Genetic and phenotypic relationships between individual subcutaneous backfat layers and percentage of longissimus intramuscular fat in Duroc swine.
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Progeny (n = 589) of randomly mated Duroc pigs were used to determine the genetic and phenotypic relationships between individual s.c. backfat layers and i.m. fat percent (IMF) of the longissimus. Five days before slaughter, cross-sectional ultrasound images were collected at the 10th rib by a National Swine Improvement Federation-certified ultrasound technician using an ultrasound machine (Aloka 500 SSD) fitted with a 12-cm linear array transducer. Off-midline backfat (SBF) and loin muscle area (SLMA) were measured. Individual s.c. backfat layers were measured at the same location: outer (OBF), middle (MBF), and inner (IBF). Off-midline backfat (CBF) and loin muscle area (CLMA) were measured on the carcass 24 h postmortem. A slice from the 10th rib of the loin muscle was obtained for determination of IMF. Heritability estimates and genetic correlations were calculated fitting all possible two-trait animal models in MATVEC (Wang et al., 2003). The heritabilities for OBF, MBF, IBF, CBF, SBF, and IMF were 0.63, 0.45, 0.53, 0.48, 0.44, and 0.69, respectively. The genetic correlations of OBF, MBF, and IBF with IMF were 0.36, 0.16, and 0.28, respectively, and the genetic correlations of CBF and SBF with IMF were 0.25 and 0.27, respectively. Genetic correlations between OBF and MBF, OBF and IBF, and MBF and IBF were 0.43, 0.45, and 0.67, respectively. Results demonstrate that individual backfat layers are highly heritable, of similar magnitude to total backfat, and have similar genetic correlations with IMF. Individual backfat layers could become candidate traits for implementation into a multiple-trait genetic evaluation to improve IMF, while minimizing the detrimental effect on total backfat depth. (+info)
Extragonadal aromatization increases with time after ovariectomy in rats.
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BACKGROUND: The circulating estrogen concentration elevated gradually along with time after ovariectomy in rats. To explore the source of the increased circulation estrogen, the extragonadal aromatization as well as the synthesis of androgen in the adrenal cortex of the ovariectomized rats was evaluated. METHODS: Female rats were divided into twelve groups: 1 month after ovariectomy (OVX1M), OVX2M, OVX3M, OVX4M, OVX5M, OVX6M; intact 1 month (INT1M), INT2M, INT3M, INT4M, INT5M, INT6M. The blood concentration of testosterone (T) was measured by radioimmunoassay. The mRNA expressions of P450 aromatase in the liver and subcutaneous abdominal (SA) adipose as well as the adrenal cytochrome P450 17 alpha hydroxylase/lyase (P450c17) were semiquantified by RT-PCR. The P450 aromatase protein expressions in the liver and SA adipose were detected by Western blot. RESULTS: The blood E2 concentrations increased gradually along with time after ovariectomy in the rats. The 58-kDa aromatase protein and mRNA expressions normalized to beta-actin in the OVX6M rats' SA adipose tissues showed higher levels than those from corresponding tissues in the INT6M (p < 0.05). And the ratios of aromatase mRNA and protein to beta-actin in the OVX6M rats' liver tissues increased significantly compared with those in the OVX1M rats (p < 0.05). The ratio of adrenal P450c17 to beta-actin in the OVX6M increased markedly, and was higher than OVX1M (p < 0.05), though the blood concentration of T decreased significantly in all the ovariectomized rats (p < 0.05). CONCLUSION: Both the subcutaneous abdominal adipose tissues and the liver tissues contributed to the extragonadal aromatisation to promote the circulating E2 levels in the rats along with time after ovariectomy; the adrenal compensation might also be activated naturally. (+info)
Fatty acid indices of stearoyl-CoA desaturase do not reflect actual stearoyl-CoA desaturase enzyme activities in adipose tissues of beef steers finished with corn-, flaxseed-, or sorghum-based diets.
