ACETYLCHOLINESTERASE ACTIVITY IN THE WHOLE BLOOD OF FEMALE
WISTAR RATS OF DIFFERENT AGES
ATIVIDADE DA ACETILCOLINESTERASE DO SANGUE TOTAL DE RATAS
WISTAR DE DIFERENTES IDADES
Danieli Brolo Martins1, Cinthia Melazzo Mazzanti1, Raqueli Teresinha França1, Marciélen
Pagnoncelli1, Márcio Machado Costa1, Estevan Souza Martins1, Thais Rapachi Mann1,
Diandra Visentini1, Francieli Comin Flores1, Guilherme Lopes Dornelles1, Carlos H. Amaral2,
Sonia Terezinha dos Anjos Lopes1
Summary
The aim of the present study was to investigate the effects of 17- β estradiol in the
acetylcholinesterase activity in the whole blood of ovariectomized female wistar rats of
different ages. Adult and middle-aged rats were randomly assigned into three experimental
groups of each age (n=6), where control groups consisted of female rats in proestrus,
ovariectomized rats without hormone therapy reposition, and ovariectomized rats treated with
17-β estradiol for 30 continuous days. Adult ovariectomized animals supplemented with 17-β
estradiol showed an increase of AChE activity while the middle-aged ovariectomized animals
without estrogen replacement had a decreased in the enzyme activity. It is possible that this
hormone can influence the local immune response.
Keywords: hormone therapy reposition, estrogen, blood cells, immune system.
Resumo
O objetivo deste trabalho foi investigar os efeitos do 17- β estradiol na atividade da
acetilcolinesterase no sangue total de ratas wistar ovariectomizadas de diferentes idades.
Ratas adultas e de meia-idade foram separadas ao acaso de acordo com a idade em três grupos
experimentais (n=6), onde os grupos controle consistiram de ratas em proestro, ratas
ovariectomizadas sem reposição hormonal e ratas ovariectomizadas tratadas com 17-β
estradiol por 30 dias contínuos. Os animais adultos ovariectomizados suplementados com 17β estradiol mostraram um aumento da atividade da AChE enquanto que os animais
ovariectomizados de meia idade sem reposição estrogênica tiveram uma diminuição na
atividade da enzima. É possível que este hormônio possa influenciar a resposta imune local.
Palavras-chave: terapia de reposição hormonal, estrogênio, células sanguíneas, sistema
imune
The enzyme acetylcholinesterase (AChE; E.C. 3.1.1.7) found in the cholinergic
terminal is a specific choline esterase, hydrolyzing predominantly choline esters
(acetylcholine - ACh) and characterized by high levels in brain, nerve, red blood cells (DAS,
2007).
The 17-β estradiol can influence so many aspects of central nervous system (CNS) and
immune function, and understand the cellular and molecular mechanisms that underlie these
protective actions is essential to preventing the deleterious consequences of prolonged
hypoestrogenicity and to improving women’s health (WISE et al., 2001). The mechanism of
neuroprotection, however, remains to be understood (CIMAROSTI et al., 2005; SALES et al.,
2010). Considering this, this study aimed to evaluate the effects among the estrogenic
reposition in parameters related to the acetylcholinesterase activity in whole blood from adult
1
Departamento de Pequenos Animais, Hospital Veterinário, Universidade Federal de Santa Maria, CEP 97105900. Email para correspondência: [email protected]
2
Universidade Federal da Paraná.
and middle-aged female wistar rats.
Thirty six female Wistar rats were used, where 18 animals were 5 months-old (adults)
and the others 18 were 10 months-old (middle-aged). Control groups underwent a sham
surgery, the other groups underwent gonad removal. Adult and middle-aged rats were
randomly assigned into three experimental groups of each age (n=6), where control groups
consisted of female rats in proestrus (GI), ovariectomized rats without estrogen therapy
reposition (GII), and ovariectomized rats treated with 17-β estradiol (GIII). GI and GII groups
received just canola oil vehicle, while GIII received 0.1µg/g of body weight of 17-β estradiol
for 30 days.
The AChE enzymatic assay was determined by the method of Ellmann et al. (1961),
modified by Worek et al. (1999). The statistical analysis used was one-way ANOVA, followed
by Duncan’s multiple range tests. All the data are expressed as the mean ± standard error.
Differences were considered significant when the probability was p < 0.05.
Post hoc comparisons by Duncan’s multiple range test revealed that the AChE activity
in whole blood of the adult animals was significantly increased in the group III (p < 0.05)
when compared to the group I and II (Figure 1). The AChE activity in whole blood of the
middle-aged animals was significantly decreased in the group II (p < 0.05) when compared to
the group I. Although, the group III didn’t show any significant alteration when compared to
the group I or group II (Figure 2).
About the fraction of whole blood, we observed that administration of 17-β estradiol
normalized AChE activity to levels similar to those showed by the control group.
References
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2