title: Growth patterns in selected organs of the miniature swine as determined by gross macromolecular composition.
abstract: As part of a larger study designed to characterize the early developmental stages of the Hormel-Hanford strain miniature pig, the brain, kidney, liver, pancreas, and spleen from male animals were examined for changes in RNA, DNA, and protein contents from 1 to 196 d after birth. Distinct patterns were found for changes with age in macromolecular levels. Protein levels increased from d 1 to 56 in all organs except spleen, in which little change was noted. Gel electrophoresis showed little qualitative change in the liver protein profile during this period. A fat-free, non-nucleic acid, protein-containing fraction, insoluble in hot alkali, appeared in the brain after approximately 1 wk following birth. DNA concentrations decreased markedly from d 1 to d 196 for brain, kidney, and spleen but decreased more gradually for liver and pancreas. RNA levels declined slightly or remained the same in all organs except pancreas, where a large increase occurred from d 1 to weaning (56 d). Growth proceeded in all organs by increases in cell number (hyperplasia), as evidenced by increases in total (level or concentration x organ weight) DNA, or by hypertrophy, as evidenced by increases in the ratio of protein to DNA or by a combination of both processes. Hypertrophic growth was attained by d 56 and continued to sexual maturity in all organs except spleen. Hyperplastic growth continued to sexual maturity in all organs except brain.
authors.affiliation: Food and Drug Administration, Beltsville Research Facility, Center for Food Safety and Applied Nutrition, USA.
authors.forename: L
authors.initials: L
authors.lastname: Friedman
authors.forename: D W
authors.initials: DW
authors.lastname: Gaines
authors.forename: R F
authors.initials: RF
authors.lastname: Newell
authors.forename: M C
authors.initials: MC
authors.lastname: Smith
authors.forename: R C
authors.initials: RC
authors.lastname: Braunberg
authors.forename: T J
authors.initials: TJ
authors.lastname: Flynn
authors.forename: M W
authors.initials: MW
authors.lastname: O'Donnell
mesh_terms: D000375:Aging / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000254:growth & development* / Q000378:metabolism; D001923:Brain Chemistry; D004247:DNA / Q000032:analysis / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007668:Kidney / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism; D008297:Male; D010179:Pancreas / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D012313:RNA / Q000032:analysis / Q000378:metabolism; D013154:Spleen / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism; D013552:Swine; D013556:Swine, Miniature / Q000254:growth & development* / Q000378:metabolism
chemical_list: D011506:Proteins; D012313:RNA; D004247:DNA