Reproduction Abstracts

In photoperiodic species, the pattern of pineal melatonin secretion translates the effects of day length on the annual reproductive cycle. Continuous delivery of exogenous melatonin to sheep during the non-breeding season is known to activate the gonadotrophic axis, and to suppress prolactin secretion through a mechanism involving the pars tuberalis (PT) of the pituitary gland. Recent studies have revealed that vascular endothelial growth factor (VEGF), a major regulator of an...

Recent studies have shown that microvasculature remodelling of the ovine pituitary gland is seasonally regulated through mechanisms involving the differential expression of pro-angiogenic (VEGF165) and anti-angiogenic (VEGF165b) isoforms of vascular endothelial growth factor (VEGF). As for other photoperiodic species, the pattern of pineal melatonin secretion mediates the effects of day length on the sheep seasonal reproductive cycle. In this study, we in...