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1.
Nutr Hosp ; 19(5): 300-4, 2004.
Article in Spanish | MEDLINE | ID: mdl-15516041

ABSTRACT

Starting the first 24 hours after burn injury, energy supply, antioxidants and polyamines were assessed in 25 severe burn patients (20 men and 5 women) with a mean age of 45.6 +/- 20.4 years. Nutritional assessment was performed at 7, 15 and 21 days and was compared with a control group (n = 30). In 21 patients the burned body surface area was 20%-50% and in four patients it was greater than 50%. A mean decrease in energy supply of approximately 40% versus the calculated theoretical value was found in the three periods: 1,186 +/- 32; 1,117 +/- 589 and 1,331 +/- 578 kcal. In the first 15 days antioxidant ingestion was slightly lower than the recommended daily allowance for vitamin C: 60 mg versus 57 +/- 32, 57 +/- 53 and 75 +/- 53 mg, and was lower during the entire period for vitamin E: 10 mg versus 5.0 +/- 2.9; 4.5 +/- 3.0 and 5.3 +/- 3.4 mg; selenium: 40 microg versus 22.8 +/- 13.7; 22.5 +/- 9.8 and 25.7 +/- 11.2 microg and zinc: 12 mg versus 7.3 +/- 3.0, 6.8 +/- 4.8 and 8.4 +/- 5.3 mg. Taurine ingestion decreased on day 15 and significantly increased on day 21: 65.7 +/- 30 mg, 50.9 +/- 25 and 72.0 +/- 29 mg (p < 0.05). Ingestion of total polyamines did not differ significantly from the values observed in the control group and were as follows: day 7, total 45.2 +/- 23.0 umol, putrescine 16.7 +/- 10.2, spermidine 13.5 +/- 7.6 and spermine 13.6 +/- 8.8; day 15: total 41.1 +/- 38.5 and 14.9 +/- 4.0, 11.7 +/- 9.4 and 10.89 +/- 9.0; day 21: total 39.1 +/- 35.3 and 15.4 +/- 16.9, 12.3 +/- 11.4 and 17.3 +/- 16.8 umol, respectively.


Subject(s)
Antioxidants/administration & dosage , Burns/metabolism , Polyamines/administration & dosage , Energy Intake , Female , Humans , Longitudinal Studies , Male , Middle Aged , Nutritional Status , Prospective Studies
2.
Nutr. hosp ; 19(5): 300-304, sept.-oct. 2004. tab
Article in Spanish | IBECS | ID: ibc-134959

ABSTRACT

El objetivo del estudio fue valorar el aporte energético, de antioxidantes y de poliaminas de la ingesta, iniciándose desde las primeras 24 horas inmediatas a la quemadura. La valoración nutricional se realizó a los 7, 15 y 21 días y se comparó con el grupo control (n = 30). La edad de los pacientes (n = 25; 20 hombres y 5 mujeres) fue de 45,6 ± 20,4 años. Veintiún pacientes presentaron una superficie corporal quemada (SQC) entre el 20-50% y en 4 casos fue superior al 50%. Se observó un descenso del aporte energético medio de ~40% vs el teórico calculado en los 3 períodos: 1.186 ± 32, 1.117 ± 589 y 1.331 ± 578 kcal. En los primeros 15 días la ingesta de antioxidantes fue ligeramente inferior a las RDA para la vitamina C: 60 mg vs 57 ± 32, 57 ± 53 y 75 ± 53 mg, e inferior durante todo el período para la vitamina E: 10 mg vs 5,0 ± 2,9; 4,5 ± 3,0 y 5,3 ± 3,4 mg, selenio: 40 µg vs 22,8 ± 13,7, 22,5 ± 9,8 y 25,7 ± 11,2 µg y zinc: 12 mg vs 7.3 ± 3.0; 6,8 ± 4,8 y 8.4 ± 5,3 mg. La ingesta de taurina descendió en el día 15 y se incrementó significativamente en el día 21: 65,7 ± 30 mg, 50,9 ± 25 y 72,0 ± 29 mg (p < 0,05). La ingesta de poliaminas totales no difirió significativamente de los valores hallados en el grupo control y fue el día 7, 45,2 ± 23,0 µmol, putrescina 16,7 ± 10,2, espermidina 13,5 ± 7,6 y espermina 13,6 ± 8,8; día 15: total 41,1 ± 38,5 y 14,9 ± 14,0, 11,7 ± 9,4 y 10,8 ± 9,0; el día 21: total 39,1 ± 35,3 y 15,4 ± 16,9, 12,3 ± 11,4 y 17,3 ± 16,8 µmol respectivamente (AU)


