Estrogen and Parkinson s disease

Abstract

Female sex hormones, and more specifically estrogen, can have biochemical and behavioral effects on the dopaminergic system. The effects of estrogen on the dopaminergic system can be classified as either neuroprotective or symptomatic. The neuroprotective effects refer to the ability of estrogen to prevent or modulate insults to the dopaminergic system and therefore to alter the natural history of disease processes affecting the dopaminergic circuitry in the brain. With regards to the symptomatic effects, support for both suppressive and enhancing effects has been documented in humans and laboratory animals. The pre-clinical literature for neuroprotective and symptomatic effects of estrogen on the mesostriatal dopaminergic system forms the basis for studies on the influence of estrogen on the prevalence, disease progression, clinical signs, and medication effects of Parkinson's disease and other movement disorders. Understanding the role of estrogen in modulating the dopaminergic system will allow clinicians to tailor therapies for women with Parkinson's disease and optimize therapies for menstrually related symptom fluctuations. Such clarifications may also guide recommendations on the use of postmenopausal hormonal replacement therapy in women with Parkinson's disease or those genetically at risk.

Effects of Long‐Term Hormone Treatment and of Tibolone on Monoamines and Monoamine Metabolites in the Brains of Ovariectomised, Cynomologous Monkeys

“…The effects of oestradiol on the detection of dopaminergic neurones in the substantia nigra have also been reported (36), as well as the effects on dopaminergic fibres and transmission in the caudate (37–39). These effects may underlie sex differences in psychomotor performance and the aetiology and treatment of Parkinson's disease (40, 41). The effects of oestradiol on dopaminergic, noradrenergic and serotonergic activity in the mediobasal hypothalamus have also been described, and there is evidence that the noradrenergic and serotonergic effects may underlie the well‐documented effects of ovariectomy and hormone therapy on vasomotor symptoms (42–44).…”

Evaluation of animal models of Parkinson's disease for neuroprotective strategies

“…PD incidence is higher in men than in women and estrogen replacement therapy is associated with delayed age of onset of PD (Kompoliti, 2003). In fact, in animal models of PD estrogen administration significantly attenuates the degree of striatal dopamine depletion induced by MPTP, 6-OHDA and methamphetamine (Dluzen, 2000).…”

Contribution of estrogen receptors alpha and beta to the effects of estradiol in the brain

“…Estrogens may be involved in gender differences observed in cognitive functions and in the prevalence and symptomatology of neurodegenerative and mental diseases [1,[10][11][12][13]. Indeed, beneficial effects of estrogens are reported in several mental, namely schizophrenia and depression [1,[14][15][16] and neurodegenerative diseases such as Alzheimer's and Parkinson's diseases as well as multiple sclerosis, and ischemic stroke [1,[17][18][19][20][21].…”