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Polyamine metabolism in regenerating livers from normal and hypocalcemic rats
Author(s) -
Walker P. Roy,
Whitfield James F.,
Sikorska Marianna
Publication year - 1978
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040940111
Subject(s) - spermidine , putrescine , ornithine decarboxylase , polyamine , spermine , medicine , endocrinology , chemistry , metabolism , hepatectomy , liver regeneration , dna synthesis , biochemistry , enzyme , biology , dna , regeneration (biology) , microbiology and biotechnology , surgery , resection
There is a marked increase in the concentration of putrescine during the first ten hours following partial hepatectomy in rats. The concentration of spermidine also increases but to a smaller degree. Putrescine levels return to normal between 10 and 24 hours after the operation, whereas the increased spermidine level is maintained. The production of putrescine and spermidine appears to be initiated by the induction of ornithine decarboxylase which shows a single peak of activity at four hours after hepatectomy. The activity of S‐adenosylmethionine decarboxylase shows little change following hepatectomy. The changes in polyamine levels and the activities of the enzymes of polyamine metabolism are not affected by thyroparathyroidectomy 72 hours prior to hepatectomy. Thus although these hypocalcemic conditions considerably reduce and delay DNA synthesis and mitosis, the prereplicative changes in polyamine metabolism still occur. These data suggest that the hepatocytes in hypocalcemic animals have become activated and moved to an advanced stage of prereplicative development before being blocked.