Biomedical subjects

Julian Swierczynski

Publications and source records attributed to Julian Swierczynski.

At least 19 recordsLinked to original sources

PubMed2007

The potential role of sterol regulatory element binding protein transcription factors in renal injury.

The disturbed lipid metabolism is a permanent finding in renal failure. It is supposed to be a main reason for the accelerated atherosclerosis and high cardiovascular and cerebrovascular mortality of patients with renal failure. Sterol regulatory element binding proteins (SREBPs) are the transcription factors involved in the regulation of lipid homeostasis. They are responsible for the transcription activation of genes associated with the synthesis of fatty acids, triglycerides, and cholesterol. SREBP-1 gene expression in adipose tissue and SREBP-2 in liver are significantly elevated in renal failure. This is accompanied with the up-regulation of genes encoding enzymes of both fatty acids and cholesterol synthesis and significant serum lipid enhancement. Moreover, it has been shown that a destructive accumulation of lipids in the kidney structures is associated with enhanced kidney SREBP gene expression and increased lipid production. This was found even in the absence of any abnormalities in serum lipids. One may suppose that SREBP transcription factors play an important role in disturbed lipid metabolism in renal failure.

Disease Progression↗

PubMed2006

Up-regulation of NPY gene expression in hypothalamus of rats with experimental chronic renal failure.

Anorexia is possibly one of the most important causes of malnutrition in uremic patients. The cause of this abnormality is still unknown. Considering that: (a) NPY is one of the most important stimulants of food intake; (b) eating is a central nervous system regulated process and (c) NPY is expressed in hypothalamus, we hypothesized that the decrease of NPY gene expression in the hypothalamus could be an important factor contributing to anorexia associated with uremic state. In contrast to the prediction, the results presented in this paper indicate that the NPY gene expression in the hypothalamus of chronic renal failure (CRF) rats was significantly higher than in the hypothalamus of control (pair-fed) rats. Moreover, we found that serum NPY concentration in CRF rats was higher than in control (pair-fed) animals. The increase of plasma NPY concentration in CRF rats may be due to the greater synthesis of the neuropeptide in liver, since higher level of NPY mRNA was found in liver of CRF rats. The results obtained revealed that experimental chronic renal failure is associated with the increase of NPY gene expression in hypothalamus and liver of rats.

Animals↗

PubMed2006

Increased gene expression of liver SREBP-2 in experimental chronic renal failure.

Sterol regulatory element-binding protein-2 (SREBP-2) is a transcription factor regarded as the main regulator of cholesterol homeostasis. Therefore, increased level of SREBP-2 could be responsible for hypercholesterolemia, which is observed in experimental chronic renal failure (CRF). This study was designed primary to evaluate the impact of experimental CRF (5/6 nephrectomy model) on rat liver SREBP-2 gene expression. In CRF rats, a twofold increase in SREBP-2 mRNA level, as well as in mature SREBP-2 protein abundance was found, when compared to control animals. It was associated with enhanced activity and mRNA abundance of liver HMG-CoA reductase, a rate-limiting enzyme for cholesterol biosynthesis. A twofold increase in liver cholesterologenesis rate was also noted. We conclude that experimental CRF is associated with increased liver SREBP-2 gene expression. This is probably the cause for enhanced HMG-CoA reductase gene expression and, consequently, for increase in liver cholesterol synthesis in CRF rats. Despite increased SREBP-2 gene expression we found LDL-receptor mRNA level to be lower than in controls, suggesting SREBP-2 independent mechanisms of LDL-receptor transcriptional regulation in CRF rats. Enhanced cholesterol synthesis and decreased LDL-receptor mRNA level are probably responsible for an almost fourfold increase in serum cholesterol concentration in CRF rats.

Animals↗

PubMed2006

Evidence that triiodothyronine decreases rat serum leptin concentration by down-regulation of leptin gene expression in white adipose tissue.

