plasma retinol became normal within 8 h. Liver and lymphoid-organ retinol concentrations were normalized by 1 d after repletion with 5.2 mumol but not 0.35 mumol retinol. Antibody production to SSS-III was compared after administering 5.2 mumol retinol either as a divided dose (half given 4 d before and half given on the day of immunization) or as a single dose concurrent with immunization. Vitamin A-depleted rats produced very little SSS-III-specific antibody. The divided dose of retinol consistently restored anti-SSS-III production whereas the single concurrent dose was less effective despite equal effects on tissue retinol concentrations. Interestingly, normalization of plasma retinol was not always a good predictor of the immune response to pneumococcal polysaccharide.
authors.affiliation: Division of Nutrition, Medical College of Pennsylvania, Philadelphia 19129.
authors.forename: A M
authors.initials: AM
authors.lastname: Pasatiempo
authors.forename: M
authors.initials: M
authors.lastname: Abaza
authors.forename: C E
authors.initials: CE
authors.lastname: Taylor
authors.forename: A C
authors.initials: AC
authors.lastname: Ross
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000276:immunology; D002452:Cell Count; D004305:Dose-Response Relationship, Drug; D007114:Immunization; D007700:Kinetics; D008297:Male; D009994:Osmolar Concentration; D011135:Polysaccharides, Bacterial / Q000276:immunology; D051381:Rats; D011917:Rats, Inbred Lew; D013154:Spleen / Q000473:pathology; D013997:Time Factors; D014801:Vitamin A / Q000097:blood / Q000378:metabolism / Q000494:pharmacology*; D014802:Vitamin A Deficiency / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial; C026604:pneumococcal polysaccharide, type III; D014801:Vitamin A