Starting the first 24 hours after burn injury, energy supply, antioxidants and polyamines were assessed in 25 severe burn patients (20 men and 5 women) with a mean age of 45.6 ± 20.4 years. Nutritional assessment was performed at 7, 15 and 21 days and was compared with a control group (n = 30). In 21 patients the burned body surface area was 20%-50% and in four patients it was greater than 50%. A mean decrease in energy supply of ~40% versus the calculated theoretical value was found in the three periods: 1,186 ± 32; 1,117 ± 589 and 1,331 ± 578 kcal. In the first 15 days antioxidant ingestion was slightly lower than the recommended daily allowance for vitamin C: 60 mg versus 57 ± 32, 57 ± 53 and 75 ± 53 mg, and was lower during the entire period for vita-min E: 10 mg versus 5.0 ± 2.9; 4.5 ± 3.0 and 5.3 ± 3.4 mg; selenium: 40 µg versus 22.8 ± 13.7; 22.5 ± 9.8 and 25.7 ± 11.2 µg and zinc: 12 mg versus 7.3 ± 3.0, 6.8 ± 4.8 and 8.4 ± 5.3 mg. Taurine ingestion decreased on day 15 and significantly increased on day 21: 65.7 ± 30 mg, 50.9 ± 25 and 72.0 ± 29 mg (p < 0.05). Ingestion of total polyamines did not differ significantly from the values observed in the control group and were as follows: day 7, total 45.2 ± 23.0 umol, putrescine 16.7 ± 10.2, spermidine 13.5 ± 7.6 and spermine 13.6 ± 8.8; day 15: total 41.1 ± 38.5 and 14.9 ± 4.0, 11.7 ± 9.4 and 10.89 ± 9.0; day 21: total 39.1 ± 35.3 and 15.4 ± 16.9, 12.3 ± 11.4 and 17.3 ± 16.8 umol, respectively (AU)


Subject(s)
Humans , Burns/diet therapy , Polyamines/administration & dosage , Antioxidants/administration & dosage , Micronutrients/administration & dosage , Energy Intake , Case-Control Studies , Treatment Outcome
3.
Nutr Hosp ; 18(4): 194-8, 2003.
Article in English | MEDLINE | ID: mdl-12884475

ABSTRACT

The aim of the study is to validate a cell culture model appropriate for assessing the effects of standard nutritional formulas on neutrophil functionality in vitro. The model consists of aged cells exposed to a commercial nutritional formula containing solely LCT as lipid component. Preliminary experiments determined dosage of formula and culture interval. Neutrophils were isolated from a pool of whole blood in healthy volunteers (18-55 years old) and cultured with and without addition of a commercial enteral diet with 3.5% lipids (equivalent to 0.04, 0.08, 0.2 and 0.4 mM of intraassay LCT) for 18, 42 or 76 hours. Based on cell viability results, doses of 0.2 and 0.4 mM LCT and culture time of 18 hours were established for subsequent experiments. Neutrophil functionality was evaluated by phagocytosis (NBT test), MDA production (lipoperoxidation index) and DNA fragmentation. Optic microscopy showed higher percentages of pre-apoptotic cells and a significant increase in DNA fragmentation as compared to controls only with an LCT concentration of 0.4 mM (p < 0.05). Interestingly, cell cultures with both 0.2 and 0.4 mM of added LCT showed significant decreases in malonyldialdehyde (MDA) release as a lipoperoxidation marker. This nutrition model of neutrophils and in vitro complete enteral commercial diet is relatively simply to execute and can be applied to different pathological conditions in which the aim is to study changes in neutrophil functionality.


Subject(s)
Enteral Nutrition , Neutrophils/physiology , Nutritional Physiological Phenomena/physiology , Adolescent , Adult , Biomarkers , Cell Survival , Cells, Cultured , Diet , Diphenylamine , Humans , In Vitro Techniques , Malondialdehyde/blood , Middle Aged , Models, Biological , Phagocytosis/physiology
4.
Nutr. hosp ; 18(4): 194-198, jul. 2003. tab
Article in En | IBECS | ID: ibc-24640

