Biochemistry and molecular biology international, 1994
The recently published existence of a pool of amino acids absorbed onto the blood cell membranes ... more The recently published existence of a pool of amino acids absorbed onto the blood cell membranes in the rat has provided a new insight into the role of the blood cell amino acid pools, in the context of tissue-blood amino acid transport and their metabolic relationships. In the present study, this pool has been measured in a large (n = 40) representative healthy human population. This pool represents 9% of the blood cell amino acids, which is somewhat lower but in the same order as that previously measured in the rat. The inside-erythrocyte and plasma pools have also been quantified, giving an inside to outside ratio of 1.32 for the combined total amino acids. Statistically significant age related changes in the different blood compartments were detected for some amino acids (aspartate, asparagine, glutamine, tyrosine, methionine, phenylalanine, tryptophan and lysine) as well as for the ratio of tryptophan to the large neutral amino acids. The results obtained emphasize the importan...
Alanine metabolism in 24 hour starved 20-day pregnant rats, following intravenously administered ... more Alanine metabolism in 24 hour starved 20-day pregnant rats, following intravenously administered C14-alanine, in trace dose that does not affect the normal availability of this amino acid, has been studied. The steady state levels of alanine and glucose in blood, liver and skeletal muscle, together with the tissue glycogen, metabolites and amino acid composition pools, are given in both the maternal and foetal compartments compared with the virgin control rats. The utilization of alanine as a gluconeogenetic precursor is not increased in late pregnancy under 24-hour starvation and it depends on the lower blood substrate availability.
Medical Informatics and the Internet in Medicine, 2005
Statistics provides essential tool in Bioinformatics to interpret the results of a database searc... more Statistics provides essential tool in Bioinformatics to interpret the results of a database search or for the management of enormous amounts of information provided from genomics, proteomics and metabolomics. The goal of this project was the development of a software tool that would be as simple as possible to demonstrate the use of the Bioinformatics statistics. Computer Simulation Methods (CSMs) developed using Microsoft Excel were chosen for their broad range of applications, immediate and easy formula calculation, immediate testing and easy graphics representation, and of general use and acceptance by the scientific community. The result of these endeavours is a set of utilities which can be accessed from the following URL: http://gmein.uib.es/bioinformatica/statistics. When tested on students with previous coursework with traditional statistical teaching methods, the general opinion/overall consensus was that Web-based instruction had numerous advantages, but traditional methods with manual calculations were also needed for their theory and practice. Once having mastered the basic statistical formulas, Excel spreadsheets and graphics were shown to be very useful for trying many parameters in a rapid fashion without having to perform tedious calculations. CSMs will be of great importance for the formation of the students and professionals in the field of bioinformatics, and for upcoming applications of self-learning and continuous formation.
American Journal of Physiology-Endocrinology and Metabolism, 2005
Sex steroid hormones are important factors in the determination of fat distribution and accumulat... more Sex steroid hormones are important factors in the determination of fat distribution and accumulation. The aim of this study was to investigate the effect of testosterone (T), 17β-estradiol (17βE), and progesterone (P) on adrenergic receptor (AR) gene expression in 3T3-L1 preadipocytes and adipocytes and their relation to the proliferation and differentiation processes. Our data clearly show that α2A-AR was the highest AR subtype expressed in preadipocytes, whereas in mature adipocytes was by far β3-AR. In the differentiation process to adipocytes, α2A-AR expression was decreased to 0.3-fold ( P < 0.01), whereas β3-AR was upregulated 578-fold ( P < 0.001) compared with preadipocytes. In addition, the expression of α2A-AR in preadipocytes was increased upon incubation with T, 17βE, and P, and a stimulation of proliferation was also observed in 17βE- and P-treated cells. In mature adipocytes, 17βE and P enhanced both α2A- and β3-AR gene expression (although the effects on β3-AR m...