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We hypothesized that stearoyl-CoA desaturase (SCD) enzyme activity would not correlate with fatty acid indices of SCD activity in steers fed different grains. Forty-five Angus steers (358 +/- 26 kg BW) were individually fed for 107 d diets differing in whole cottonseed (WCS) supplementation (0, 5, or 15% of DM) and grain source (rolled corn, flaxseed plus rolled corn, or ground sorghum grain) in a 3 x 3 factorial arrangement. Flaxseed- and corn-fed steers had greater (P < 0.01) G:F (0.119 and 0.108, respectively) than sorghum-fed steers (0.093). Marbling score was decreased by WCS (P = 0.04), and LM area was decreased (P < 0.01) by sorghum. Plasma 14:0, 16:0, 16:1n-7, and 18:2n-6 were greatest in corn-fed steers, whereas plasma 18:3n-3 and 20:5n-3 were greatest in the flax-seed-fed steers (P < 0.01). Plasma 18:1trans-11 was least in sorghum-fed steers, and plasma cis-9,trans-11 CLA was barely detectable, in spite of high intestinal mucosal SCD enzyme activity (118 to 141 nmol*g tissue(-1).7 min(-1)). Interfascicular (i.f.) and s.c. cis-9,trans-11 CLA remained unchanged (P > or = 0.25) by treatment, although 18:1trans-11 was increased (P < or = 0.02) in steers fed corn or flaxseed. Steers fed flaxseed also had greater (P < 0.01) i.f. and s.c. concentrations of 18:3n-3 than steers fed the other grain sources. Oleic acid (18:1n-9) was least and total SFA were greatest (P < 0.01) in i.f. adipose tissue of steers fed 15% WCS. Lipogenesis from acetate in s.c. adipose tissue was greater (P < 0.01) in flaxseed-fed steers than in the corn- or sorghum-fed steers. Steers fed flaxseed or corn had larger i.f. mean adipocyte volumes (P < 0.01) than those fed sorghum and tended (P = 0.07) to have larger s.c. adipocyte volumes. Several fatty acid indices of SCD enzyme activity were decreased (P < or = 0.03) by WCS in i.f. adipose tissue, including the 18:2cis-9,trans-11/ 18:1trans-11 ratio. The 18:2cis-9,trans-11/18:1trans-11 ratio also tended to be decreased (P = 0.09) in s.c. adipose tissue by flaxseed; however, SCD enzyme activities in i.f. and s.c. adipose tissue were not affected by dietary WCS (P > or = 0.47) or grain source (P > or = 0.37). Differences in SFA seemed to be independent of SCD enzyme activity in both adipose tissues, suggesting that duodenal concentrations of fatty acids were more important in determining tissue fatty acid concentrations than endogenous desaturation by SCD. (+info)
The fatty acid composition of muscle fat and subcutaneous adipose tissue of pasture-fed beef heifers: influence of the duration of grazing.
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Our objective was to determine the effect of the duration of grazing before slaughter on the fatty acid composition of muscle fat and s.c. adipose tissue (SAT) of beef heifers. Sixty crossbred Charolais heifers (n = 15 per treatment) were assigned randomly to one of four dietary treatments: 45 animals (Treatments 1, 2, and 3, respectively) were housed at the beginning of the experiment, and 15 (Treatment 4) were fed at pasture. Two groups of 15 heifers were moved to pasture 40 d (Treatment 2) and 99 d (Treatment 3) before slaughter, respectively, resulting in preslaughter grazing periods of 0, 40, 99, or 158 d for Treatments 1, 2, 3, and 4, respectively. Before grazing the predominantly perennial ryegrass pasture, animals were housed and offered grass silage ad libitum and 3 kg of concentrate diet (650 g of grass silage/kg of total DMI). After slaughter, the fatty acid profile of the neutral (NL) and polar lipid (PL) fractions of muscle fat from the LM and the total lipids from SAT were analyzed by gas chromatography. Duration of grazing showed a quadratic tendency on mean carcass weight (P = 0.08), but did not affect growth (P = 0.27) or the lipid content (P = 0.13) of the LM. Increasing the duration of grazing led to a linear increase (P < 0.001) in the concentration (on fresh-tissue basis) of CLA in muscle fat (from 11.80 to 17.75 mg/100 g of muscle in NL, and from 0.52 to 0.82 mg/100 of g muscle in PL) and in SAT (from 3.98 to 10.23 mg/g of SAT; P < 0.001), and increased the concentration of C18:1trans-11 in both muscle fat fractions (P < 0.001) and in SAT (P < 0.001). In the total muscle lipids, the polyunsaturated to saturated fatty acid ratio (P:S) increased from 0.12 to 0.15 with increased duration of grazing following a linear (P < 0.05) and cubic pattern (P < 0.05). Increasing the duration of grazing led to a linear decrease in the n-6:n-3 ratio of muscle fat from 2.00 to 1.32 (P < 0.001), and from 2.64 to 1.65 in the SAT lipids (P < 0.001), mainly as a consequence of the increased concentration of C18:3n-3. It is concluded that muscle fat and SAT fatty acid profile was improved from a human health perspective by pasture feeding, and that this improvement depended on the duration of grazing. (+info)
Increase of microcirculatory blood flow enhances penetration of ciprofloxacin into soft tissue.