ABSTRACT

The aim of the study is to validate a cell culture model appropriate for assessing the effects of standard nutritional formulas on neutrophil functionality in vitro. The model consists of aged cells exposed to a commercial nutritional formula containing solely LCT as lipid component. Preliminary experiments determined dosage of formula and culture interval. Neutrophils were isolated from a pool of whole blood in healthy volunteers (18-55 years old) and cultured with and without addition of a commercial enteral diet with 3.5% lipids (equivalent to 0.04, 0.08, 0.2 and 0.4 mM of intraassay LCT) for 18, 42 or 76 hours. Based on cell viability results, doses of 0.2 and 0.4 mM LCT and culture time of 18 hours were established for subsequent experiments. Neutrophil functionality was evaluated by phagocytosis (NBT test), MDA production (lipoperoxidation index) and DNA fragmentation. Optic microscopy showed higher percentages of pre-apoptotic cells and a significant increase in DNA fragmentation as compared to controls only with an LCT concentration of 0.4 mM (p < 0.05). Interestingly, cell cultures with both 0.2 and 0.4 mM of added LCT showed significant decreases in malonyldialdehyde (MDA) release as a lipoperoxidation marker. This nutrition model of neutrophils and in vitro complete enteral commercial diet is relatively simply to execute and can be applied to different pathological conditions in which the aim is to study changes in neutrophil functionality (AU)


El objetivo del estudio ha sido validar un modelo en cultivo celular, apropiado para valorar los efectos in vitro de las fórmulas estándar y completas de nutrición enteral en la funcionalidad de los neutrófilos. El modelo consiste en células envejecidas a las que se añade una fórmula comercial de nutrición enteral que contiene LCT como fuente de lípidos. En experimentos preliminares se determinó la dosis de la fórmula y el intervalo de tiempo del cultivo. Los neutrófilos se aislaron a partir de un pool de sangre procedente de sujetos voluntarios sanos (18 a 55 años) y fueron cultivados sin y con la adición de la fórmula comercial enteral que contiene un 3,5 por ciento de lípidos con una concentración intraensayo equivalente a 0,04, 0,08, 0,2 y 0,4 mM de LCT durante 18, 42 o 76 horas. En base a los resultados de viabilidad celular obtenidos se establecieron como adecuados unas concentraciones de 0,2, 0,4 mM y un tiempo de cultivo de 18 horas en posteriores experimentos. La funcionalidad de los neutrófilos se evaluó mediante la fagocitosis (test del NBT), producción de malonildialdehído (MDA) como índice de lipoperoxidación y la fragmentación del ADN.Por microscopia óptica se observó que la adición de una dosis 0,4 mM de LCT (p < 0,05) producía porcentajes elevados de células preapoptóticas y un incremento significativo en la fragmentación del ADN al comparar con los controles sin adición. En cambio, cultivos con adición de 0,2 y 0,4 mM de LCT mostraron un descenso significativo en la producción de malonildialdehído. Este modelo de nutrición in vitro en neutrófilos y con una dieta comercial enteral completa es de relativamente fácil ejecución y puede aplicarse a diferentes condiciones patológicas en las que se estudien los cambios en la funcionalidad de los neutrófilos (AU)


Subject(s)
Middle Aged , Adult , Adolescent , Humans , Enteral Nutrition , Biomarkers , Models, Biological , Phagocytosis , Neutrophils , Cells, Cultured , Cell Survival , Diet , Diphenylamine , Malondialdehyde , Nutritional Physiological Phenomena
5.
Amino Acids ; 23(4): 441-5, 2002.
Article in English | MEDLINE | ID: mdl-12436213

ABSTRACT

This study determines the effects of taurine (Tau) on phagocytosis of polymorphonuclear neutrophils (PMN) isolated from normal subjects (n = 41) and severely burned patients (n = 20). Phagocytosis was measured by nitroblue of tetrazolium (NBT) reduction in samples with and without latex bead stimulation. Taurine was added at doses of 0.2, 0.4, 0.8 and 1.6 mM to stimulated samples. In control cells there were statistically significant increases in phagocytosis after addition of Tau 0.8 mM and 1.6 mM to as compared to samples without Tau addition (295 +/- 23% and 330 +/- 35% vs. 248 +/- 18%; mean +/- S.E.; p < 0.05). A statistically significant increase in phagocytosis was observed in cells from the burned population after addition of Tau 1.6 mM (288 +/- 38% vs. 198 +/- 13%; mean +/- S.E.; p < 0.05). No changes in phagocytosis were found in cells from a subgroup of burn patients (n = 13) followed over 7, 15 and 21 days. These results indicate that taurine supplementation in vitro at doses of 0.8 to 1.6 mM improves the phagocytic capacity of neutrophils in healthy subjects and in patients with severe burn injury, mainly when neutrophil function is unaltered.