Conflicting results have been reported regarding the effect of triiodothyronine (T(3)) on serum leptin and adipose tissue leptin gene expression in human and animals. The aim of the present study was to evaluate the effect of administration of increasing doses of T(3) on serum leptin concentration and on leptin mRNA abundance in white adipose tissue of rats. The results presented in this paper indicate that administration of single different doses of T(3) to euthyroid rats resulted dose dependent increases of serum total T(3) concentrations which are associated with a decrease in white adipose tissue leptin mRNA level. The leptin mRNA level in white adipose tissue was negatively correlated with serum total T(3) concentration (r=-0.8, p<0.001). Like white adipose tissue leptin mRNA level, serum leptin concentration decreased after T(3) administration, and was also negatively correlated with the serum T(3) concentration (r=-0.8, p<0.001). In contrast, administration of T(3) to the same rats led to a significant increase in white adipose tissue expression of the malic enzyme gene (malic enzyme activity and malic enzyme mRNA level), a known target gene for T(3). The results indicate that T(3) exerts a selective inhibitory effect on white adipose tissue leptin gene expression in vivo. A conclusion is that T(3) decreases rat serum leptin concentration by down-regulation of leptin gene expression in white adipose tissue.

Adipose Tissue↗

PubMed2006

Accumulation of poly(ADP-ribose) polymerase inhibitors in children with chronic renal failure.

Nicotinamide, N-methyl-2-pyridone-5-carboxamide (Met2PY) and N-methyl-4-pyridone-3-carboxamide (Met4PY) are biological metabolites of the intracellular coenzyme nicotinamide adenine dinucleotide (NAD) that can potentially inhibit poly(ADP-ribose) polymerase 1 (PARP-1; DNA repair enzyme). Our research was aimed at establishing whether chronic renal failure (CRF) in children leads to the elevation of plasma NAD metabolites sufficient to inhibit PARP-1 activity. Nicotinamide, Met2PY and Met4PY plasma and erythrocyte concentrations were measured in 25 children with CRF and in 19 healthy children. The effect of these NAD metabolites on PARP-1 activity was studied in vitro. We found that plasma concentration of all NAD metabolites (nicotinamide, Met2PY, Met4PY) in children with CRF could reach the concentration of 2, 30 and 10 microM as compared to 0.2, 1 and 0.5 microM, respectively, in healthy children. The concentration of nicotinamide metabolites correlated positively with plasma creatinine concentration and negatively with creatinine clearance in children with CRF. We found that Met2PY, Met4PY and nicotinamide inhibited in vitro PARP-1 activity with IC50 values of 2.1, 0.18 and 0.12 mM, respectively. Our data indicate that NAD metabolites accumulate in plasma of children with CRF and their combined effect could lead to the inhibition of PARP-1 activity. NAD metabolites could be particularly harmful in children due to higher DNA turnover than in adults.

Adolescent↗

PubMed2006

Gender- and age-related changes in 6-phosphogluconate dehydrogenase gene expression in white adipose tissue of rats (Rattus norvegicus) are not related to serum testosterone concentration.

Previously, we have shown that the age-related changes in 6-phosphogluconate dehydrogenase (6PGDH) activity depend on sex, and that oestradiol is playing a crucial role in the regulation of 6PGDH gene expression in rat liver, but not in other tissues [Pankiewicz, A., Sledzinski, T., Nogalska, A., Swierczynski, J., 2003. Tissue specific, sex and age-related differences in the 6-phosphogluconate dehydrogenase gene expression. Int. J. Biochem. Cell Biol. 35, 235-245.]. To complete the knowledge on the influence of sex hormones on 6PGDH activity, experiments have been performed on the effect of testosterone on 6PGDH gene expression in rat white adipose tissue and liver. The results presented here disclosed that in young male rats high serum testosterone concentration was associated with high white adipose tissue 6PGDH activity. After orchidectomy, a decrease in serum testosterone concentration (both in young and old rats) was observed. In contrast, no changes in white adipose tissue and liver 6PGDH activity were found. In female rats, both young and old, serum testosterone concentration was below the limit of detection, whereas 6PGDH activity was much higher in young than in old animals. Moreover, the testosterone administration to 9-month old male rats (which displayed much lower serum testosterone concentration that young animals) resulted in no effect on 6PGDH activity either in WAT or in the liver. In conclusion, the results presented in this paper indicate that testosterone does not play any role in the age- and gender-related differences in 6PGDH gene expression in white adipose tissue.

Adipose Tissue↗

PubMed2006

Interrelationship between uremic toxicity and oxidative stress.

