Ovarian activity and oocyte development during follicular development in pigs at different reproductive phases estimated by the repeated endoscopic method

The aim of the present study was to assess follicular and oocyte development in the same gilts during three phases of their reproductive life [prepuberal gilts (PP; 6.0 months of age), puberal gilts (P; 9.5 months of age) and primiparous sows (S)]. Follicular development was stimulated by the injection of 1,000 IU of equine chorionic gonadotropin (eCG) followed by 500 IU of human chorionic gonadotropin (hCG) 72 h later. Cumulus-oocyte-complexes (COCs) were recovered by endoscopic ovum pick up/aspiration from preovulatory follicles of the left ovary, and the follicular fluid (FF) from the right ovary was collected 34 h after the hCG treatment by endoscopy. Altogether, 19 pigs were used in the PP and P trials and 12 in the S trial. From the left ovaries, 168, 190 and 82 follicles were aspirated and 106, 125 and 42 COCs, respectively, were recovered (recovery rate 61 +/- 27, 63 +/- 21 and 53 +/- 22%, respectively). The mean number of follicles was greater in the P phase than in the PP phase (19.7 +/- 6.8 vs. 15.7 +/- 6.8; p=0.06) and S phases (14.2 +/- 4.0; p<0.05). More uniform oocytes with an expanded cumulus were aspirated in the P and PP phases than in the S phase (90 and 78 vs. 46%; p<0.05). Furthermore, the meiotic configuration in oocytes (T I/M II stage) differed between the three phases (56 and 62 vs. 0%; p<0.05). Progesterone (P4) levels in FF decreased from 590.0 +/- 333.6 (PP) to 249.1 +/- 72.6 (P) and 161.4 +/- 75.2 ng/ml (S) (p<0.05). Estradiol-17beta (E2) levels differed between PP and P gilts and S sows (9.3 +/- 2.9, 21.9 +/- 10.6 and 94.0 +/- 15.9 pg/ml, respectively; p<0.05), and the P4/E2 ratio was 72, 15 and 5, respectively. These results indicate differences in follicular and oocyte development between the reproductive phases investigated. Puberal gilts should preferably be used in IVF and breeding programs. The lower reproductive potential of primiparous sows must be taken into consideration in breeding. Any prediction of lifetime performance based on individual ovarian reactions of prepuberal gilts is unreliable.     

Comparison of luteinizing hormone and steroid hormone secretion during the peri- and post-ovulatory periods in Mangalica and Landrace gilts

The objective of this study was to determine plasma concentrations of luteinizing hormone (LH), progesterone (P4) and estradiol-17beta (E2) in Mangalica gilts (M), a Hungarian native breed, and compare them with Landrace gilts (L) during the peri- and post-ovulatory periods. The estrous cycle of gilts was synchronised by Regumate feeding, and ovulation was induced with a gonadotropin-releasing hormone (GnRH) agonist. Blood sampling was carried out via indwelling jugular catheters three times a day and in 2-h intervals during a 16-h period after the GnRH application. The concentrations of LH, E2 and P4 were determined by immunoassays. Gilts of both breeds showed a typical gonadotropin and gonadal hormone secretion pattern. Preovulatory E2 peaks were observed on day 2 (M) and day 4 (L) after the last Regumate feeding. Highest E2 concentration was different between M and L breeds (46.5 +/- 5.7 vs. 26.0 +/- 6.8 pg/ml, P < 0.05). Maximum LH levels measured up to 6 h after GnRH were not different between M and L breeds (11.5 +/- 4.1 vs. 6.6 +/- 2.3 ng/ml). Both LH amounts during surge (41.1 +/- 15.9 vs. 27.5 +/- 6.1 ng/ml) and total over LH release (73.4 +/- 22.2 vs. 50.0 +/- 8.7 ng/ml) did not differ significantly between M and L breeds. P4 concentrations started to rise on day 6 after Regumate feeding and increased significantly from 0.6 +/- 0.3 and 0.7 +/- 0.4 ng/ml to maximal 14.0 +/- 2.4 and 11.3 +/- 2.1 ng/ml in M and L breeds, respectively. Mean P4 secretion was higher in M on days 10-15 (12.9 +/- 2.6 vs. 9.3 +/- 2.2 ng/ml; P<0.05). At the same time the number of corpora lutea was lower in M compared to L (10.3 +/-1.5 vs. 17.8 +/- 5.0, P<0.05). In our experiment, there was no evidence that differences in the secretion of analysed hormones during the peri- and post-ovulatory periods are a possible cause of usually lower fecundity in Mangalica gilts.     