Subject(s)
Burns/immunology , Neutrophils/immunology , Phagocytosis/drug effects , Taurine/pharmacology , Adult , Female , Humans , Male , Middle Aged , Neutrophils/drug effects , Statistics as Topic
6.
Nutrition ; 17(11-12): 934-8, 2001.
Article in English | MEDLINE | ID: mdl-11744344

ABSTRACT

OBJECTIVES: Putrescine, the precursor for higher polyamine biosynthesis, is necessary for cell growth in mammals. Ornithine decarboxylase (ODC) activity and polyamine production are increased in neoplastic cells. Using colon cancer cell line derived from a tumor with high metastatic potential (CT-26), our objective was to study the effect of exogenous putrescine on ODC regulation, polyamine metabolism, and cell proliferation. METHODS: Cells cultured with fetal calf serum were exposed to 100, 550, and 1000 microM putrescine for 24 h. RESULTS: Intracellular free putrescine, determined by high-performance liquid chromatography, showed a statistically significant increase in exposed cells compared with controls and a significant correlation with levels of the metabolite present in the medium (r = 0.93; P < 0.001). Bromodeoxyuridine incorporation into newly synthesized DNA, a marker of cell proliferation, showed a statistically significant increase in the three putrescine groups as opposed to the control group. In samples with added aminoguanidine, significant increases in DNA synthesis were observed in the 550- and 1000-microM putrescine groups as opposed to the control group. Spermidine and spermine intracellular contents in all three putrescine-treated groups remained below control levels. No statistical differences in ODC enzymatic activity or ODC mRNA content were observed. Newly incorporated putrescine stimulated colon tumor cell growth. CONCLUSIONS: Because neither enhanced conversion into the higher polyamines nor aminoguanidine inhibition of proliferation was observed, we suggest that this effect can be attributed to the putrescine molecule itself.


Subject(s)
Cell Division/drug effects , Ornithine Decarboxylase/metabolism , Putrescine/physiology , Adenocarcinoma , Cell Division/physiology , Chromatography, High Pressure Liquid , Colonic Neoplasms , Dose-Response Relationship, Drug , Humans , Polyamines/metabolism , Putrescine/pharmacology , Time Factors , Tumor Cells, Cultured
7.
Clin Nutr ; 20(2): 171-5, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11327746

ABSTRACT

The major consequence of extensive intestinal resection is loss of absorptive surface area, which results in malabsorption of nutrients; this condition is known as short-bowel syndrome (SBS). Patients with extensive small intestinal resection and colectomy leading to jejunostomy have the most severe SBS. Ornithine decarboxylase (ODC) plays a central role in cell proliferation and in the process of gut adaptation. Polyamine synthesis in crypt cells mediates the action of extracellular growth factors on DNA synthesis and mitotic activity. The aim of this study was to examine ODC expression and activity, diamine oxidase (DAO) activity and polyamine levels in the jejunal mucosa and red blood cells of SBS patients with a jejunostomy. The study group consisted of 6 patients (4 men and 2 women, mean age 55.8+/-9.8 years), who had undergone extensive small bowel resection and colectomy. All patients were maintained on cyclic parenteral nutrition and non-restricted oral nutrition. Two groups of patients operated on for unrelated reasons were included as the jejunum control group (n=6) and the ileum control group (n=13). Non statistical differences were observed in polyamine levels of red blood cells versus the control group (spermidine: 21.0+/-3.6 vs. 17.7+/-1.1 and spermine: 17.1+/-8.6 vs. 13.2+/-1.6 nmol/ml RBC, respectively). No significant decreases in putrescine and spermidine levels were observed between the groups, but spermine levels in SBS jejunum were significantly lower than the controls (P<0.05). In SBS patients a significant decrease in ODC and DAO activity were observed vs jejunum. A significant decrease in ODC-mRNA abundance was found for the SBS patients as compared to the two control groups (P<0.05). These results suggest that in SBS patients with jejunostomy intestinal adaptation may be impaired.


