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CHANGES IN THE COMPOSITION OF RABBIT LIVER AND OF LIVER MICROSOME FRACTIONS FOLLOWING BIRTH
Author(s) -
Lathe G. H.,
Ricketts T. R.
Publication year - 1964
Publication title -
quarterly journal of experimental physiology and cognate medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0033-5541
DOI - 10.1113/expphysiol.1964.sp001707
Subject(s) - microsome , phospholipid , endocrinology , medicine , composition (language) , chemistry , biology , rna , biochemistry , enzyme , linguistics , philosophy , membrane , gene
The conditions for maximal recovery of the microsome fraction from rabbit liver homogenates have been established. Glucose‐6‐phosphatase is a poor index of the recovery of microsomal material from a cell sap microsome fraction mixture, as it is more rapidly sedimented than RNA and total protein. The sedimentation of glucose‐6‐phosphatase parallels that of microsomal phospholipid. The changes in composition of neonatal rabbit livers and liver microsome fractions were determined. The concentrations of dry matter, phospholipid and RNA are relatively constant during neonatal development, but total lipid, which is about 15–20 per cent of wet weight at birth, drops to adult levels in about 10 days. Total nitrogen increases from about 65 per cent of adult values at birth to adult values during the month after birth. The number of nuclei and the liver DNA content per unit wet weight of liver drops by about two‐thirds during the first week after birth. This is probably due to the loss of erythropoietic cells. The mean DNA per liver nucleus alters little in the first 2 weeks after birth and is then about 20 per cent below the adult value. The microsomal RNA and nitrogen concentrations are relatively constant during neonatal development. The main microsomal change is an increase of phospholipid, adult concentrations being reached 2–4 weeks after birth.