Endocrine Abstracts

Parturition in the ewe is initiated by the fetus following the cortisol rise via activation of the hypothalamic-pituitary-adrenal axis and increased intrauterine PG production. Dietary n-6 PUFAs, noteceably linoleic acid (LA) are the precursors for PG synthesis. The maternal intercotyledonary endometrium is the main site of PGF2alpha during labour. This study investigated the effect of dietary n-6 PUFA supplementation on uterine PG production at term. Ewes (n=32) we...

Polyunsaturated fatty acids (PUFAs) supply precursors for prostaglandin (PG) synthesis and PGs in turn influence many aspects of reproduction. We have previously demonstrated that supplementation of the diet of dairy cows with the n-6 PUFA [linoleic acid (LA)] significantly inhibited uterine PG production. In this study we have investigated the effects of various n-6 PUFAs in vitro on PG production by ovine endometrial cells.Endometrial tissue was...

Polyunsaturated fatty acids (PUFA) act as precursors for prostaglandin (PG) synthesis. PGs both inhibit and stimulate ovarian steroidogenesis. We have therefore examined the hypothesis that high n-3 PUFA diets affect ovarian steroid synthesis through modulating prostaglandin synthesis.Welsh mountain ewes were individually fed a control diet or a diet containing linseed (high in n-3 PUFA) for 6 weeks. To assess the impact of the diet during differe...

Increased dietary intake of polyunsaturated fatty acids (PUFAs) has been reported to be associated with a decreased incidence of cardiovascular disease. Increased dietary intake of polyunsaturated fatty acids (PUFAs) has been reported to be associated with a decreased incidence of cardiovascular disease. We have recently reported that ovarian steroid synthesis in ewes fed a diet high in n-3 PUFAs is significantly compromised1. Hence in this study we have assessed th...

Cervical dilatation and myometrial contractions are essential processes of both pre-term and term labour. These processes are associated with enhanced production of 2-series prostaglandins (PGs) from polyunsaturated fatty acids (PUFAs), by feto-placental tissues. Some human epidemiological studies suggest that specific PUFAs can alter the length of gestation. The amnion is a prime site for PG synthesis in the feto-placental unit. Thus perturbations of PG synthesis in this tiss...

Recent health reports state that the population of western countries is consuming excessive amounts of n-6 polyunsaturated fatty acids (PUFAs) in the diet. Dietary n-6 PUFAs are precursors for prostaglandin (PG) synthesis, which play important roles in parturition. Increased dietary n-6 PUFA could thus alter PG production. This study determined the effect of a high n-6 PUFA diet on PG production and the timing of the onset of labour. Pregnant Welsh Mountain ewes were fed an is...

Public health policy in recent years has favoured a reduction in saturated fats in favour of polyunsaturated fats due to the numerous health benefits of polyunsaturated fatty acids (PUFAs). Previous studies have demonstrated that PUFAs modulate gonadal steroidogenesis. We have therefore investigated the hypothesis that PUFAs modify steroidogenesis through affecting components of the cholesterol metabolising machinery, including steroidogenic acute regulatory (StAR) protein and...