Premium
GLYCOGEN SYNTHESIS AND BREAKDOWN IN RAT LIVER AT BIRTH
Author(s) -
Dawkins M. J. R.
Publication year - 1963
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.1963.sp001664
Subject(s) - glycogen , medicine , endocrinology , glycogen synthase , glucose 6 phosphatase , biology , alkaline phosphatase , phosphatase , glycogenesis , fetus , glycogen debranching enzyme , enzyme , chemistry , pregnancy , biochemistry , genetics
Glycogen appears in rat liver in large amounts just before term and disappears rapidly in the first 12 hr. after birth. The liver of the fœtus is well equipped for glycogen synthesis since glycogen synthetase activity and glucose‐6‐phosphate concentrations are high. After birth there is no change in glycogen synthetase activity, but glucose‐6‐phosphate levels fall rapidly to low levels. Of the enzymes involved in the breakdown of glycogen to glucose‐6‐phosphate and its subsequent metabolic fate, only one, glucose‐6‐phosphatase shows any marked change in activity after birth. Glucose‐6‐phosphatase activity is very low in fœtal liver and rises rapidly after birth to levels several times higher than in adult liver. It is suggested that the low glycogen levels in rat liver after birth are at least in part due to this great increase in glucose‐6‐phosphatase activity. The results are discussed in relation to the problem of the regulation of blood glucose levels in the newborn animal.