Effect of Certain Toxicants on Gonadotropin-Induced Ovarian Non-Esterified Cholesterol Depletion and Steroidogenic Enzyme Stimulation of the Common Carp Cyprinus carpio in vitro

Isolated ovarian tissues from the common carp, Cyprinus carpio were incubated in vitro to obtain a discrete effect of four common toxicants of industrial origin, namely phenol, sulfide, mercuric chloride and cadmium chloride, on gonadotropin-induced alteration of nonesterified and esterified cholesterol and steroidogenic enzymes, △5-3β-HSD and 17β-HSD activity. Stage II ovarian tissue containing 30-40% mature oocytes were shown to be most responsive to gonadotropins in depleting only nonesterified cholesterol moiety and stimulating the activity of both. Safe doses of above mentioned toxicants when added separately to stage II ovarian tissue with oLH (1 μg/incubation) gonadotropin-induced depletion of nonesterified cholesterol and gonadotropin-induced stimulation of the activity of both enzymes was significantly inhibited. Esterified cholesterol remained almost unaltered. Findings clearly indicate the impairment of gonadotropin induced fish ovarian steroidogenesis by the four toxicants separately.

The interplay between non-esterified fatty acids and bovine peroxisome proliferator-activated receptors: results of an in vitro hybrid approach

Background: In dairy cows circulating non-esterified fatty acids(NEFA) increase early post-partum while liver and other tissues undergo adaptation to greater lipid metabolism, mainly regulated by peroxisome proliferator-activated receptors(PPAR). PPAR are activated by fatty acids(FA), but it remains to be demonstrated that circulating NEFA or dietary FA activate bovine PPAR. We hypothesized that circulating NEFA and dietary FA activate PPAR in dairy cows.Methods: The dose-response activation of PPAR by NEFA or dietary FA was assessed using HP300 e digital dispenser and luciferase reporter in several bovine cell types. Cells were treated with blood plasma isolated from Jersey cows before and after parturition, NEFA isolated from the blood plasma, FA released from lipoproteins using milk lipoprotein lipase(LPL), and palmitic acid(C16:0). Effect on each PPAR isotype was assessed using specific synthetic inhibitors.Results: NEFA isolated from blood serum activate PPAR linearly up to ~ 4-fold at 400 μmol/L in MAC-T cells but had cytotoxic effect. Addition of albumin to the culture media decreases cytotoxic effects of NEFA but also PPAR activation by ~ 2-fold. Treating cells with serum from peripartum cows reveals that much of the PPAR activation can be explained by the amount of NEFA in the serum(R~2 = 0.91) and that the response to serum NEFA follows a quadratic tendency, with peak activation around 1.4 mmol/L. Analysis of PPAR activation by serum in MAC-T, BFH-12 and BPAEC cells revealed that most of the activation is explained by the activity of PPARδ and PPARγ, but not PPARα. Palmitic acid activated PPAR when added in culture media or blood serum but the activation was limited to PPARδ and PPARα and the response was nil in serum from post-partum cows. The addition of LPL to the serum increased > 1.5-fold PPAR activation.Conclusion: Our results support dose-dependent activation of PPAR by circulating NEFA in bovine, specifically δand γ isotypes. Data also support the possibility of increasing PPAR activation by dietary FA;however, this nutrigenomics approach maybe only effective in pre-partum but not post-partum cows.

Type 2 diabetes with good glycemic control have improved insulin response and lower non-esterified fatty acid level after a meal challenge

Background: Pathogenesis of type 2 diabetes (T2DM) involves defects in β-cell function with impaired first and second phase insulin response, and reduced insulin sensitivity. Diabetic dyslipidemia is an important and common risk factor for coronary heart disease (CHD). Aims: This study examined the effect of glycemic control on post prandial insulin and lipid parameters in response to a standardised meal challenge among Type 2 diabetes patients with good and poor glycemic control. Methods: We cross-sectionally studied 31 T2DM patients with good glycemic control and 32 T2DM patients with poor glycemic control. Subjects were given, after minimum 10 hours of fasting, a standard meal containing 58% fat. Fasting and serial postprandial blood samples were taken over 8 hours to determine levels of triglyceride, direct LDL-C, apoB lipoprotein, non-esterified-fatty-acid, insulin and blood glucose. Results: Post prandial NEFA was significantly higher in poor controlled diabetes patients compared to good control diabetes patients (p = 0.019), and post-hoc analysis showed significant difference from 3 hours post prandial to 4 hours post prandial, where p= 0.021. Although the difference in insulin between the 2 groups did not reach statistical significance (p =0.058), post-hoc analysis showed significant difference between the 2 groups from fasting to 1 hour post prandial (p = 0.034) despite postprandial glucose being significantly higher in poor controlled diabetes patients (p < 0.001), throughout the postprandial period. Conclusion: T2DM patients with good glycemic control have improved insulin response with lower non-esterified fatty acid.