Uremic syndrome is associated with several metabolic disturbances. Oxidative stress is an important factor involved in the pathologic mechanism of these changes. The goal of this study was to understand the relationship between oxidative stress markers and two compounds included among uremic toxins. Two independent studies were performed, one with 29 peritoneal dialysis patients and the other with 43 predialysis subjects. In both groups of patients, known oxidative stress markers, malonyldialdehyde (MDA) and carbonyl groups (CG) formation were measured. Additionally, in the predialysis group, glutathione in erythrocytes (GSH) was estimated. In peritoneal dialysis patients, the concentration of advanced glycation end products (AGEs) was found to be significantly increased and correlated with both markers of oxidative stress. In predialysis patients, the increment of newly described uremic toxin purine nucleotide end products (Me2PY and Me4PY) were found and significant correlation was observed between both compounds versus MDA (positive) and GSH (negative). This relationship was visible especially in patients with more advanced renal failure. CG concentration was within the normal values and did not show any correlation with estimated toxin concentrations. In summary, results of both studies suggest that the interrelationship between uremic toxicity and oxidative stress is an important component of uremic syndrome. Nevertheless, further complex studies are needed to elucidate closer pathogenic links.

Aged↗

PubMed2005

Leptin decreases lipogenic enzyme gene expression through modification of SREBP-1c gene expression in white adipose tissue of aging rats.

Aging is associated with a significant reduction of lipogenic enzyme gene expression and lipogenesis in white adipose tissue (WAT). The age-related increase of lep gene expression could be, in part, responsible for these changes. Considering that sterol regulatory element binding protein 1c (SREBP-1c) plays an important role in regulation of lipogenic enzyme gene expression, it is likely that the age-related decrease of WAT lipogenic potential could be a consequence of the inhibition of SREBP-1c gene expression by leptin. We determined whether the increase of lep gene expression would account for the age-related decrease in SREBP-1c and its direct target, main lipogenic enzymes acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), by assaying the messenger RNA (mRNA) levels of SREBP-1c, FAS, ACC, and leptin in WAT of 2-month-old (young) and 20-month-old (old) rats. Leptin mRNA level was much higher in the old animals, whereas in contrast, old rats displayed much lower mRNA levels of SREBP-1c and lipogenic enzymes. Moreover, experimentally increased plasma leptin concentration in young rats to the value observed in old rats resulted in the decrease of SREBP-1c, FAS, and ACC mRNA levels in WAT. Thus, the increase of lep gene expression could, in part, account for the reduced SREBP-1c gene expression and, consequently, the diminished lipogenic activity in WAT of old animals.

Acetyl-CoA Carboxylase↗

PubMed2005

Mechanisms of enhanced carbohydrate and lipid metabolism in adipose tissue in uremia.

OBJECTIVE: Hyperlipidemia is a permanent finding in advanced renal failure. It is supposed to be responsible for the accelerated arteriosclerosis and cardiovascular complications observed in patients with that disease. The background is partially determined, however, our knowledge in this matter is not yet satisfactory. METHODS: This study is based on the experimental rat model of chronic renal failure (CRF). Considering white adipose tissue (WAT) lipogenesis upregulation in CRF, along with the determination of acetyl coenzyme A carboxylase (ACC) and fatty acid synthase (FAS) genes expression, we have measured WAT gene expression for sterol regulatory binding protein 1 (SREBP-1) at the level of protein mass and mRNA abundance. Furthermore, we have determined glucose uptake, glucose-to-CO 2 conversion rate, and glucose translocator (GLUT-4) gene expression in WAT. RESULTS: Upregulation of both FAS and ACC gene expression was found in WAT of CRF rats. It was accompanied by WAT SREBP-1 gene overexpression. Moreover, we have observed the increased glucose uptake, glucose to CO 2 conversion rate, and GLUT-4 gene expression in WAT of CRF rats in comparison with controls. CONCLUSION: SREBP-1 gene overexpression may contribute to enhanced lipogenesis upregulation in WAT of CRF rats. It is not excluded that the increased WAT glucose metabolism activity is also induced by this mechanism, although there is no evidence currently to that end. We hypothesize that the increased WAT lipogenesis capacity could be a part of mechanism(s) leading to CRF-induced hyperlipidemia.

Acetyl-CoA Carboxylase↗

PubMed2005

Enhanced citrate synthase activity in human pancreatic cancer.

