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Effect of Steroid Hormone Deprivation on the Expression of Ecto-ATPase in
Distinct Brain Regions of Female Rats
N. Nedeljkovic1,2, V. Djordjevic1, A. Horvat1,
G. Nikezic1, D.T. Kanazir1
1Laboratory of Molecular Biology and Endocrinology, Vinca Institute of
Nuclear Sciences and 2Department of General Physiology and
Biophysics, Faculty of Biology, University of Belgrade, Yugoslavia
Received July 29, 1999
Accepted January 19, 2000
Summary
Abundant evidence indicates that ATP and adenosine act as
neurotransmitters or co-transmitters, influencing nerve cell physiology in
various ways. Therefore, regulation of ATP-metabolizing enzymes is essential for
the normal development and function of neuronal tissue. In the present study we
have examined the effect of gonadal (OVX) or adrenal (ADX) steroid hormone
deprivation on the activity and expression of synaptic membrane ecto-ATPase in
three extrahypothalamic brain areas of female rats, primarily not associated
with reproductive function. It was shown that OVX significantly increased
ecto-ATPase activity and the relative abundance of this enzyme in the
hippocampal (Hip) and caudate nucleus (CN), but not in brain stem (BS) membrane
preparations. ADX was followed by an upregulation of the enzyme activity and its
relative abundance in all the brain areas investigated. The highest enzyme
activity and the most profound effects of OVX and ADX were detected in the CN.
The results obtained indicate that ADX and OVX upregulate the expression of
ecto-ATPase, potentiating the production of adenosine in synaptic cleft thus
modulating the activity of numerous neurotransmitter systems in distinct areas
of the CNS.
Key words
Ecto-ATPase · Ovariectomy ·
Adrenalectomy · Extracellular nucleotides ·
Rat brain
Reprint requests
N. Nedeljkovic, Vinca Institute of Nuclear Sciences,
Laboratory of Molecular Biology and Endocrinology, P.O. Box 522, 11001 Belgrade,
Yugoslavia. Fax: + 381 11 455 561; E-mail: nnedel@RT270.vin.bg.ac.yu
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