Plasma paraoxonase, health, inflammatory conditions, and liver function in transition dairy cows.

Paraoxonase (PON) is a liver protein with hydrolase activity that is released into the blood stream. Paraoxonase may serve as an index of liver function because it is drastically reduced in chronic liver damage. Sixty-seven periparturient dairy cows were used to evaluate the relationship between plasma PON, health problems, inflammatory conditions, and liver function. Baseline plasma PON concentrations during the first 30 d in milk (DIM) were retrospectively used to group cows into quartiles. Metabolic profile, lipid metabolites (e.g., nonesterified fatty acids, beta-hydroxybutyrate), inflammatory indices (haptoglobin, ceruloplasmin), low and high density lipoprotein cholesterol, vitamin A, vitamin E, reactive oxygen metabolites, total antioxidants, and PON in plasma were measured 2 wk before to 8 wk after calving. Weekly milk yield, body condition score, and all health problems were recorded. After parturition (7 DIM), cows in the lower PON group had the lowest plasma concentrations of negative acute phase proteins compared with the higher PON group for retinol binding protein (23.2 +/- 2.86 vs. 36.0 +/- 2.96 microg/dL of vitamin A), albumin (31.6 +/- 0.73 vs. 33.9 +/- 0.75 g/L), total cholesterol (2.04 +/- 0.30 vs. 2.45 +/- 0.42 mmol/L), and the highest concentrations of haptoglobin (0.67 vs. 0.24 +/- 0.03 g/L; positive acute phase protein) and globulins (37.2 vs. 32.3 +/- 1.4 g/L). Plasma bilirubin was highest in the cows (10.1 vs. 6.2 +/- 0.6 micromol/L) in the lowest PON quartile. Plasma PON was negatively correlated with haptoglobin (r = -0.39) and bilirubin (r = -0.42) and positively correlated with retinol binding protein (r = 0.54), albumin (r = 0.38), and cholesterol (r = 0.55) fractions. A total of 82.3% of cows in the lower quartile and no cows in the upper quartile experienced serious inflammation. Lower quartile cows produced 28.1 +/- 10.3 kg of milk/d; whereas upper quartile cows produced 38.3 +/- 7.7 kg of milk/d during the first 30 DIM. A reduction in the ability of the liver to cope with the increased metabolic demand near parturition in dairy cows can be diagnosed using changes in baseline plasma PON

Circulating amino acids in blood plasma during the peripartal period in dairy cows with different liver functionality index

The liver functionality index (LFI) measures the changes of albumin, cholesterol, and bilirubin concentrations between 3 and 28 d postpartum. This composite index, based on variables with direct relevance to liver-specific plasma protein synthesis (albumin), hepatic/intestinal lipoprotein synthesis (cholesterol), and clearance of breakdown products of heme catabolism (bilirubin), provides a tool for evaluating manifestations of hepatic disease. Both energy and protein metabolism are likely to be affected by various physiological challenges in this period but have not been tested systematically. The present study was conducted to profile AA in cows with high or low LFI during the peripartal period and relate this to production outcomes. Eighteen multiparous cows were used from −21 through 28 d around parturition and divided retrospectively into the high or low LFI group. Blood samples were obtained on −21, −14, −7, 1, 3, 7, 10, 14, 17, 21, and 28 d relative to calving, and biomarkers and AA in plasma were measured. Grouping based on LFI resulted in 8 cows with high LFI (HLFI) and 10 cows with low LFI (LLFI). Although the temporal response in dry matter intake (DMI, 16.3 kg/d) and body condition score (2.56) did not differ, cows with high compared with low LFI had greater overall milk production (37.9 vs. 32.9 kg/d) although energy-corrected milk yield did not differ (42.6 vs. 38.7 kg/d). As expected, cows grouped as LLFI had lower cholesterol and albumin but greater bilirubin after calving compared with HLFI animals. Despite similar temporal responses in DMI between groups, concentrations of total AA were greater in HLFI, particularly after calving. Although concentrations of total essential AA (EAA) and branched-chain AA did not differ with LFI status, cows in HLFI had greater concentrations of Thr and Ile postpartum. Nearly all plasma AA concentrations followed the general trend of a nadir at 1 d after calving followed by a gradual increase to prepartal levels before 28 d. Glycine was the only AA exhibiting a gradual increase in concentration through the transition, with a maximum at 7 d postpartum followed by a gradual decrease. We detected no effect of LFI status on plasma Lys, which decreased markedly from −21 d to calving, followed by an increase to prepartal values by d 7. In contrast, concentrations of Met and His decreased markedly between −21 and 10 d and did not reach prepartal values by 28 d. The marked decrease in Gln concentration after calving regardless of LFI might compromise immune function during this period. Overall, the results indicate the existence of an association among inflammation, liver function postpartum, and AA plasma concentrations, irrespective of temporal differences in DMI. Cows with better indices of liver function produced more milk and maintained greater concentrations of total AA and some EAA such as Thr and Ile. Whether these AA played a direct role in the greater milk production remains to be determined

Gene expression profiles in human HepG2 cells treated with extracts of the Tamarindus indica fruit pulp

Tamarindus indicaL. (T. indica) or locally known as asam jawa belongs to the family of Leguminosae. The fruit pulp had been reported to have antioxidant activities and possess hypolipidaemic effects. In this study, we attempted to investigate the gene expression patterns in human hepatoma HepG2 cell line in response to treatment with low concentration of the fruit pulp extracts. Microarray analysis using Affymetrix Human Genome 1.0 S.T arrays was used in the study. Microarray data were validated using semi-quantitative RT–PCR and real-time RT–PCR. Amongst the significantly up-regulated genes were those that code for the metallothioneins (MT1M, MT1F, MT1X) and glutathione S-transferases (GSTA1, GSTA2, GST02) that are involved in stress response. APOA4, APOA5, ABCG5 and MTTP genes were also significantly regulated that could be linked to hypolipidaemic activities of the T. indica fruit pulp

Treatments with antibiotics or with Anti-Endotoxin serum before calving: effects on milk yield and fertility

An inflammatory like condition is known to be frequent around calving (Cappa et al., 1989) and could be promoted by the release of cytokines (i.e. IL-1, TNFα etc.) by immune cells following to various stimuli (i.e. trauma, infection, virus, endotoxin, digestive and metabolic disorders etc.). Cytokines have local and systemic effects and namely increase body temperature and decrease feed intake (Elsasser et al., 1997). The anorexic and other effects of cytokines could cause serious consequences around calving, i.e. on liver lipid metabolism and reproduction......

Documento per la ripresa della vita scolastica

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