Subject(s)
Intestinal Absorption , Intestinal Mucosa/enzymology , Intestine, Small/surgery , Ornithine Decarboxylase/metabolism , Short Bowel Syndrome/enzymology , Adaptation, Biological , Adult , Aged , Amine Oxidase (Copper-Containing)/metabolism , Case-Control Studies , Cell Division , Colectomy , Female , Humans , Intestinal Mucosa/metabolism , Intestine, Small/enzymology , Intestine, Small/metabolism , Jejunostomy , Male , Middle Aged , Ornithine Decarboxylase/genetics , Parenteral Nutrition , Polyamines/metabolism , RNA, Messenger/metabolism , Short Bowel Syndrome/physiopathology
8.
Pathol Biol (Paris) ; 49(3): 227-31, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11367557

ABSTRACT

Total antioxidant capacity (TAC) was measured after severe burns (non-electric with one exception) in two groups of patients: group A, 24 subjects (19 men and five women) 20-67 years old and group B, eight subjects (six men and two women) 20-54 years old, admitted to the Major Burns Unit of hospital general Vall d'Hebron over a period of nine months. Albumin, uric acid and antioxidant capacity analyses were carried out within 24 hours after injury in both groups, and additionally at 1, 7, 15 and 21 days in group B. Total antioxidant capacity was measured by inhibition of blue-green colour of the ABTS+ cation (600 nm) and compared with reference values obtained in healthy, sex and age-matched volunteers (n = 50). Results showed statistically increased mean antioxidant capacity values at 24 hours (Group A: 1.36 +/- 0.22 mmol/L; Group B: 1.66 +/- 0.39) as compared with reference values (range, 1.0 to 1.44 mmol/L), representing 42% of patients in group A and 50% in group B (overall mean 46%), with no correlation with severity of the burn. The longitudinal study (Group B) showed no correlation between total antioxidant capacity values and time (r = -0.171; ns). A statistically significant correlation was found between albumin and time (r = 0.438; p < 0.05), indicating a clear tendency toward normalisation of plasma albumin values during healing. There was no correlation among total antioxidant capacity, percentage of burned surface and clinical evolution, suggesting a poor sensitivity of the method for the study of this pathology.


Subject(s)
Antioxidants/analysis , Burns/blood , Adult , Aged , Burn Units , Colorimetry , Female , Humans , Length of Stay , Longitudinal Studies , Male , Middle Aged , Oxidation-Reduction , Oxidative Stress , Serum Albumin/analysis , Severity of Illness Index , Uric Acid/blood
9.
Nutr Hosp ; 15(3): 85-91, 2000.
Article in Spanish | MEDLINE | ID: mdl-10920678

ABSTRACT

Polyamines are extremely important for cell growth, a fact that is reflected in the strict control of their synthesis and breakdown. In the small intestine, the polyamines play a fundamental role in all processes involving tissue regeneration, such as healing of stress-related ulcers, post-hepatectomy hepatic regeneration, adaptation syndrome after fasting and all processes with enterocyte hyperplasia or hypertrophy. In the gastrointestinal tract, there is a polyamine gradient in the villi-crypt cell axis and along the digestive tube, itself; the segments with greatest luminal content are the jejunum and the colon. Endogenous polyamine synthesis is stimulated by the diet and normal bacterial flora, which, in turn, regulate the amount and concentration of polyamines. Other hormonal and active peptide components (e.g. gastrin, epidermal growth factor, growth hormone) also have an influence on the pathway of polyamine synthesis. The interaction of these factors as related to the intestinal adaptive response is reviewed.


Subject(s)
Biogenic Polyamines/metabolism , Digestive System/metabolism , Animals , Biological Transport , Cell Division/physiology , Digestive System/cytology , Enterohepatic Circulation , Humans , Intestinal Mucosa/metabolism , Intestine, Small/cytology , Intestine, Small/metabolism
10.
Nutr. hosp ; 15(3): 85-91, mayo 2000.
Article in Es | IBECS | ID: ibc-13388

ABSTRACT

Las poliaminas son extraordinariamente importantes para el crecimiento celular, lo que se refleja en su estricto control a nivel de la regulación de su síntesis y degradación. En el intestino delgado juegan un. papel primordial en todos aquellos procesos en los que interviene la regeneración tisular tales como la curación de las úlceras de estrés, regeneración hepática poshepatectomía, lactancia, síndrome de adaptación después del ayuno o cualquiera que suponga hiperplasia o hipertrofia de los enterocitos. En el tracto gastrointestinal existe un gradiente en el eje villi-cripta y a lo largo del propio tubo digestivo, siendo las zonas con mayor contenido luminal el yeyuno y el colon. Los estímulos para su síntesis endógena son la dieta y la propia flora bacteriana que a su vez influyen en la cantidad y concentración de las poliaminas. Otros péptidos activos u hormonas que también pueden influir en la vía de síntesis de las poliaminas son, por ejemplo, la gastrina, el factor de crecimiento epidérmico o la hormona del crecimiento. Revisamos las interacciones de estos factores en la respuesta adaptatioa del intestino (AU)


