US EPA

2169910 

Journal Article 

Enzymatic imprinting in adult animals 

Khudolei, VV; Mizgirev, IV; Maiorova, IG 

1990 

Yes 

Bulletin of Experimental Biology and Medicine
ISSN: 0007-4888
EISSN: 1573-8221 

109 

6 

724-727 

English 

WOS:A1990ET45200011 

Activation of the microsomal monooxygenase system in the liver by various inducers leads to changes in xenobiotic biotransformation [6]. The specific effect of the inducers acting on adult animals is short in duration, unlike that in fetuses and newborn animals, in which increased enzyme activity is maintained for a long time or even throughout life. This phenomenon, which has been called enzymic imprinting [4, 5], has been observed following administration of steroid hormones [11], phenobarbital [9, 15], 16-alpha-isothiocyanopregnenolone-3-acetate [4], tetrachlorodibenzo-p-dioxine [12], and Aroclor 1254 [3]. The existence of this phenomenon is due both to increased sensitivity of fetuses and newborn animals to endogenous or exogenous inducers and to the fact that they contain specific mechanisms of fixation of altered enzyme activity induced by these factors. Thus enzymic imprinting is an essential component of the adaptive strategy of the developing organism, forming, along with genetic factors, its individual sensitivity to unfavorable environmental influences. The mechanism of fixation of the level of enzyme activity, modified by the influence of inducers, may be closely connected with intensive proliferation processes taking place in fetal and neonatal liver tissues. It can accordingly be postulated that artificial enhancement of proliferation in the adult liver as a result of partial hepatectomy will modify the conditions that enable fetal and neonatal tissues to fix a level of enzyme activity modified through the action of inducers. The aim of this investigation was to test this hypothesis experimentally. 

IMPRINTING; ENVIRONMENT; PROLIFERATION; HEPATECTOMY