American Journal of Physiology-Cell Physiology, 2007
Caloric restriction (CR) without malnutrition has been shown to increase maximal life span and de... more Caloric restriction (CR) without malnutrition has been shown to increase maximal life span and delay the rate of aging in a wide range of species. It has been proposed that reduction in energy expenditure and oxidative damage may explain the life-extending effect of CR. Sex-related differences also have been shown to influence longevity and energy expenditure in many mammalian species. The aim of the present study was to determine the sex-related differences in rat liver mitochondrial machinery, bioenergetics, and oxidative balance in response to short-term CR. Mitochondria were isolated from 6-mo-old male and female Wistar rats fed ad libitum or subjected to 40% CR for 3 mo. Mitochondrial O2 consumption, activities of the oxidative phosphorylation system (complexes I, III, IV, and V), antioxidative activities [MnSOD, glutathione peroxidase (GPx)], mitochondrial DNA and protein content, mitochondrial H2O2 production, and markers of oxidative damage, as well as cytochrome C oxidase a...
The effects of starvation on the thermogenic parameters of three different mitochondrial subpopul... more The effects of starvation on the thermogenic parameters of three different mitochondrial subpopulations in brown adipose tissue (BAT) of both post-cafeteria obese and lean rats were investigated. Tissue from different BAT depots from fed and 24 h starved rats were collected, pooled and three mitochondrial subpopulations were isolated by differential centrifugation; the M1 fraction (1000 g), the M3 fraction (3000 g) and the M15 fraction (15,000 g). Thermogenic parameters were measured in the three mitochondrial subtypes, and uncoupling protein (UCP) mRNA was determined in BAT. The results showed that starvation induced a decrease in mitochondrial turnover in BAT from both lean and obese rats. Moreover, a selective net loss of UCP from the lightest mitochondrial fraction (M15) in lean rats, with a concomitant reduction of UCP mRNA was observed. The reductions did not occur in obese rats and, as a result, a change in UCP distribution between the mitochondrial subpopulations was produce...
American journal of physiology. Regulatory, integrative and comparative physiology, 2003
The objective of this study was to investigate the sex-dependent regulation of skeletal muscle un... more The objective of this study was to investigate the sex-dependent regulation of skeletal muscle uncoupling protein (UCP)3 mRNA expression in response to overweight and its relationship with serum levels of free fatty acids, leptin, and insulin. Two obesity models were used: rats made obese by feeding them with a cafeteria diet for 14 wk, and postcafeteria overweight rats fed a chow diet for 10 wk after consuming the cafeteria diet for 14 wk. The effects of 24-h fasting were studied in postcafeteria rats and their age-matched controls. The cafeteria rats ate a high-fat diet and attained an excess body weight that was higher in females (+59%) than in males (+39%). A trend to higher induction of abdominal muscle UCP3 mRNA in male rats than in females after cafeteria diet was apparent (+116% increase vs. +26% increase). Postcafeteria male but not female rats still showed the tendency to have increased UCP3 mRNA levels relative to their age-matched controls. A linear regression analysis s...
Pfl�gers Archiv European Journal of Physiology, 1999
Noradrenaline-dependent brown adipose tissue (BAT) thermogenesis is activated by the cold and exc... more Noradrenaline-dependent brown adipose tissue (BAT) thermogenesis is activated by the cold and excess energy intake, largely depends on the activity of the uncoupling protein 1 (UCP1), and is mediated mainly through the beta3-adrenoceptor (beta3-AR). We investigated the expression of ucp2, a gene that encodes a putative UCP1-like uncoupling protein, along with that of ucp1 and beta3-ar, in the interscapular BAT (IBAT) of male and female rats chronically fed a cafeteria diet. After 3 months on this diet, male rats attained a 34% excess body mass and showed IBAT hypertrophy and increased IBAT thermogenic potential, in terms of both UCP1 and UCP2 mRNA expression (both by 1.6-fold), UCP1 protein expression (by 1.75-fold) and GDP binding to IBAT mitochondria (by 2.2-fold); female rats attained a larger excess body weight (50%) and their IBAT, although hypertrophied, showed no signs of increased thermogenic potential per gram of tissue. Interestingly, the IBAT of female rats was already activated compared to males. Treatment of mouse brown adipocytes in primary culture with noradrenaline also triggered a dose-dependent increase of the levels of UCP1 mRNA and UCP2 mRNA. Retroregulatory down-regulation of the beta3-AR mRNA levels was found in the two models used. The results support a physiological role for UCP2, along with UCP1, in rodent BAT thermogenesis.