The Effects of Exercise on Serum Chemistry, Non-Esterified Fatty Acid, Insulin and Glucagon Dynamics during a 400 Meter Sprint in Racing Greyhounds

The effects of Greyhound racing on plasma insulin, glucagon and non-esterified fatty acid have not been extensively studied. We sought to examine the effects of exercise in 19 greyhounds trialed over 400 meters on serum biochemistry, osmolality, nonessential fatty acids, and the major glucoregulatory hormones insulin and glucagon, before and after racing. Due to the non-traditional dietary patterns of many racing Greyhounds, the diet was analyzed for macro and micro-nutrient assessment to determine adequacy of the diet. Many significant biochemical changes were observed and agreed with previous studies, except for low resting glucose, low post-exercise globulin and phosphorus concentrations, and a high CK both before and after exercise. Insulin concentrations increased 10 minutes post-exercise which might be a result of the rise in serum glucose observed. Non-esterified fatty acids decreased 10 minutes post-exercise, as a likely result of the insulin facilitated cellular uptake of fatty acids early in recovery. Glucagon concentrations did not change after exercise despite the rise in insulin. The diet analysis found some mineral deficiencies in sodium, selenium, iodine and copper;and contained a far higher protein and fat content, being atypical of diets that have been shown to improve the performance in racing Greyhounds.

Effect of flaxseed supplementation on metabolic state,endocrine profiles,body composition and reproductive performance of sows

Objective:To assess the effect of flaxseed supplementation on metabolic profile,endocrine concentrations,non-esterified fatty acids(NEFA),body composition variables,and reproductive performance of sows.Methods:All the 21 crossbred Large White Yorkshire sows were considered in the study period starting at day 1 of current farrowing when the feeding of specific supplemental ration was started until the day of subsequent farrowing(days 150-155)and were equally allocated into three groups.Group 1 served as the control group and followed their normal feeding schedule.Group 2 and group 3,in addition to their normal feeding schedule,were supplemented with flaxseed at a rate of 0.5%and 1.0%of the dry matter,respectively.Blood samples were collected 15 days prior to farrowing,on the day of farrowing(day 0),at weekly intervals until day 28 of lactation and at monthly intervals during gestation to harvest the plasma.Plasma was used to assess the metabolic and endocrine status of sows.Body weight of each sow and individual birth weight of all piglets born were measured.Results:Flaxseed supplementation led to decrease in plasma cholesterol and triglyceride levels in the supplemented groups than in the control group(P<0.05).Plasma estradiol-17βlevel was higher in group 2 than that in group 1 and 3 on day 90 of the gestation period(P<0.05).The mean plasma level of insulin-like growth factor 1 was higher in group 3 than that in group 1 and 2 both in late lactation(day 28)as well as in early gestation(day 30)(P<0.05).Plasma NEFA and weight gain were greater in sows of group 2 and 3 compared to those fed with the normal control diets(P<0.05).The proportion of pregnant sows relative to sows bred was 100.0%in group 2 and 3 and 85.7%in the control group.Piglet mortality was lower in group 2 and 3 compared to group 1(P>0.05).Conclusions:Flaxseed improves endocrine profiles,NEFA concentrations and body weight,resulting in better pregnancy rate and litter size.

Can Dietary Pomegranate Peels Reduce Stress Responses Associated with Group Mixing of Holstein Beef Calves？

The study investigated whether dietary CPE （concentrated pomegranate peel extract） may mitigate the negative effects associated with group mixing prior to marketing and enhance beef meat quality. Twenty-two bull calves were reared in triplets and divided to control （n = 9） and CPE-treated （n = 13） groups. CPE was supplemented during eight months of rearing, and calves were mixed 34 d prior to marketing to control and treatment groups. Calves were monitored for weight gain, rumination, activity, metabolic and oxidative stress responses, Finally, meat quality traits were examined. The results find that pre-mixing activity （P 〈 0.0001）, non-esterifies fatty acids （P = 0.02） and plasma testosterone （P = 0.005） levels were higher in the treatment group. Following mixing, activity （P 〈 0.0001 ） and plasma anti-oxidative capacity （P = 0.05） increased in the treatment compared to the control group. In spite of the above, dietary supplementation of CPE didn＇t reveal improvement of meat quality parameters by means of meat pH and shelf life It indicated that improved serum anti-oxidant capacity in the CPE calves was not sufficient to prevent the mixing effects on meat quality. A combined CPE concentration and mixing management should be examined in order to reduce mixing related effects on meat quality.