RAM EFFECT ON ESTRUS BEHAVIOR, OVARIAN STRUCTURE AND STEROID HORMONE LEVELS IN OSSIMI EWES TREATED WITH PROSTAGLANDIN F2α FOR ESTRUS SYNCHRONIZATION

Objective: Although it is widely assumed that men’s sexual desire and interest in casual sex (i.e., sociosexual orientation) are linked to steroid hormone levels, evidence for such associations is mixed. Methods: We tested for both longitudinal and cross-sectional relationships between salivary testosterone, cortisol, reported sexual desire and sociosexuality in a sample of 61 young adult men, each of whom was tested weekly on up to five occasions. Results: Longitudinal analyses showed no clear relationships between steroid hormones and self-reported sexual desire or sociosexual orientation. Cross-sectional analyses showed no significant associations between average hormone levels and self-reported sexual desire. However, some aspects of sociosexuality, most notably desire for casual sex, were related to men’s average hormone levels. Men with higher average testosterone reported greater desire for casual sex, but only if they also had relatively low average cortisol levels. Conclusions: Our results support a Dual Hormone account of men’s sociosexuality, in which the combined effects of testosterone and cortisol predict the extent of men’s interest in casual sex. However, we did not detect compelling evidence for an association of within-subject hormone shifts and sexual desire or sociosexual orientation.

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Short oestrous cycles in sheep during anoestrus involve defects in progesterone biosynthesis and luteal neovascularisation

Reproduction ◽

10.1530/rep-13-0400 ◽

2014 ◽

Vol 147 (3) ◽

pp. 357-367 ◽

Cited By ~ 10

Author(s):

H M Brown ◽

C Fabre Nys ◽

J Cognié ◽

R J Scaramuzzi

Keyword(s):

Luteal Phase ◽

Regulatory Protein ◽

Prostaglandin F2α ◽

Significant Loss ◽

Short Cycle ◽

Luteal Function ◽

Expression Of Genes ◽

Molecular Events ◽

Cast Doubt ◽

Ram Effect

Anoestrous ewes can be induced to ovulate by the socio-sexual, ‘ram effect’. However, in some ewes, the induced ovulation is followed by an abnormally short luteal phase causing a so-called ‘short cycle’. The defect responsible for this luteal dysfunction has not been identified. In this study, we investigated ovarian and uterine factors implicated in male-induced short cycles in anoestrous ewes using a combined endocrine and molecular strategy. Before ovulation, we were able to detect a moderate loss of thecal expression of steroid acute regulatory protein (STAR) in ewes that had not received progesterone priming (which prevents short cycles). At and following ovulation, we were able to identify a significant loss of expression of genes coding key proteins involved in the biosynthesis of progesterone (STAR,CYP11A1andHSD3B1(HSD3B)) as well as genes coding proteins critical for vascular development during early luteal development (VEGFAandKDR(VEGFR2)), suggesting dysfunction in at least two pathways critical for normal luteal function. Furthermore, these changes were associated with a significant reduction of progesterone production and luteal weight. Additionally, we cast doubt on the proposed uterus-mediated effect of prostaglandin F2α (PGF2α) as a cause of short cycles by demonstrating the dysregulation of luteal expression of the PGF receptor, which mediates the luteal effects of PGF2α, and by finding no significant changes in the circulating concentrations of PGFM, the principal metabolite of PGF2α in ewes with short cycles. This study is the first of its kind to examine concurrently the endocrine and molecular events in the follicular and early luteal stages of the short cycle.Free French abstractA French translation of this abstract is freely available athttp://www.reproduction-online.org/content/147/3/357/suppl/DC1

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