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The present study addressed the effect of microcirculatory blood flow on the ability of ciprofloxacin to penetrate soft tissues. Twelve healthy male volunteers were enrolled in an analyst-blinded, clinical pharmacokinetic study. A single intravenous dose of 200 mg of ciprofloxacin was administered over a period of approximately 20 min. The concentrations of ciprofloxacin were measured in plasma and in the warmed and contralateral nonwarmed lower extremities. The microdialysis technique was used for the assessment of unbound ciprofloxacin concentrations in subcutaneous adipose tissue. Microcirculatory blood flow was measured by use of laser Doppler flowmetry. Warming of the extremity resulted in an increase of microcirculatory blood flow by approximately three- to fourfold compared to that at the baseline (P < 0.05) in subcutaneous adipose tissue. The ratio of the maximum concentration (C(max)) of ciprofloxacin for the warmed thigh to the C(max) for the nonwarmed thigh was 2.10 +/- 0.90 (mean +/- standard deviation; P < 0.05). A combined in vivo pharmacokinetic (PK)-in vitro pharmacodynamic (PD) simulation based on tissue concentration data indicated that killing of Pseudomonas aeruginosa (ATCC 27853 and two clinical isolates) was more effective by about 2 log(10) CFU/ml under the warmed conditions than under the nonwarmed conditions (P < 0.05). The improvement of microcirculatory blood flow due to the warming of the extremity was paralleled by an increased ability of ciprofloxacin to penetrate soft tissue. Subsequent PK-PD simulations based on tissue PK data indicated that this increase in tissue penetration was linked to an improved antimicrobial effect at the target site. (+info)
Increased lipolysis of subcutaneous abdominal adipose tissue and altered noradrenergic activity in patients with Cushing's syndrome: an in-vivo microdialysis study.
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Cushing's syndrome is associated with typical central redistribution of adipose tissue. The aim of the study was to assess lipolysis and catecholamines and their metabolites in subcutaneous abdominal adipose tissue using an in-vivo microdialysis technique. Nine patients with Cushing's syndrome and nine age-, gender- and body mass index (BMI)-matched control subjects were included in the study. Local glycerol concentrations were significantly increased in subcutaneous adipose tissue of patients with Cushing's syndrome (p<0.001). Plasma noradrenaline, dihydroxyphenylglycol and dihydroxyphenylalanine were decreased in patients with Cushing's syndrome (p<0.02, p<0.05, and p<0.02, respectively). Adrenaline, noradrenaline, dihydroxyphenylglycol and dihydroxyphenylalanine concentrations in subcutaneous abdominal adipose were non-significantly higher in patients with Cushing's syndrome. In conclusion, we showed that lipolysis in subcutaneous adipose tissue of patients with Cushing's syndrome is significantly increased as compared to healthy subjects. This finding together with non-significantly increased local catecholamine concentrations in these patients suggests a possible link between increased lipolysis and catecholaminergic activity in subcutaneous adipose tissue. (+info)
Differences in transport of fatty acids and expression of fatty acid transporting proteins in adipose tissue of obese black and white women.
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We have reported that the rate of de novo triglyceride (TG) synthesis by omental, but not subcutaneous, adipose tissue was higher in African-American women (AAW) than in Caucasian women (CAW). The purpose of this study was to explore the potential mechanisms underlying this increase. Toward that end, we determined the activities of key enzymes in the pathway of TG synthesis, the rates of uptake of fatty acids by adipocytes, mRNA and protein levels of the fatty acid-transporting proteins FAT/CD36 and FATP, and mRNA and protein levels of PPARgamma in omental fat of AAW and CAW. The results showed 1) no difference in the activity of phosphofructokinase, glycerol-3-phosphate dehydrogenase, or diacylglycerol acyltransferase; 2) a higher rate of fatty acid uptake by adipocytes of the AAW; 3) an increase in the mRNA and protein levels of CD36 and FATP4 in the fat of the AAW; and 4) an increase in the mRNA and protein levels of PPARgamma, which can stimulate the expression of CD36 and FATP. These results suggest that the increase in the transport of fatty acid, which is mediated by the overexpression of the transport proteins in the omental adipose tissue of the AAW, might contribute to the higher prevalence of obesity in AAW. (+info)
Cytological diagnosis of subcutaneous fat necrosis of newborn: a case report.
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Cytological findings of subcutaneous fat necrosis of the newborn, a rare and transient disorder of neonates, is described in a 20-day-old male baby, who presented with a 2-week history of firm, erythematous nodules and plaques on the back and upper arms. (+info)