Ontogeny of puromycin-sensitive and insensitive aminopeptidase activities in several subcellular fractions of the rat brain.
Puromycin-sensitive and insensitive aminopeptidase (aminopeptidase M) activities are measured in several subcellular fractions of the rat brain cortex and subcortex during the first postnatal month. Tyr-beta-naphthylamide has been used as substrate and 20 microM puromycin as selective inhibitor. We have found that puromycin-sensitive aminopeptidase activity increases twofold in the synaptosomal and mitochondrial fractions in the first 6-9 postnatal days, just during the period of axonal and dendritic growth. This enzyme also has significant age-related changes in the nuclear fraction. The developmental pattern is different, depending on the subcellular fraction analyzed. Significant developmental changes of puromycin-insensitive aminopeptidase (aminopeptidase M) are only found in the myelinic and microsomal fractions and they are less significant than those found in the puromycin-sensitive aminopeptidase. It has been suggested that these enzyme activities could be involved in processes of cell proliferation, differentiation, and maturation.
de Gandarias
J M
JM
Department of Physiology, Medical School, University of the Basque Country, Bilbao, Spain.
Irazusta
J
J
Gil
J
J
Fernández
D
D
Varona
A
A
Casis
L
L
D000704:Analysis of Variance; D000818:Animals; D018826:CD13 Antigens / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D011691:Puromycin / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions / Q000201:enzymology*
D011691:Puromycin; D018826:CD13 Antigens