OBJECTIVES: Assuming that a high flux of carbohydrate is strictly connected with lipid synthesis in neoplastic cells, one can hypothesize that the activity of citrate synthase, which plays an important role in glucose to lipid conversion, is enhanced in pancreatic cancer. The aim of the present study was to verify this hypothesis. METHODS: The activity of citrate synthase (as well as lactate and glucose 6-phosphate dehydrogenases) was measured using tissue extract prepared from specimens (pancreatic cancer and control specimens taken from the adjacent pancreatic normal tissue) obtained from 24 patients with ductal carcinoma who underwent pancreatoduodenectomy or total pancreatomy. RESULTS: The average of citrate synthase activity in human pancreatic ductal carcinoma is significantly higher comparing with adjacent nonneoplastic tissue: 40.2 +/- 27.2 and 18.3 +/- 13.6 nmole/min/mg protein, respectively (P = 0.001). The lactate dehydrogenase and glucose 6-phosphate dehydrogenase activity in human pancreatic ductal carcinoma were also higher than in adjacent nonneoplastic tissues. CONCLUSION: It is likely that enhanced citrate synthase activity contributes to the conversion of glucose to lipids in pancreatic cancer providing substrate for membrane lipids synthesis.

Adult↗

PubMed2004

Diversity of SREBP-1 gene expression in rat adipose tissue depots in response to refeeding after food restriction.

The SREBP-1c mRNA level and precursor (microsomal) form of SREBP-1 abundance were significantly higher in epididymal and perirenal than in subcutaneous white adipose tissue of control rats. Moreover, the SREBP-1c mRNA level and an amount of precursor form of SREBP-1 were significantly higher in the epididymal and perirenal white adipose tissue of rats maintained on restricted diet and refed ad libitum for 48 h as compared to the control animals. No significant effects of food restriction/refeeding on SREBP-1c mRNA level and an amount of precursor form of SREBP-1 were found in subcutaneous white adipose tissue. The mature (nuclear) form of SREBP-1 was significantly increased in the epididymal, perirenal and subcutaneous white adipose tissue of the food restricted/refed animals. The activity, protein level and the mRNA abundance of malic enzyme (one of the target genes for SREBP-1) increased significantly in the epididymal, perirenal and subcutaneous white adipose tissue of the food restricted/refed rats as compared to the control animals, however the increase in perirenal and epididymal was higher than in the subcutaneous white adipose tissue. The results presented suggest that SREBP-1c is differently expressed in various rat white adipose tissue depots both under basal (control) and dieting conditions.

Adipose Tissue↗

PubMed2004

Potential role of high serum leptin concentration in age-related decrease of fatty acid synthase gene expression in rat white adipose tissue.

Ageing in rats is associated with significant reduction of lipogenic enzymes genes expression and the rate of fatty acids synthesis in white adipose tissue. Since resistance to insulin and/or triiodothyronine is not directly related to reduction in lipogenic enzymes activity in white adipose tissue of old rats, we have proposed recently that the age-related increase in leptin gene expression and high serum leptin concentration could, at least partly, account for the down regulation of lipogenic enzymes gene expression. To test this hypothesis, in this paper we experimentally (by single intraperitoneal injection of recombinant leptin) increased plasma leptin concentration in young rats to the level observed in old animals, and we examined its effect on fatty acids synthase (FAS) gene expression in white adipose tissue. The results presented in this paper indicate that leptin administration to young rats, in amount that cause the increase in serum leptin concentration to that found in old rats, significantly decreased the white adipose tissue FAS gene expression. We propose, therefore, that leptin could play a causative role in the down-regulation of lipogenic enzyme gene expression observed with ageing.

Adipose Tissue↗

PubMed2004

Upregulation of lipogenic enzymes genes expression in white adipose tissue of rats with chronic renal failure is associated with higher level of sterol regulatory element binding protein-1.

