Effect of steroid hormone deprivation on the expression of ecto-ATPase in distinct brain regions of female rats

Abundant evidence indicates that ATP and adenosine act as neurotransmitters or co-transmitters, influencing nerve cell physiology in various ways. The refore, regulation of ATP-metabolizing enzymes is essential for the normal development and function of neuronal tissue. In the present study we have e xamined the effect of gonadal (OVX) or adrenal (ADX) steroid hormone depriv ation on the activity and expression of synaptic membrane ecto-ATPase in th ree extrahypothalamic brain areas of female rats, primarily not associated with reproductive function. It was shown that OVX significantly increased e cto-ATPase activity and the relative abundance of this enzyme in the hippoc ampal (Hip) and caudate nucleus (CN), but not in brain stem (BS) membrane p reparations. ADX was followed by an upregulation of the enzyme activity and its relative abundance in all the brain areas investigated. The highest en zyme 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 expr ession 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.