Retroperitoneal White Adipose Tissue Weight Research Articles

Transgenerational Evaluation of Elateriospermum tapos Extracts on the Male Offspring of Obesity-Induced Sprague Dawley Rats

Obesity has been considered as a great public health concern, that has spread in both economic and poor resources countries. This study aimed to investigate the effect of Elateriospermum tapos supplementation on the male offspring of female obesity-induced Sprague Dawley (SD) rats at weaning and adult age. A total of thirty (30) female and fifteen (15) male Sprague Dawley rats (N=45) were purchased for this study. Of the 30 female rats, six (n=6) were randomly selected as the control group (CG) and fed separately with male on standard chow diet, while the remaining rats (n=24) were fed on a high-fat diet for 5 weeks. The obese group were further randomly divided into 4 groups, positive control group (PG), orlistat treatment (DG) at 200 mg/kg, treatment 1 (TX1, 200 mg/kg E. tapos seed) and treatment 2 (TX2, 200 mg/kg E. tapos shell) for 6 weeks. One male pup from each dam was culled at weaning (postnatal day 21 (PND21)) and adulthood (12 weeks). The liver, kidney, retroperitoneal white adipose tissue (RpWAT) and brown adipose tissue (BAT) were collected for histopathological study. Serum lipid profiles, liver enzyme activities and creatinine were measured. The bodyweight of male offspring from treatment 1 (MTX1) and 2 (MTX2) was significantly lower (P<0.05) compare to MNG group. The RpWAT weight in MTX1 and MTX2 for adult offspring also were significantly lower (P<0.05) compared to MPG. The histopathological examination of liver in MCG, MDG, MTX1, and MTX2 showed normal hepatocytes while the MPG group showed the presence of ballooning cell and hypertrophy of adipocytes was also observed in MPG group compared to another group’s rat. The E. tapos extracts from the shell have greater therapeutic potential on maternal obesity in short and long term treatment.

Maternal supplementation of α-linolenic acid in normal and protein-restricted diets modulate lipid metabolism, adipose tissue growth and leptin levels in the suckling offspring.

Lipid quantity and quality have been shown to affect serum cholesterol, adipose and serum leptin levels during prenatal and postnatal dietary supplementation of adult rats. Maternal protein deficiency during pregnancy and lactation also affects polyunsaturated fatty acid (PUFA) levels in the offspring. The aim of the present study was to analyze the effect of α-linolenic acid (ALA; n-3) on n-3 PUFA accretion, lipid profile, leptin levels and adipose growth in normal and protein-restricted (deficient) dams and their suckling pups. Garden cress oil rich in ALA (32%) was supplemented in the normal and protein-restricted (10%) diets and fed to rats for 8 weeks prior to gestation and during lactation. PUFA, cholesterol, triglycerides, leptin levels and retroperitoneal white adipose tissue weight (WAT) of the dams and the pups were analyzed at 3 weeks after delivery. The serum cholesterol levels were remarkably decreased (p < 0.01), and the n-3 PUFA levels were markedly increased (p < 0.05) in the pups of lactating normal and protein-deficient dams supplemented with ALA. Triglycerides were unaltered in the dams and the pups of different dietary groups. Serum leptin levels and relative WAT weights were lower (p < 0.01) in the pups of the ALA-supplemented normal and protein-deficient dams. Maternal supplementation of ALA in normal and protein-restricted diets modulates n-3 PUFA levels, cholesterol, leptin levels and also adipose growth in the suckling offspring.

KK/Ta Mice Administered Lactobacillus plantarum Strain No. 14 Have Lower Adiposity and Higher Insulin Sensitivity.

Excess accumulation of white adipose tissue can lead to obesity-related metabolic abnormalities such as insulin resistance. We previously reported that intragastric administration of Lactobacillus plantarum No. 14 reduced adipocyte size in diet-induced obese C57BL/6 mice. The present study tested whether L. plantarum No. 14 affects adiposity and insulin sensitivity in an animal model of type-2 diabetes mellitus. Male KK/Ta mice were fed a normal-fat diet and intragastrically given L. plantarum No. 14 (108 CFU/mouse) or vehicle daily for 10 weeks. Interscapular brown adipose tissue and inguinal, mesenteric, and retroperitoneal white adipose tissue weights, serum leptin and insulin concentrations, and insulin resistance index (HOMA-IR) were significantly lower in L. plantarum No. 14-fed mice than in vehicle-fed mice. The sum of the inguinal, epididymal, mesenteric and retroperitoneal white adipose tissue weights correlated with serum leptin and non-esterified fatty acid concentrations and HOMA-IR. The mesenteric adipose tissue mRNA levels of monocyte chemoattractant protein-1 and tumor necrosis factor-α were significantly lower in L. plantarum No. 14-fed mice than in vehicle-fed mice. Mesenteric adipose tissue weight correlated with interleukin-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α mRNA levels. HOMA-IR correlated with monocyte chemoattractant protein-1 and tumor necrosis factor-α mRNA levels. These data suggest that L. plantarum No. 14 prevents the development of insulin resistance, which is at least partly attributable to the prevention of obesity, in KK/Ta mice.