Polyamines are extremely important for cell growth, a fact that is reflected in the strict control of their synthesis and breakdown. In the small intestine, the polyamines play a fundamental role in all processes involving tissue regeneration, such as healing of stress-related ulcers, posthepatectomy hepatic regeneration, adaptation syndrome after fasting and all processes with enterocyte hyperplasia or hypertrophy. In the gastrointestinal tract, there is a polyamine gradient in the villi-crypt cell axis and along the digestive tube, itself; the segments with greatest luminal content are the jejunum and the colon. Endogenous polyamine synthesis is stimulated by the diet and normal bacterial flora, which, in turn, regulate the amount and concentration of polyamines. Other hormonal and active peptide components (e.g. gastrin, epidermal growth factor, growth hormone) also have an influence on-the pathway of polyamine synthesis. The interaction of these factors as related to the intestinal adaptive response is reviewed (AU)


Subject(s)
Animals , Humans , Biogenic Polyamines , Biological Transport , Cell Division , Digestive System , Intestinal Mucosa , Intestine, Small , Enterohepatic Circulation
11.
J Appl Toxicol ; 20(1): 21-4, 2000.
Article in English | MEDLINE | ID: mdl-10641013

ABSTRACT

The effect of melatonin on inhibition of cell growth was studied in CT-26, a murine colon carcinoma-derived cell line. Cells growing in exponential phase were exposed to low (10(-7)-10(-10) M) and high doses (1, 2 and 3 x 10(-3) M) of melatonin during 24 h. Synthesis of DNA was measured by 5-bromo-2'-deoxyuridine incorporation. There was no effect at low doses, but a statistically significant correlation was found between the decrease in DNA synthesis and the dose of melatonin used (r = -0.52, P < 0.001). This implied the following percentages of inhibition: 1 mM, 22%; 2 mM, 25%; 3 mM, 47%. Potential cell membrane damage by high doses of melatonin was investigated by lactate dehydrogenase measurement and no significant levels were observed. Analysis with a single saturation technique showed no detectable oestradiol receptors in this cell type; therefore, we can assume that the effects occurring with the addition of melatonin were not mediated by modulation of this hormone on oestrogen receptors. The decreases in cell growth were attributed to a moderate, but significant antiproliferative action of melatonin on this non-hormone-dependent cell line.


Subject(s)
Adenocarcinoma/pathology , Colonic Neoplasms/pathology , DNA, Neoplasm/biosynthesis , Melatonin/pharmacology , Adenocarcinoma/metabolism , Animals , Cell Division/drug effects , Colonic Neoplasms/metabolism , Dose-Response Relationship, Drug , L-Lactate Dehydrogenase/metabolism , Mice , Receptors, Estradiol/metabolism , Tumor Cells, Cultured
12.
Nutr Hosp ; 14(3): 101-13, 1999.
Article in Spanish | MEDLINE | ID: mdl-10424123

ABSTRACT

The polyamines, putrescine, spermidine and spermine, are low-molecular weight substances, synthesized in eucariot cells from their immediate precursor, ornithine. These nitrogen compounds are essential for growth. The organism's endogenous supply is obtained through the diet or by synthesis in the intestinal flora. The polyamines are found in fruits and vegetables, foods of animal origin (milk, eggs, fish, and meat) and fermented food products (cheese, beer, and sauerkraut). Being nitrogenated compounds, they are considered as "minor" components of the diet. Ornithine decarboxylase, a short-half life enzyme, is the key to polyamine biosynthesis. Cellular polyamines are found in free or conjugated forms, the latter made possible, above all, by the presence of positive charges in their molecules. Their particular structure facilitates interaction with anions and binding to nuclear and membrane structures, particularly phospholipids, proteins and DNA. The organism's requirements for these substances are elevated during phases of intense growth or increased demand; thus, the nutritional supply can be crucial during the evolution of processes that involve a high degree of loss combined with deficits in endogenous biosynthesis. Increased tissue and organ polyamine concentrations correlate with diseases of neoplastic origin. It has been hypothesized that polyamine inhibition could be a therapeutic mechanism for such conditions. The supply of polyamines in artificial nutrition has not been measured and there are few data on the effects of artificial nutrition on circulating levels or the usual sites of storage in the body.


Subject(s)
Diet , Polyamines/metabolism , Humans , Nutritional Requirements
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