Biochemistry and molecular biology international, 1994
The recently published existence of a pool of amino acids absorbed onto the blood cell membranes ... more The recently published existence of a pool of amino acids absorbed onto the blood cell membranes in the rat has provided a new insight into the role of the blood cell amino acid pools, in the context of tissue-blood amino acid transport and their metabolic relationships. In the present study, this pool has been measured in a large (n = 40) representative healthy human population. This pool represents 9% of the blood cell amino acids, which is somewhat lower but in the same order as that previously measured in the rat. The inside-erythrocyte and plasma pools have also been quantified, giving an inside to outside ratio of 1.32 for the combined total amino acids. Statistically significant age related changes in the different blood compartments were detected for some amino acids (aspartate, asparagine, glutamine, tyrosine, methionine, phenylalanine, tryptophan and lysine) as well as for the ratio of tryptophan to the large neutral amino acids. The results obtained emphasize the importan...
Alanine metabolism in 24 hour starved 20-day pregnant rats, following intravenously administered ... more Alanine metabolism in 24 hour starved 20-day pregnant rats, following intravenously administered C14-alanine, in trace dose that does not affect the normal availability of this amino acid, has been studied. The steady state levels of alanine and glucose in blood, liver and skeletal muscle, together with the tissue glycogen, metabolites and amino acid composition pools, are given in both the maternal and foetal compartments compared with the virgin control rats. The utilization of alanine as a gluconeogenetic precursor is not increased in late pregnancy under 24-hour starvation and it depends on the lower blood substrate availability.
Medical Informatics and the Internet in Medicine, 2005
Statistics provides essential tool in Bioinformatics to interpret the results of a database searc... more Statistics provides essential tool in Bioinformatics to interpret the results of a database search or for the management of enormous amounts of information provided from genomics, proteomics and metabolomics. The goal of this project was the development of a software tool that would be as simple as possible to demonstrate the use of the Bioinformatics statistics. Computer Simulation Methods (CSMs) developed using Microsoft Excel were chosen for their broad range of applications, immediate and easy formula calculation, immediate testing and easy graphics representation, and of general use and acceptance by the scientific community. The result of these endeavours is a set of utilities which can be accessed from the following URL: http://gmein.uib.es/bioinformatica/statistics. When tested on students with previous coursework with traditional statistical teaching methods, the general opinion/overall consensus was that Web-based instruction had numerous advantages, but traditional methods with manual calculations were also needed for their theory and practice. Once having mastered the basic statistical formulas, Excel spreadsheets and graphics were shown to be very useful for trying many parameters in a rapid fashion without having to perform tedious calculations. CSMs will be of great importance for the formation of the students and professionals in the field of bioinformatics, and for upcoming applications of self-learning and continuous formation.
American Journal of Physiology-Endocrinology and Metabolism, 2005
Sex steroid hormones are important factors in the determination of fat distribution and accumulat... more Sex steroid hormones are important factors in the determination of fat distribution and accumulation. The aim of this study was to investigate the effect of testosterone (T), 17β-estradiol (17βE), and progesterone (P) on adrenergic receptor (AR) gene expression in 3T3-L1 preadipocytes and adipocytes and their relation to the proliferation and differentiation processes. Our data clearly show that α2A-AR was the highest AR subtype expressed in preadipocytes, whereas in mature adipocytes was by far β3-AR. In the differentiation process to adipocytes, α2A-AR expression was decreased to 0.3-fold ( P < 0.01), whereas β3-AR was upregulated 578-fold ( P < 0.001) compared with preadipocytes. In addition, the expression of α2A-AR in preadipocytes was increased upon incubation with T, 17βE, and P, and a stimulation of proliferation was also observed in 17βE- and P-treated cells. In mature adipocytes, 17βE and P enhanced both α2A- and β3-AR gene expression (although the effects on β3-AR m...
