Estrogen desensitizes 5-HT1A receptors and reduces levels of Gz, Gi1 and Gi3 proteins in the hypothalamus

Raap, D. K.; DonCarlos, Lydia L.; García, Francisca; Muma, Nancy A.; Wolf, William A.; Battaglia, George; Kar, Louis D. Van de

doi:10.1016/s0028-3908(99)00264-6

Cited by 100 publications

(67 citation statements)

References 66 publications

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“…Estrogen increased CRH mRNA in one transvected cell line (Vamvakopoulos and Chrousos 1993) and decreased CRH mRNA expression in another cell line (Makrigiannakis et al 1996). In addition, estrogen may reduce hypothalamic CRH activity by acting on brain neurotransmitter and neuropeptide systems that regulate the HPA axis (Raap et al 2000). In vivo, some reports have found that estrogen increases CRH mRNA (Patchev and Almeida 1996;Roy et al 1999), while other reports found no effect (Redei et al 1994) and others reported a decrease in hypothalamic CRH mRNA or content (Haas and George 1988;Paulmeyer-Lacroix et al 1996).…”

Section: Discussionmentioning

confidence: 99%

Effects of Estrogen Antagonists and Agonists on the ACTH Response to Restraint Stress in Female Rats

Young

Altemus

Parkison

et al. 2001

Neuropsychopharmacology

159

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Previous studies have found that female rats are less sensitive than males to hypothalamic-pituitary-adrenal axis feedback inhibition by exogenous glucocorticoid administration. To determine whether estrogen contributesSex differences in HPA axis regulation in rodents have been demonstrated by a number of investigators, and these differences are generally attributed to activational effects of gonadal steroids on elements of the hypothalamic-pituitary-adrenal axis in females, although there is also evidence that testosterone inhibits HPA axis activity in males (Handa et al. 1994). Female rats have higher levels of total plasma corticosterone (Kitay 1963). Female rats also have higher plasma corticosterone binding globulin levels, which likely contributes to findings of similar free corticosterone levels in male and female rats. Compared with male rats, female rats also have a greater ACTH response to stress, faster onset of corticosterone secretion after stress, and a faster rate of rise of corticosterone (Le Mevel et al. 1979;Jones et al. 1972; Young 1996). Several studies suggest that estradiol plays a role in enhanced stress responses in female

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Section: Discussionmentioning

confidence: 99%

Effects of Estrogen Antagonists and Agonists on the ACTH Response to Restraint Stress in Female Rats

Young

Altemus

Parkison

et al. 2001

Neuropsychopharmacology

159

View full text Add to dashboard Cite

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“…Therefore, it can be concluded that the 5-HT 1A receptor subtype is a mediator of the antidepressant-like action of E 2 . Evidences in favor of this hypothesis are the results derived from in vitro and in vivo studies, showing that the 5-HT 1A receptor subtype is a target of estrogens and some estrogen-like compounds (Bethea et al, 1998;Biegon et al, 1983;Mize and Alper, 2000;Mize et al, 2001;Raap et al, 2000;Uphouse, 2000). Indeed, Lu and Bethea (2002) demonstrated that E 2 induces the desensitization of 5-HT 1A receptors in the DRN of monkeys.…”

Section: Discussionmentioning

confidence: 99%

Participation of the 5-HT1A Receptor in the Antidepressant-Like Effect of Estrogens in the Forced Swimming Test

