Reproduction performance and blood biochemical parameters in dairy cows: Relationship with oxidative stress status

Background and Aim: During the last decades, reproduction performances declined dramatically worldwide, but little is known concerning the involvement of oxidative stress as a causative factor. Oxidative stress may act at different levels, with negative impacts on cell membrane integrity and other active molecules with potential subsequent effects on reproduction. The aim of the current study was to investigate the oxidative stress status in cows according to their reproductive performances. Materials and Methods: Peripheral blood concentration of two oxidative stress biomarkers, glutathione S-transferase (GST) and malondialdehyde (MDA), and other biochemical parameters (glucose, total lipids, cholesterol, triglycerides, albumin, total proteins, calcium, urea, creatinine, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase) were determined in 40 healthy cows. Body condition score (BCS), calving to first service interval (FSI), calving to conception interval (CCI), and the number of service per conception (SPC) were simultaneously recorded for each cow. Results: Concerning FSI, three groups were established: Group 1 (from 44 to 60 days), Group 2 (from 60 to 70 days), and Group 3 (from 70 to 80 days). For CCI, two groups were considered: Group 1 (110 days). MDA showed significant high values only in cows with the lowest BCS (1.5) compared to cows with BCS note of 2.5 and 3.5. No significant difference was observed in cows oxidative stress status (MDA and GST) according to reproductive performances (FSI, CCI, and SPC) in all studied groups. Conclusion: The results revealed relatively altered oxidative stress status in cows with abnormal reproductive performances; however, no significant difference was recorded whatever the considered reproductive parameter

Circulating microparticles released during dyslipidemia may exert deleterious effects on blood vessels and endothelial function

International audienceAims: To compare the bioactivity of circulating microparticles (MPs) isolated from dyslipidemic Psammomys obesus (P. obesus) fed a high-energy diet (HED) with those released from healthy P. obesus fed a normal diet (ND). Methods: Vascular reactivity of aortic rings was evaluated by myography, after 24 h incubation in the absence or in the presence of circulating MPs isolated, by differential centrifugations, from the plasma of animals subjected to HED (MPs HED) or ND (MPs ND) for 12 weeks. Human umbilical vein endothelial cells (HUVECs) were treated for 24 h with MPs HED or MPs ND animals and subjected to immunofluorescence staining of caveolin-1 (cav-1), intercellular adhesion molecule-1 (ICAM-1), endothelial nitric oxide synthase (eNOS), F-actin and reactive oxygen species (ROS) detection. Results: The HED exerted a distinctly pronounced hyperlipidemic effect marked by plasmatic increase of total cholesterol, low-density lipoprotein-cholesterol (LDL-C) and triglyceride (TG). Both MPs ND and MPs HED induced a significant reduction of maximal relaxation induced by acetylcholine (ACh). Interestingly, MPs HED significantly decreased eNOS expression up to~25% and increased ROS production up to~75% on in vitro treated HUVECs. Moreover, in HUVECs, MPs HED significantly decreased cav-1 expression up to~50% whereas significant increase of ICAM-1 expression by about 2-fold approximately was observed. Conclusion: Our experimental study demonstrated the dual role of MPs on vascular function by modulating endothelial cell function. Furthermore, MPs may be considered as vectors of a bioactive information contributing to inflammation and vascular damage