Review: brain aromatization and other factors affecting male reproductive behavior with emphasis on the sexual orientation of rams☆

Pinckard, Kelly Lynn; Stellflug, J. N.; Resko, John A.; Roselli, Charles E.; Stormshak, F.

doi:10.1016/s0739-7240(99)00065-x

Cited by 9 publications

(3 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Alguns trabalhos têm sugerido que, em machos adultos mamíferos, o controle endócrino do comportamento sexual é feito pela testosterona, entretanto evidências indicam que estrógeno e diidrotestosterona também participam da função erétil e do comportamento sexual em algumas espécies (Henney et al, 1990;Parvizi, 2000;Pinckard et al, 2000). Henney et al (1990) descreveram que a testosterona, após ser sintetizada nos testículos liga-se à área pré-óptica do hipotálamo onde é convertida em estradiol pela enzima aromatase, com o estradiol afetando positivamente o comportamento sexual masculino.…”

Section: ____________________________________________________________unclassified

Teste Da Libido Em Touros Jovens Guzerá E Suas Associações Com Características Reprodutivas E Níveis Séricos De Testosterona

Dias¹,

Andrade

Emerick³

et al. 2009

AVS

View full text Add to dashboard Cite

Um total de 12 touros da raça Guzerá, de 24 a 34 meses de idade, avaliados andrologicamente, foram submetidos a teste da libido com o objetivo de estudar o comportamento sexual em curral, por cinco, 10 e 15 minutos de observação; e associar com características andrológicas (aspectos físicos: motilidade, vigor, turbilhonamento e concentração espermáticos, e volume do sêmen; e morfológicos: defeitos espermáticos maiores, menores e totais, do sêmen), circunferência escrotal (CE), classificação andrológica por pontos (CAP), peso corporal, idade e concentrações séricas de testosterona. Observou-se, de forma geral, baixa resposta dos animais aos testes, uma vez que menos da metade dos animais foi classificada com libido média ou alta. Verificou-se pequena variação na pontuação entre os tempos de observação, com escore 3,0 em cinco minutos e 3,3 em 15 minutos de avaliação (p>0,05). A associação entre a libido e as concentrações séricas de testosterona (0,78), reforçam o achado de influência desta característica na expressão do interesse sexual em touros jovens Guzerá.

show abstract

Section: ____________________________________________________________unclassified

Teste Da Libido Em Touros Jovens Guzerá E Suas Associações Com Características Reprodutivas E Níveis Séricos De Testosterona

Dias¹,

Andrade

Emerick³

et al. 2009

AVS

View full text Add to dashboard Cite

show abstract

“…Early treatments with aromatase inhibitors that generated rats with a bisexual phenotype (Bakker et al 1993) or reversed gonadal sex in chickens (Elbrecht & Smith 1992) exemplify the important role of aromatase during sexual development. Aromatase in the brain also modulates behaviour in adult birds and mammals (Lephart 1996;Pinckard et al 2000). Most effects of oestrogens derived from testosterone aromatization are thought to reflect specific changes in the transcription of oestrogen-dependent genes (McEwen & Alves 1999) but oestrogen can have rapid actions through non-genomic mechanisms in a variety of biological systems (Kelly & Ronnekleiv 2002) and its production can be rapidly regulated via changes in brain aromatase activity (AA) in birds (Balthazart et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Socially induced and rapid increases in aggression are inversely related to brain aromatase activity in a sex-changing fish, Lythrypnus dalli

et al. 2005

View full text Add to dashboard Cite

Social interactions can generate rapid and dramatic changes in behaviour and neuroendocrine activity. We investigated the effects of a changing social environment on aggressive behaviour and brain aromatase activity (bAA) in a sex-changing fish, Lythrypnus dalli. Aromatase is responsible for the conversion of androgen into oestradiol. Male removal from a socially stable group resulted in rapid and dramatic (> or =200%) increases in aggression in the dominant female, which will become male usually 7-10 days later. These dominant females and recently sex-changed individuals had lower bAA but similar gonadal aromatase activity (gAA) compared to control females, while established males had lower bAA than all groups and lower gAA than all groups except dominant females. Within hours of male removal, dominant females' aggressive behaviour was inversely related to bAA but not gAA. These results are novel because they are the first to: (i) demonstrate socially induced decreases in bAA levels corresponding with increased aggression, (ii) identify this process as a possible neurochemical mechanism regulating the induction of behavioural, and subsequently gonadal, sex change and (iii) show differential regulation of bAA versus gAA resulting from social manipulations. Combined with other studies, this suggests that aromatase activity may modulate fast changes in vertebrate social behaviour.

show abstract

“…Furthermore, high concentrations of androgens, principally androstenedione and testosterone, are secreted by the ovary (5). There is evidence that much of the action of androgens in the brain may be via aromatization to oestrogen and interaction with an oestrogen receptor (6, 7). Nonetheless, the involvement of the androgen receptor in the mediation of androgen action on gonadotropin secretion and/or reproductive behaviour cannot be discounted in either sex.…”

mentioning

confidence: 99%

Sex Differences in the Distribution and Abundance of Androgen Receptor mRNA‐Containing Cells in the Preoptic Area and Hypothalamus of the Ram and Ewe

Scott

Clarke²,

Rao³

et al. 2004

J Neuroendocrinology

View full text Add to dashboard Cite

Rams and ewes show a negative-feedback response to peripheral treatment with testosterone, with both sexes having a similar degree of suppression in luteinizing hormone (LH) secretion during the breeding season. At least part of the action of testosterone to suppress gonadotropin-releasing hormone/LH secretion is exerted via interaction with an androgen receptor. The distribution of androgen receptor-containing cells in the hypothalamus has been described for the ram, but similar studies have not been performed in the ewe. In the present study, we tested the hypothesis that levels of androgen receptor mRNA expression in the preoptic area and hypothalamus would be similar in rams and ewes. Perfusion-fixed brain tissue was obtained from adult Romney Marsh ewes (luteal phase) and rams during the breeding season (n = 4/sex). Androgen receptor mRNA expression was quantified in hypothalamic sections by in situ hybridization using an (35)S-labelled riboprobe and image analysis. Hybridizing cells were found in the medial preoptic area, bed nucleus of the stria terminalis, anterior hypothalamic area, ventromedial nucleus, arcuate nucleus and premamillary nucleus. The level of androgen receptor mRNA expression was higher in rams than ewes in the rostral preoptic area, caudal preoptic area and rostral portion of the bed nucleus of the stria terminalis, with no sex difference in other regions. The preoptic area and bed nucleus of the stria terminalis are important for reproductive behaviour and the sex differences in androgen receptor mRNA expression at these levels may relate to this. The high level of androgen receptor mRNA expression in the basal hypothalamus, with no sex difference, is consistent with the role of this region in the regulation of gonadotropin secretion.

show abstract

Review: brain aromatization and other factors affecting male reproductive behavior with emphasis on the sexual orientation of rams☆

Cited by 9 publications

References 75 publications

Teste Da Libido Em Touros Jovens Guzerá E Suas Associações Com Características Reprodutivas E Níveis Séricos De Testosterona

Teste Da Libido Em Touros Jovens Guzerá E Suas Associações Com Características Reprodutivas E Níveis Séricos De Testosterona

Socially induced and rapid increases in aggression are inversely related to brain aromatase activity in a sex-changing fish, Lythrypnus dalli

Sex Differences in the Distribution and Abundance of Androgen Receptor mRNA‐Containing Cells in the Preoptic Area and Hypothalamus of the Ram and Ewe

Contact Info

Product

Resources

About