American Journal of Physiology-Cell Physiology, 2007
Caloric restriction (CR) without malnutrition has been shown to increase maximal life span and de... more Caloric restriction (CR) without malnutrition has been shown to increase maximal life span and delay the rate of aging in a wide range of species. It has been proposed that reduction in energy expenditure and oxidative damage may explain the life-extending effect of CR. Sex-related differences also have been shown to influence longevity and energy expenditure in many mammalian species. The aim of the present study was to determine the sex-related differences in rat liver mitochondrial machinery, bioenergetics, and oxidative balance in response to short-term CR. Mitochondria were isolated from 6-mo-old male and female Wistar rats fed ad libitum or subjected to 40% CR for 3 mo. Mitochondrial O2 consumption, activities of the oxidative phosphorylation system (complexes I, III, IV, and V), antioxidative activities [MnSOD, glutathione peroxidase (GPx)], mitochondrial DNA and protein content, mitochondrial H2O2 production, and markers of oxidative damage, as well as cytochrome C oxidase a...
The effects of starvation on the thermogenic parameters of three different mitochondrial subpopul... more The effects of starvation on the thermogenic parameters of three different mitochondrial subpopulations in brown adipose tissue (BAT) of both post-cafeteria obese and lean rats were investigated. Tissue from different BAT depots from fed and 24 h starved rats were collected, pooled and three mitochondrial subpopulations were isolated by differential centrifugation; the M1 fraction (1000 g), the M3 fraction (3000 g) and the M15 fraction (15,000 g). Thermogenic parameters were measured in the three mitochondrial subtypes, and uncoupling protein (UCP) mRNA was determined in BAT. The results showed that starvation induced a decrease in mitochondrial turnover in BAT from both lean and obese rats. Moreover, a selective net loss of UCP from the lightest mitochondrial fraction (M15) in lean rats, with a concomitant reduction of UCP mRNA was observed. The reductions did not occur in obese rats and, as a result, a change in UCP distribution between the mitochondrial subpopulations was produce...
American journal of physiology. Regulatory, integrative and comparative physiology, 2003
The objective of this study was to investigate the sex-dependent regulation of skeletal muscle un... more The objective of this study was to investigate the sex-dependent regulation of skeletal muscle uncoupling protein (UCP)3 mRNA expression in response to overweight and its relationship with serum levels of free fatty acids, leptin, and insulin. Two obesity models were used: rats made obese by feeding them with a cafeteria diet for 14 wk, and postcafeteria overweight rats fed a chow diet for 10 wk after consuming the cafeteria diet for 14 wk. The effects of 24-h fasting were studied in postcafeteria rats and their age-matched controls. The cafeteria rats ate a high-fat diet and attained an excess body weight that was higher in females (+59%) than in males (+39%). A trend to higher induction of abdominal muscle UCP3 mRNA in male rats than in females after cafeteria diet was apparent (+116% increase vs. +26% increase). Postcafeteria male but not female rats still showed the tendency to have increased UCP3 mRNA levels relative to their age-matched controls. A linear regression analysis s...
Pfl�gers Archiv European Journal of Physiology, 1999
Noradrenaline-dependent brown adipose tissue (BAT) thermogenesis is activated by the cold and exc... more Noradrenaline-dependent brown adipose tissue (BAT) thermogenesis is activated by the cold and excess energy intake, largely depends on the activity of the uncoupling protein 1 (UCP1), and is mediated mainly through the beta3-adrenoceptor (beta3-AR). We investigated the expression of ucp2, a gene that encodes a putative UCP1-like uncoupling protein, along with that of ucp1 and beta3-ar, in the interscapular BAT (IBAT) of male and female rats chronically fed a cafeteria diet. After 3 months on this diet, male rats attained a 34% excess body mass and showed IBAT hypertrophy and increased IBAT thermogenic potential, in terms of both UCP1 and UCP2 mRNA expression (both by 1.6-fold), UCP1 protein expression (by 1.75-fold) and GDP binding to IBAT mitochondria (by 2.2-fold); female rats attained a larger excess body weight (50%) and their IBAT, although hypertrophied, showed no signs of increased thermogenic potential per gram of tissue. Interestingly, the IBAT of female rats was already activated compared to males. Treatment of mouse brown adipocytes in primary culture with noradrenaline also triggered a dose-dependent increase of the levels of UCP1 mRNA and UCP2 mRNA. Retroregulatory down-regulation of the beta3-AR mRNA levels was found in the two models used. The results support a physiological role for UCP2, along with UCP1, in rodent BAT thermogenesis.
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