Effects of Estrogen and Progesterone on Catalepsy andMotor and Balance Impairment Classified asHaloperidol-induced Extrapyramidal Disorders

Aims:

 Various evidences have shown the effect of ovarian hormones on locomotor activities and catalepsy induced by a variety of stimuli. The aim of this study was to evaluate the effects of estrogen and progesterone on catalepsy and motor and balance impairment classified as haloperidol-induced extrapyramidal disorders.

Materials and Methods:

 The current experimental study was performed on 96 female Wistar rats (180-200g). These rats were randomly divided into 16 groups (n=6). Prior to administration of haloperidol, the rats were pretreated with flutamide (10mg/kg, i.p.), estrogen (1mg/kg 17 β-estradiol, s.c.), and/or progesterone (1mg/kg, i.p.) for 1 day or 7 consecutive days. The effects of estrogen and progesterone on haloperidol-induced catalepsy and motor impairment were assessed by a bar test and a rotarod performance test, respectively. Data were analyzed by SPSS 22 software using ANCOVA and Tukey test.

Findings:

 One to 7-day treatment with estrogen had a protective effect on haloperidol-induced extrapyramidal disorders such that it significantly improved catalepsy and motor impairment in the rats and restored and normalized their motor levels. However, the progesterone administration did not represent significant effects in improving extrapyramidal symptoms and a slight improvement was achieved. The co-administration of flutamide significantly reduced the protective effect of estrogen on catalepsy and motor balance impairment induced by haloperidol.

Conclusion:

 The deficiency of ovarian hormones increases catalepsy; however, this disorder is more likely to occur due to estrogen insufficiency. Hence, progesterone plays a little role in it. Moreover, the anti-cataleptic effect of ovarian hormones is exerted through affecting androgenic receptors.