A soyabean diet does not modify the activity of brown adipose tissue but alters the rate of lipolysis in the retroperitoneal white adipose tissue of male rats recovering from early-life malnutrition

Nutritional recovery with a soyabean diet decreases body and fat weights when compared with a casein diet. We investigated whether the reduced adiposity observed in rats recovering from early-life malnutrition with a soyabean diet results from alterations in lipid metabolism in white adipose tissue (WAT) and/or brown adipose tissue (BAT). Male rats from mothers fed either 17 or 6% protein during pregnancy and lactation were maintained on 17% casein (CC and LC groups), 17% soyabean (CS and LS groups) or 6% casein (LL group) diets over 60d. The rats maintained on a soyabean diet had similar relative food intakes, but lower body and retroperitoneal WAT weights and a reduced lipid content in the retroperitoneal WAT. The insulin levels were lower in the recovered rats and were elevated in those fed a soyabean diet. Serum T3 concentration and uncoupling protein 1 content in the BAT were decreased in the recovered rats. The thermogenic capacity of the BAT was not affected by the soyabean diet. The lipogenesis rate in the retroperitoneal WAT was similar in all of the groups except for the LL group, which had exacerbated lipogenesis. The enhancement of the lipolysis rate by isoproterenol was decreased in white adipocytes from the soyabean-recovered rats and was elevated in adipocytes from the soyabean-control rats. Thus, in animals maintained on a soyabean diet, the proportions of fat deposits are determined by the lipolysis rate, which differs depending on the previous nutritional status.

Reverse Feeding Suppresses the Activity of the GH Axis in Rats and Induces a Preobesogenic State

Reversed feeding (RF) is known to disrupt hormone rhythmicity and metabolism. Although these effects may be mediated in part by phase inversion of glucocorticoid secretion, the precise mechanism is incompletely characterized. In this study, we demonstrate that acute nocturnal food deprivation in male rats suppressed the amplitude of spontaneous GH secretion during the dark phase by 62% (P < 0.001), without affecting baseline secretion. Prolonged RF, which reduced pituitary weight (by 22%; P < 0.05), also suppressed GH pulse height sufficiently to reduce skeletal growth (by 4-5%; P < 0.01) and terminal liver weight (by 11%; P < 0.001). Despite this suppression of the GH axis, proportionate adiposity was not elevated, probably due to the accompanying 16% reduction in cumulative food intake (P < 0.01). We demonstrate that RF also resulted in phase inversion of core clock gene expression in liver, abdominal white adipose tissue (WAT) and skeletal muscle, without affecting their expression patterns in the suprachiasmatic nucleus. In addition, RF resulted in phase inversion of hepatic peroxisome proliferator-activated receptor γ2 mRNA expression, a 3- to 5-fold elevation in fatty acid synthase mRNA in WAT in both light- and dark-phase samples (P < 0.01) and an elevation in muscle uncoupling protein 3 mRNA expression at the beginning of the light phase (P < 0.01). Consumption of a high-fat diet increased inguinal (by 36%; P < 0.05) and retroperitoneal WAT weight (by 72%; P < 0.01) only in RF-maintained rats, doubling the efficiency of lipid accumulation (P < 0.05). Thus, RF not only desynchronizes central and peripheral circadian clocks, and suppresses nocturnal GH secretion, but induces a preobesogenic state.