Effect of dietary protein quality and essential fatty acids on fatty acid composition in the liver and adipose tissue after rapid weight loss in overweight cats

OBJECTIVE: To examine effects of dietary protein quality (casein [CA] vs corn gluten [CG]) and dietary lipids (corn oil [CO] vs oil blend [OB] rich in long-chain polyunsaturated fatty acids [LCPUFAs]) on fatty acid composition in liver and adipose tissue after weight loss in overweight cats. ANIMALS: 24 ovariohysterectomized adult cats. PROCEDURE: Cats were allowed ad libitum access to a high-quality diet until they weighed 30% more than their ideal body weight. Cats were then randomly assigned to 1 of 4 weight-reduction diets (6 cats/diet) and were fed 25% of maintenance energy requirements per day. Diets consisted of CG-CO, CA-CO, CG-OB, and CA-OB, respectively, and were fed until cats lost weight and returned to their original lean body mass. Liver biopsy specimens and samples of perirenal, subcutaneous, and abdominal fat were obtained and analyzed for fatty acid content. RESULTS: Following weight loss, fatty acid composition of the liver and adipose tissue was primarily affected by protein quality in that cats fed CA had significantly higher percentages of 20:4(n-6) and 22:6(n-3) fatty acids than those fed CG. Cats fed the CG-CO diet had the lowest concentrations of LCPUFAs, suggesting that dietary lipids and protein quality each influence fatty acid composition in tissues. CONCLUSIONS AND CLINICAL RELEVANCE: These data provide direct evidence that dietary protein quality alters fatty acid composition of tissues during weight loss in cats. The fatty acid patterns observed suggest that protein quality may alter fatty acid composition through modulation of desaturase activity.     

Influence of dietary protein and lipid on weight loss in obese ovariohysterectomized cats

OBJECTIVE: To determine effects of dietary lipid and protein on development of hepatic lipidosis (HL) and on physical and biochemical indices following rapid weight loss in cats. ANIMALS: 24 ovariohysterectomized cats. PROCEDURE: Cats were fed a high energy diet until they gained 30% of their ideal body weight and then randomly assigned to receive 1 of 4 weight-reduction diets (6 cats/diet) at 25% of maintenance energy requirements per day. Diets contained a low or high quality protein source and a lipid source deficient or sufficient in long chain essential fatty acids (LCEFA). Serum and plasma samples and liver biopsy specimens were obtained for biochemical analyses and determination of hepatic lipid content before and after weight gain and during and after weight loss. RESULTS: Irrespective of weight-reduction diet fed, all cats lost weight at a comparable rate (4.51 to 5.00 g/d/kg of obese body weight). Three cats developed hepatic lipidosis. Significant changes in plasma insulin, cholesterol, triglyceride, and serum glucose concentrations were detected after weight gain and weight loss in all diet groups, but values for these variables did not differ among groups. CONCLUSIONS AND CLINICAL RELEVANCE: Cats can lose 25 to 30% of their obese body weight over 7 to 9 weeks without developing overt clinical signs of HL, provided that weight-reduction diets are highly palatable, contain a high quality protein, have a source of LCEFA, and are fortified with vitamins and microminerals. However, rapid weight loss may increase risk factors associated with development of diabetes mellitus.     

