The effect of LPS on LH release and gene expression of LH-β, GnRH-R and TLR4 in the anterior pituitary of follicular phase ewes – an in vitro study
Journal Title: Journal of Animal and Feed Sciences - Year 2013, Vol 22, Issue 2
Abstract
The study was designed to determine the in vitro effect of bacterial endotoxin – lipopolysaccharide (LPS) – on luteinizing hormone (LH) secretion from anterior pituitary (AP) explants collected from saline-treated ‘healthy’ and LPS-treated ewes in the follicular phase. In the AP explants, the expression of LH-β, gonadotropin-releasing hormone receptor (GnRH-R) and Toll-like receptor 4 (TLR4) genes was also assayed. It was found that explants incubated alone with LPS, as well as together with LPS-binding protein (LBP), abolished the stimulatory effect of GnRH on LH release. LPS added without LBP did not suppress LH-β gene expression in ‘healthy’ APs, however. Moreover, LBP intensified the inhibitory effect of LPS on gene expression in ‘healthy’ APs. These results show that LPS is a potent negative modulator of LH secretion and suggest that its direct action on the pituitary gland could be one of the mechanisms via which an immune/inflammatory challenge inhibits the reproductive process.
Authors and Affiliations
K. Haziak, A. P. Herman, D. Tomaszewska-Zaremba
Evaluation of dry matter intake, average daily gain and faecal nitrogen excretion predicted by the Cornell Net Carbohydrate and Protein System with different beef cattle breeds fed in China
This study was conducted to evaluate the predictions of dry matter intake (DMI), average daily gain (ADG), and faecal nitrogen (N) excretion by the Cornell Net Carbohydrate and Protein System Version 6.1.26 (CNCPSv6) in...
Evaluation of microalgae as sources of digestible nutrients for monogastric animals
The study was carried out to evaluate three microalgae as potential nutrient sources in diets for monogastric animals. In a digestibility experiment with adult mink (Mustela vison), the microalgae Nannochloropsis oceanic...
Bayesian segregation analysis of test-day milk yield in Tunisian Sicilo-Sarde dairy sheep
Segregation analyses were performed using a Monte Carlo Markov Chain (MCMC) method implemented using Gibbs Sampling. A total of 8387 test-day milk records obtained from the Sicilo-Sarde dairy flock of the Tunisian Nation...
Two different forms and levels of CuSO4 in piglet feeding: liver, plasma and faeces copper status
A 35-d experiment involving 150 crossbred pigs weaned at 26 ± 2 d of age was conducted to evaluate the effect of different forms of CuSO4 on the copper content of liver, plasma and faeces. Piglets were randomly allocated...
Evaluation of purine metabolites - creatinine index to predict the rumen microbial protein synthesis from urinary spot samples in Barbari goats
an alternative to performing a total urine collection to predict the microbial nitrogen (MN) supply in goats. The study was conducted in two phases. Phase I was comprised of fasting metabolism trial of eight goat bucks (...