Exercise training in rats impairs the replenishment of white adipose tissue after partial lipectomy

The aim of this study was to evaluate the effect of exercise training on the metabolism of rats following the partial removal of fat pads. Three-month-old male Wistar rats were subjected to the partial removal (L) of retroperitoneal white adipose tissue (RET) and epididymal white adipose tissue (EPI), or a sham operation (Sh). Seven days after surgery, both sets of rats were subdivided into exercised (LE or ShE) (swimming 90 min/day, 5 days/week, 6 weeks) and sedentary (LS or ShS) groups. Partial removal of the fat pads increased the lipogenesis rates in both the RET and EPI and decreased the weight and lypolysis rate of the EPI, while the RET weight was not significantly affected by lipectomy. In both lipectomized and sham-operated groups, exercise training caused a reduction in carcass lipid content, food intake, RET and EPI weights, and RET lipogenesis rate. On the other hand, the exercise training increased the percentage of diet-derived lipid accumulation in both tissues, either in sham and lipectomized rats. These results confirmed that regrowth is not uniform and depends on the particular fat pad that is excised. They also demonstrated that exercise training following the partial removal of fat pads modified adipose tissue metabolism, impaired the replenishment of adipose tissue, and decrease body adiposity.

Vitamin A regulates obesity in WNIN/Ob obese rat; independent of stearoyl-CoA desaturase-1

Stearoyl-CoA desaturase 1 (SCD1), an important enzyme involved in monounsaturated fatty acid biosynthesis is a key player in energy homeostasis. Here, we tested the impact of vitamin A on hepatic and adipose tissue SCD1 expression and adiposity per se, using an obese mutant rat strain namely, WNIN/Ob developed at National Center for Laboratory Animal Sciences of National Institute of Nutrition, India. Seven months-old 24 male lean and obese rats of WNIN/Ob strain were divided into two groups; each group was subdivided into two subgroups having 6 lean and 6 obese rats and received diets containing either 2.6mg or 129mg vitamin A/kg diet for two months. Feeding of high (but non-toxic) doses of vitamin A resulted in significant reduction in body weight gain, and retroperitoneal white adipose tissue weight (RPWAT) in obese rats. Further, vitamin A feeding resulted in augmented expression of SCD1 in liver and RPWAT of lean rats, while no such effect was seen in obese rats. Taken together, the present data suggest that vitamin A decreases body weight gain in obese rat model independent of SCD1 gene regulation.

Is Leptin a Key Factor which Develops Obesity by Ovariectomy?

Withdrawal of estrogen by ovariectomy increases adiposity, but decreases the circulating levels of the ob gene product, leptin, which inhibits food intake. The reduction of circulating leptin levels may thus play an important role in the induction of obesity by ovariectomy. To examine this hypothesis, body weight change by ovariectomy was investigated in leptin-deficient genetically obese (ob/ob) mice with leptin supplement. Prior to the operation, obese (ob/ob) female mice were treated with intraperitoneal administration of recombinant mouse leptin (1.0 microg/g body weight/day) for 8 days. Then, half of the leptin-treated mice and their lean littermates were bilaterally ovariectomized and their body weight changes were observed for 56 days. From 16 days after the operation, a significant increase in body weight by ovariectomy was observed only in lean mice without leptin treatment. From 44 days, a significant body weight gain by ovariectomy was observed in leptin-treated obese mice. Ovariectomy significantly increased retroperitoneal white adipose tissue weight in their lean littermates, but not in leptin-treated obese mice. It was suggested that the reduction of circulating leptin levels may play an important role in the increases of acute phase body weight gain by ovariectomy, but during static phase, the direct effects of estrogen withdrawal may appear independent of leptin-mediated effects.

Resistance to aging-associated obesity in capsaicin-desensitized rats one year after treatment.

Previous studies demonstrated reduced weight of abdominal white adipose tissue depots and of carcass fat in capsaicin-desensitized (Cap-Des) rats up to 8 months after treatment. The objective of the present study was to find out whether aging-associated obesity and hyperplasia of retroperitoneal white adipose tissue was prevented in older (13.5 months old) Cap-Des rats, one year after treatment with Cap (done when they were 1.5 months old). The prevalence of obesity is known to increase in rats by this age. Abdominal white adipose tissue depots weighed less in old Cap-Des rats, both epididymal (9% less) and retroperitoneal (30% less). The number of mature white adipocytes was 28% less in the retroperitoneal depot but was not significantly different in the epididymal depot. Adipocyte size was not different. Carcass fat was less, both total and as percent of body weight. Food intake was normal for their reduced body size. The exponential increase in retroperitoneal white adipose tissue weight characteristic of aging rats that are becoming obese was virtually absent in Cap-Des rats. We conclude that lack of function of capsaicin-sensitive afferent autonomic nerves, known to be destroyed in Cap-Des rats, results in an alteration in energy balance conducive to leanness. We suggest that the attenuated age-associated increase in circulating CGRP (derived mainly from capsaicin-sensitive nerves) in the Cap-Des rat results in a lower degree of aging-associated insulin-resistance, hence in a lesser degree of obesity.