Effect of dietary protein quality and fatty acid composition on plasma lipoprotein concentrations and hepatic triglyceride fatty acid synthesis in obese cats undergoing rapid weight loss

OBJECTIVE: To determine effects of dietary lipid and protein on plasma lipoprotein and free fatty acid concentrations and hepatic fatty acid synthesis during weight gain and rapid weight loss in cats. ANIMALS: 24 ovariohysterectomized cats. PROCEDURE: Cats were fed a high energy diet until they gained 30% of their ideal body weight and then randomly assigned to receive 1 of 4 weight reduction diets (6 cats/diet) at 25% of maintenance energy requirements. Diets contained a low or high quality protein source and a lipid source deficient or sufficient in long chain essential fatty acids. Plasma samples and liver biopsy specimens were obtained before and after weight gain and during and after weight loss for determination of free fatty acid, triglyceride, and lipoprotein concentrations. Synthesis of these substances was measured by use of isotope enrichment. RESULTS: Plasma total cholesterol concentration and concentration of lipoprotein fractions increased after weight gain, compared with baseline values. Weight loss resulted in a significant decrease in concentrations of all lipoprotein fractions except high density lipoprotein. High density lipoprotein concentration was significantly greater in cats fed diets containing an oil blend, compared with cats fed diets containing corn oil. Fatty acid synthesis after weight loss was below the detection limit of the measurement technique. CONCLUSIONS AND CLINICAL RELEVANCE: In cats undergoing rapid weight loss there is neither increased triglyceride synthesis nor decreased transport of very low density lipoproteins from the liver, suggesting that their involvement in the development of hepatic lipidosis may be minimal.     

Structural mechanism for statin inhibition of HMG-CoA reductase

HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase (HMGR) catalyzes the committed step in cholesterol biosynthesis. Statins are HMGR inhibitors with inhibition constant values in the nanomolar range that effectively lower serum cholesterol levels and are widely prescribed in the treatment of hypercholesterolemia. We have determined structures of the catalytic portion of human HMGR complexed with six different statins. The statins occupy a portion of the binding site of HMG-CoA, thus blocking access of this substrate to the active site. Near the carboxyl terminus of HMGR, several catalytically relevant residues are disordered in the enzyme-statin complexes. If these residues were not flexible, they would sterically hinder statin binding.     

Light hydrocarbon production in freshwater marsh soil as influenced by soil redox conditions

Water, Air, & Soil Pollution - The potential role of wetland soil redox condition to global atmospheric light hydrocarbon budget was evaluated. The effect of soil redox condition on gaseous...     

Overview of investigations into mercury in ground water, soils, and septage, new jersey coastal plain

Since the early 1980s, investigations by health departments of eight counties in southern New Jersey, by the NJ Department of Environmental Protection (NJDEP), and subsequently by the US Geological Survey (USGS), have shown that Hg concentrations in water tapped by about 600 domestic wells exceed the maximum contaminant level (MCL) of 2 μg/L. The wells are finished in the areally extensive unconfined Kirkwood-Cohansey aquifer system of New Jersey's Coastal Plain; background concentrations of Hg in water from this system are < 0.01 μg/L. Evidence of contributions from point sources of Hg, such as landfills or commercial and industrial hazardous-waste sites, is lacking. During 1996–2003, the USGS collected water samples from 203 domestic, irrigation, observation, and production wells using ultraclean techniques; septage, leach-field effluent, soils, and aquifer sediments also were sampled. Elevated concentrations of NH₄, B, Cl, NO₃, and Na and presence of surfactants in domestic-well water indicate that septic-system effluent can affect water quality in unsewered residential areas, but neither septage nor effluent appears to be a major Hg source. Detections of hydrogen sulfide in ground water at a residential area indicate localized reducing conditions; undetectable SO₄ concentrations in water from other residential areas indicate that reducing conditions, which could be conducive to Hg methylation, may be common locally. Volatile organic compounds (VOCs), mostly chlorinated solvents, also are found in ground water at the affected areas, but statistically significant associations between presence of Hg and VOCs were absent for most areas evaluated. Hg concentrations are lower in some filtered water samples than in paired unfiltered samples, likely indicating that some Hg is associated with particles or colloids. The source of colloids may be soils, which, when undisturbed, contain higher concentrations of Hg than do disturbed soils and aquifer sediments. Soil disturbance during residential development and inputs from septic systems are hypothesized to mobilize Hg from soils to ground water.