Chronic renal failure (CRF) frequently results in hypertriglyceridemia and elevated plasma concentration of very-low-density lipoprotein (VLDL). These abnormalities are thought to be primarily due to depressed lipoprotein lipase and hepatic lipase activities, as well as impaired clearance of plasma lipoproteins. Some results suggest that not only lipoproteins catabolism but also their overproduction might contribute to hypertriglyceridemia in CRF. Because sterol regulatory element binding protein (SREBP) plays an important role in the regulation of lipid homeostasis, increased level of this transcription factor might be involved in modulating lipid metabolism in CRF. The purpose of the present study is to determine whether there is an altered regulation of the SREBP-1 in CRF rats and whether the altered regulation of SREBP-1 is associated with the upregulation of lipogenic enzymes genes expression in CRF rats. In the white adipose tissue (WAT) of CRF rats, marked increases in the microsomal (precursor) and nuclear (mature) forms of SREBP-1 have been found. The increase in SREBP-1 was associated with an increased level of lipogenic enzymes (acetyl-coenzyme A [CoA] carboxylase [ACC], adenosine triphosphate-citrate lyase [ACL], fatty acid synthase [FAS], glucose 6-phosphate dehydrogenase [G6PDH], 6-phosphogluconate dehydrogenase [6PGDH], and malic enzyme [ME]) genes expression. In turn, this was associated with an increased rate of fatty acids synthesis in WAT and a significant increase in plasma triacylglycerol (TAG) and VLDL concentration. Our study indicates that WAT SREBP-1 expression is increased in CRF rats and that SREBP-1 may play an important role in the increased fatty acid synthesis. These results reveal another facet of disturbed lipid metabolism in CRF.

Adipose Tissue↗

PubMed2004

Disturbances of purine nucleotide metabolism in uremia.

The increased concentration of adenosine triphosphate (ATP) in erythrocytes from patients with chronic renal failure (CRF) has been observed in many studies but the mechanism leading to these abnormalities still is controversial. It is believed that hyperphosphatemia and metabolic acidosis triggering enhanced reutilization of purine bases are the factors responsible for changes in erythrocyte nucleotide concentration. During the past decade we have performed several studies. A summary of the obtained results is presented. A high-performance liquid chromatography technique was used for the determination of plasma and intraerythrocyte nucleotide concentrations. Labeled adenine and adenosine were used for measuring adenine incorporation. In CRF patients treated conservatively increased concentrations of ATP levels and other nucleotides such as adenosine diphosphate were found. Adenosine monophosphate and hypoxanthine levels were lower than in controls. In hemodialyzed patients both ATP and adenosine monophosphate intraerythrocyte concentrations were higher than in controls. At the same time, adenosine monophosphate and hypoxantine level were comparable with levels in healthy people. The main pattern of nucleotides during hemodialysis remained unchanged, independent from the mode of therapy. The only exception was a decreased level of hypoxantine. Results of a consecutive study have suggested that the increased rate of adenine incorporation into the adenine nucleotide pool could be partially responsible for the increased ATP concentration in uremic erythrocytes. Last but not least, trying to elucidate the pathomechanism of adenine nucleotide disturbances in uremia, we have found that the concentration of N-methyl-2-pyridone-5-carboxamide (2PY), one of the end products of nicotinamide-adenine dinucleotide degradation, were enhanced in CRF patients to values that are potentially toxic. Our findings suggest that 2PY could be a novel uremic toxin. Disturbances of nucleotide metabolism are one of the important components of uremic syndrome.

Adenosine Triphosphate↗

PubMed2004

The age-related increase in N-methyl-2-pyridone-5-carboxamide (NAD catabolite) in human plasma.

N-Methyl-2-pyridone-5-carboxamide (2PY) is a major catabolite of NAD, which is excreted in the urine. Assay of plasma concentration and urine exrection of 2PY is of interest for monitoring niacin nutritional state and NAD catabolism. Aging has major impact on number of metabolic processes, but its effect on plasma and tissue 2PY concentration has not been studied so far. The present study was undertaken to investigate the effect of aging on human plasma 2PY concentration. Blood samples were collected from 78 (56 females and 22 males) healthy subjects at different age ranging from 5 to 90 years. Plasma ultrafiltrates were analyzed with liquid chromatography/mass spectrometry (LC/MS) for 2PY concentration. 2PY concentration was also evaluated in plasma and liver of young (2 month) and old (24 month) rats. The mean plasma 2PY concentration in young (5-16 years old) healthy subjects was 0.39 +/- 0.22 micromol/l while in old healthy subjects (50-90 years old) it was approximately 2.6-fold higher. No gender differences was found in plasma 2PY concentration. Univariate regression analysis displayed positive correlation between age and human plasma 2PY concentration (r = 0.57, p < 0.01) and between age and 2PY/creatinine ratio (r = 0.4, p < 0.01). Multivariate regression analysis indicates that both age and plasma creatinine concentrations were independently correlated with the increase in plasma 2PY concentration. Daily 2PY excretion with urine corrected for weight was approximately 30% lower in old subjects than in young humans. 2PY concentrations in liver and plasma of 2-month-old rats were lower than in 24-month-old rats. In conclusion, our results demonstrated that human plasma 2PY concentration increases with age. This could be a consequence of both decreased renal excretion and increased production in the the liver or other organs. Our results indicate that age should be taken into consideration in the interpretation of plasma 2PY concentration.