Effects of ovariectomy on thermogenesis in brown adipose tissue and liver in Syrian hamsters

Weight gain in ovariectomized Syrian hamsters occurs without increased food intake, which suggests that metabolic efficiency may be enhanced through a reduction in energy expenditure. We examined the effect of ovariectomy on metabolic activity in brown adipose tissue and liver. Four groups of hamsters (n = 13, each) were killed 0, 2, 4, or 16 weeks following ovariectomy. Ovariectomized hamsters rapidly gained weight without overeating. Body weights stabilized after 8 weeks and remained 12–17% above sham-operated control weights for the duration of the experiment. Weight gain in the hamsters ovariectomized for 16 weeks was characterized by significant increases in retroperitoneal white adipose tissue weight and carcass lipid content. Similar trends were seen in 2-week and 4-week ovariectomized animals. There were no differences in interscapular brown adipose tissue weight, protein content, DNA content, or norepinephine (NE) content among sham-operated and 2-, 4-, or 16-week ovariectomized hamsters, indicating that ovariectomy had no effect on brown adipose tissue growth. Similarly, there was no difference in either sympathetic nervous system activity (estimated by the rate of NE turnover) or mitochondrial GDP binding among the four groups of hamsters. In contrast, hepatic cytochrome P-450 activity was significantly reduced 2, 4, and 16 weeks after ovariectomy. These results suggest that reduced thermogenic activity in liver, but not in brown adipose tissue, could contribute to the weight gain in Syrian hamsters after ovariectomy.

Regional differences in fat pad responses to short days in Siberian hamsters

Siberian hamsters exhibit decreased body weight and fat after initial exposure to short photoperiods and increased body weight and fat after extended short photoperiod exposure. The purpose of the present experiments was to determine if uniform changes in white adipose tissue (WAT) pad weights and lipid metabolism correspond to these short photoperiod-induced changes in body fat. Carcass lipid content and testes and fat pad weights [retroperitoneal WAT (RWAT), epididymal WAT (EWAT), and inguinal and dorsal subcutaneous WAT, respectively] were decreased in male hamsters relative to their long day counterparts after 6 and 12 wk of short-day exposure. Moreover, EWAT and RWAT weight, EWAT specific lipoprotein lipase activity, and specific and total lipogenesis were disproportionately decreased relative to the subcutaneous fat pads. The changes in fat pad weight and metabolism were generally reversed coincident with the return to a long-day-like reproductive status after prolonged short-day exposure (24 and 30 wk). In a less detailed experiment, female Siberian hamsters had decreased body, fat pad, and uterine weights after 6 wk of short-day exposure; however, no fat pad-specific changes in weight were observed. The results of these experiments demonstrate that short-day-exposed male Siberian hamsters may be a useful model for examining mechanisms underlying fat pad-specific responses. In addition, gender appears to influence the pattern of short-day-induced lipid depletion in this species.

Effect of a high-fat diet on firing rate of sympathetic nerves innervating brown adipose tissue in anesthetized rats

Three experiments have examined the effects of ad lib and forced intake of a high-fat diet on sympathetic firing rate to brown adipose tissue. Seven days after beginning of ad lib intake of either a low-fat or high-fat diet, sympathetic activity was not significantly different in either group nor was it significantly different from the values obtained in animals measured at the switch from the chow to a semisynthetic high- or low-fat diet. After 22 days on the semisynthetic diet, however, the sympathetic firing rate of animals eating the high-fat diet had decreased nearly 25% and was significantly lower than the animals maintained on the semisynthetic low-fat diet or animals studied at the transition from the chow to the low-fat diet. In a second experiment animals were tube-fed for 3, 6 or 9 weeks on a high- or low-fat diet. Sympathetic firing rate of the rats eating the low-fat diet was higher at all three times, but the difference decreased with longer feeding. To eliminate differences in food intake, animals were tube-fed a moderate- or high-fat liquid diet three times a day for six days. The 80 kcal/day intake produced a steady weight gain in both groups. Liver weight, retroperitoneal white adipose tissue weight, and interscapular brown adipose tissue weight were all significantly greater in the animals fed the high-fat diet. Sympathetic firing rate, however, was significantly lower in the animals fed the high-fat semisynthetic diet as compared to animals fed the moderate-fat diet. These data show the high-fat diets are associated with a reduction in sympathetic activity to brown adipose tissue.