Estrada‐Camarena

Fernández‐Guasti

López‐Rubalcava

2005

Neuropsychopharmacol

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The aim of the present study was to explore the possible participation of the 5-HT 1A receptor in the antidepressant-like action of two estrogenic compounds: 17b-estradiol (E 2 ) and ethynil-estradiol (EE 2 ) in the FST. Ovariectomized female Wistar rats were used in all experiments. As a positive control, the effect of the 5-HT 1A receptor agonist, 8-hydroxy-2-(di-n)-propil-aminotetraline (8-OH-DPAT; 0.0625, 0.125, 0.25 and 0.5 mg/kg) alone or in combination with WAY 100635 (0.5 and 1.0 mg/kg) was analyzed in the FST. In order to analyze the participation of the 5-HT 1A receptor in the antidepressant-like actions of estrogens, the effect of the selective antagonist WAY 100635 (0.5 and 1.0 mg/kg) in combination with E 2 (10 mg/rat) and EE 2 (5 mg/rat) was studied in the FST. In this case, WAY 100635 was administered either simultaneously with the estrogens (48 h before the FST test) or 30 min before the FST. On the other hand, a suboptimal dose of 8-OH-DPAT (0.0625 mg/kg), combined with a noneffective dose of E 2 (2.5 mg/rat) or EE 2 (1.25 mg/rat), was tested in the FST. The results showed that 8-OH-DPAT (0.25 and 0.5 mg/kg), E 2 (10 mg/rat), and EE 2 (5 mg/rat), by themselves, exerted an antidepressant-like action. The antagonist to the 5-HT 1A receptor WAY 100635, when applied together with 8-OH-DPAT or E 2 , blocked their antidepressant-like actions, but not the one induced by EE 2 . Interestingly, when the antagonist was applied 30 min before the FST, it was able to cancel the actions of EE 2 on immobility behavior, and had no effect on the actions of E 2. Finally, when a subthreshold dose of 8-OH-DPAT was combined with a noneffective dose of either E 2 or EE 2 , an antidepressant-like action was observed. The results support the notion that the 5-HT 1A receptor is one of the mediators of the antidepressant-like action of E 2 , and could indirectly contribute to the one induced by EE 2 .

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“…On the other hand, in vitro studies demonstrate that estrogens can interact, at several levels, with the dopaminergic, the noradrenergic, and the serotonergic systems (Attali et al, 1997;Bethea et al, 1998;Biegon et al, 1983;Cyr et al, 2000;McEwen, 1999;Rubinow et al, 1998). For example, estrogens can inhibit the function of the monoaminergic transporter (Ghraf et al, 1983;Michel et al, 1987;Wilson et al, 1988) and interact with either 5-HT 1A , 5-HT 2A , or b-adrenergic receptors in several brain areas (Biegon et al, 1983;Fink et al, 1996;Kendall et al, 1982;Mize and Alper, 2000;Ö sterlund et al, 1999;Raap et al, 2000;Sumner and Fink, 1995). Interestingly, estrogenic compounds modify those neurotransmitter systems that are targets of antidepressant treatments.…”

Section: Introductionmentioning

confidence: 99%

Antidepressant-Like Effect of Different Estrogenic Compounds in the Forced Swimming Test

Estrada‐Camarena

Fernández‐Guasti

López‐Rubalcava

2002

Neuropsychopharmacol

185

124

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The present study evaluated the possible antidepressant-like action of the natural estrogen 17b-estradiol (E 2 , 2.5-10 mg/rat), the synthetic steroidal estrogen ethinyl-estradiol (EE 2 , 1.25-10.0 mg/rat), and the nonsteroidal synthetic estrogen, diethyl-stilbestrol (DES, 0.25-1.0 mg/ rat) in ovariectomized adult female Wistar rats using the forced swimming test (FST). The behavioral profile induced by the estrogens was compared with that induced by the antidepressants fluoxetine (FLX, 2.5-10 mg/kg) and desipramine (DMI, 2.5-10 mg/kg). In addition, the temporal course of the antidepressant-like action of the estrogenic compounds was analyzed. FLX and DMI induced an antidepressant-like effect characterized by a reduced immobility and increased swimming for FLX and decreased immobility and increased climbing for DMI. Both E 2 and EE 2 produced a decrease in immobility and an increase in swimming, suggesting an antidepressant-like action. DES did not affect the responses in this animal model of depression at any dose tested. The time course analysis of the actions of E 2 (10 mg/rat) and EE 2 (5 mg/rat) showed that both compounds induced an antidepressant-like effect observed 1 h after their injection lasting for 2-3 days.

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Estrogen desensitizes 5-HT1A receptors and reduces levels of Gz, Gi1 and Gi3 proteins in the hypothalamus

Cited by 100 publications

References 66 publications

Effects of Estrogen Antagonists and Agonists on the ACTH Response to Restraint Stress in Female Rats

Effects of Estrogen Antagonists and Agonists on the ACTH Response to Restraint Stress in Female Rats

Participation of the 5-HT1A Receptor in the Antidepressant-Like Effect of Estrogens in the Forced Swimming Test

Antidepressant-Like Effect of Different Estrogenic Compounds in the Forced Swimming Test

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