Growth patterns in selected organs of the miniature XXXX as determined by gross macromolecular composition.

@entity1184 @entity1707 @entity1373 @entity5072
As part of a larger study designed to characterize the early developmental stages of the Hormel-Hanford strain miniature @entity1707 , 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 ( @entity1373 ), as evidenced by increases in total (level or concentration x organ weight) DNA, or by @entity1184 , as evidenced by increases in the ratio of protein to DNA or by a combination of both processes. @entity1184 growth was attained by d 56 and continued to sexual maturity in all organs except spleen. @entity5072 growth continued to sexual maturity in all organs except brain.