Adolescent↗

PubMed2004

BMI is the main determinant of the circulating leptin in women after vertical banded gastroplasty.

OBJECTIVE: To assess the main determinant of serum leptin concentration changes in morbidly obese patients treated by banded vertical gastroplasty. RESEARCH METHODS AND PROCEDURES: Serum leptin and insulin concentrations, insulin resistance, BMI, body weight, and body fat mass in 18 obese women and 8 obese men treated by vertical banded gastroplasty were studied. Lean women and men subjects were used as controls. RESULTS: Before surgery, serum leptin and insulin concentrations and insulin resistance index were significantly higher in morbidly obese patients than in control subjects. BMI, body fat mass, and serum triacylglycerol concentrations were also significantly higher in obese than in lean subjects. All of these parameters gradually decreased during 50 weeks after surgery. Univariate regression analysis displayed significant correlations between the following: serum leptin concentration and BMI (and body fat mass), serum leptin concentration and serum insulin concentration, and serum leptin concentration and insulin resistance index. Multivariate regression analysis indicated that only BMI was independently correlated with the decrease in serum leptin concentration. DISCUSSION: Obtained data suggest the following: 1) vertical banded gastroplasty causes reduction of body weight, serum leptin and insulin concentration, insulin resistance, and serum triacylglycerol concentration; and 2) BMI is the main determinant of the circulating leptin concentration in morbidly obese women after anti-obesity surgery.

Adult↗

PubMed2004

Tissue-specific effect of refeeding after short- and long-term caloric restriction on malic enzyme gene expression in rat tissues.

Restricting food intake to a level below that consumed voluntarily (85%, 70% and 50% of the ad libitum energy intake for 3 or 30 days) and re-feeding ad libitum for 48 h results in an increase of malic enzyme (ME) gene expression in rat white adipose tissue. The increase of ME gene expression was much more pronounced in rats maintained on restricted diet for 30 days than for 3 days. The changes in ME gene expression resembled the changes in the content of SREBP-1 in white adipose tissue. A similar increase of serum insulin concentration was observed in all groups at different degrees of caloric restriction and refed ad libitum for 48 h. Caloric restriction and refeeding caused on increase of ME activity also in brown adipose tissue (BAT) and liver. However, in liver a significant increase of ME activity was found only in rats maintained on the restricted diet for 30 days. No significant changes after caloric restriction and refeeding were found in heart, skeletal muscle, kidney cortex, and brain. These data indicate that the increase of ME gene expression after caloric restriction/refeeding occurs only in lipogenic tissues. Thus, one can conclude that caloric restriction/refeeding increases the enzymatic capacity for fatty acid biosynthesis.

Adipose Tissue↗

PubMed2003

The age-related inverse relationship between ob and lipogenic enzymes genes expression in rat white adipose tissue.

To determine whether increase of serum leptin (the known natural inhibitor of lipogenic enzymes gene expression) concentration would account for the age-related decrease in lipogenesis (a) serum leptin concentration; (b) leptin mRNA abundance; (c) the rate of fatty acid synthesis in vivo; (d) lipogenic enzymes activity and (e) mRNA levels were assayed in white adipose tissue (WAT) of male young and old rats. We found that leptin mRNA abundance in WAT and serum leptin concentration was much lower in young than in old animals. In contrast, the rate of fatty acid synthesis in WAT was much higher in young animals. The old rats displayed much lower lipogenic enzymes activities (acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), ATP-citrate lyase (ACL), malic enzyme (ME), glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase 6PGDH) and mRNA abundance as compared to young rats. Considering the inverse relationship between serum leptin concentration and lipogenic enzymes genes expression and known inhibitory effect of leptin on lipogenic enzymes gene expression, one can conclude that the increase of ob gene expression could at least partly account for the reduced WAT lipogenic enzymes genes expression in old animals.

ATP Citrate (pro-S)-Lyase↗