Effect of carbonyl compounds on red blood cells deformability

The AGE-RAGE Axis and the Pathophysiology of Multimorbidity in COPD

Chronic obstructive pulmonary disease (COPD) is a disease of the airways and lungs due to an enhanced inflammatory response, commonly caused by cigarette smoking. Patients with COPD are often multimorbid, as they commonly suffer from multiple chronic (inflammatory) conditions. This intensifies the burden of individual diseases, negatively affects quality of life, and complicates disease management. COPD and comorbidities share genetic and lifestyle-related risk factors and pathobiological mechanisms, including chronic inflammation and oxidative stress. The receptor for advanced glycation end products (RAGE) is an important driver of chronic inflammation. Advanced glycation end products (AGEs) are RAGE ligands that accumulate due to aging, inflammation, oxidative stress, and carbohydrate metabolism. AGEs cause further inflammation and oxidative stress through RAGE, but also through RAGE-independent mechanisms. This review describes the complexity of RAGE signaling and the causes of AGE accumulation, followed by a comprehensive overview of alterations reported on AGEs and RAGE in COPD and in important co-morbidities. Furthermore, it describes the mechanisms by which AGEs and RAGE contribute to the pathophysiology of individual disease conditions and how they execute crosstalk between organ systems. A section on therapeutic strategies that target AGEs and RAGE and could alleviate patients from multimorbid conditions using single therapeutics concludes this review.

Rheological Abnormalities in Human Erythrocytes Subjected to Oxidative Inflammation

Erythrocytes are oxygen carriers and exposed to redox cycle in oxygenation and deoxygenation of hemoglobin. This indicates that circulating erythrocytes are vulnerable to the oxidative injury occurring under the imbalance of redox homeostasis. In this review article, two topics are presented concerning the human erythrocytes exposed to the oxidative inflammation including septic and sterile conditions. First, we demonstrate rheological derangement of erythrocytes subjected to acute oxidative injury caused by exogenous generators of reactive oxygen species (ROS). Erythrocyte filterability as whole-cell deformability has been estimated by the gravity-based nickel mesh filtration technique in our laboratory and was dramatically impaired in a time-dependent manner after starting exposure to the ROS generators, that is associated with concurrent progression of membrane protein degradation, phospholipid peroxidation, erythrocyte swelling, methemoglobin formation, and oxidative hemolysis. Second, we introduce an impairment of erythrocyte filterability confirmed quantitatively in diabetes mellitus and hypertension of animal models and patients under treatment. Among the cell geometry, internal viscosity, and membrane property as the three major determinants of erythrocyte deformability, erythrocyte membrane alteration is supposed to be the primary cause of this impairment in these lifestyle-related diseases associated with persistent oxidative inflammation. Excessive ROS trigger the inflammatory responses and reduce the erythrocyte membrane fluidity. Oxidative inflammation increasing erythrocyte membrane rigidity underlies the impaired systemic microcirculation, which is observed in diabetic and/or hypertensive patients. On the other hand, elevated internal viscosity caused by sickle hemoglobin polymerization is a primary cause of impaired erythrocyte filterability in sickle cell disease (SCD). However, oxidative inflammation is also involved in the pathophysiology of SCD. The physiologic level of ROS acts as signaling molecules for adaptation to oxidative environment, but the pathological level of ROS induces suicidal erythrocyte death (eryptosis). These findings provide further insight into the ROS-related pathophysiology of many clinical conditions.

Carbonyl Stress in Red Blood Cells and Hemoglobin

The paper overviews the peculiarities of carbonyl stress in nucleus-free mammal red blood cells (RBCs). Some functional features of RBCs make them exceptionally susceptible to reactive carbonyl compounds (RCC) from both blood plasma and the intracellular environment. In the first case, these compounds arise from the increased concentrations of glucose or ketone bodies in blood plasma, and in the second-from a misbalance in the glycolysis regulation. RBCs are normally exposed to RCC-methylglyoxal (MG), triglycerides-in blood plasma of diabetes patients. MG modifies lipoproteins and membrane proteins of RBCs and endothelial cells both on its own and with reactive oxygen species (ROS). Together, these phenomena may lead to arterial hypertension, atherosclerosis, hemolytic anemia, vascular occlusion, local ischemia, and hypercoagulation phenotype formation. ROS, reactive nitrogen species (RNS), and RCC might also damage hemoglobin (Hb), the most common protein in the RBC cytoplasm. It was Hb with which non-enzymatic glycation was first shown in living systems under physiological conditions. Glycated HbA1c is used as a very reliable and useful diagnostic marker. Studying the impacts of MG, ROS, and RNS on the physiological state of RBCs and Hb is of undisputed importance for basic and applied science.

Impaired deformability and association with density distribution of erythrocytes in patients with type 2 diabetes mellitus under treatment

BACKGROUND

Disturbed microcirculation is related to diabetic complications, and erythrocyte deformability is a critical factor regulating microcirculation.

OBJECTIVES

To know the relationship between the impaired deformability and density profile in diabetic erythrocytes.

METHODS

We recruited patients with type 2 diabetes (n = 15, diabetic group) and age- and sex-matched non-diabetic subjects (n = 15, control group). Erythrocyte density (ED) profile was obtained by the phthalate ester separation technique. ED distribution was fitted by sigmoidal curve, yielding specific gravity of phthalate ester allowing passage of half erythrocytes population (ED50) and slope factor. Erythrocyte deformability was estimated by our specific filtration technique.

RESULTS

Diabetic group showed significantly (p < 0.001) higher HbA1c and fasting blood glucose concentration. Erythrocyte deformability in diabetic group was impaired as compared with that in control group (p < 0.001) and proportional to HbA1c (p = 0.009). However, ED50 and the slope factor in diabetic group did not differ from respective parameters in control group.

CONCLUSIONS

This study demonstrated that erythrocyte deformability was impaired in diabetic patients even under treatment. HbA1c up to 7.5% is concluded not to alter the erythrocyte density but to impair the deformability, which might be a warning to clinicians for prevention of diabetic complications.

Prognostic significance of red cell distribution width in hospitalized older patients with heart failure or infection

AIM

Red cell distribution width (RDW) is a simple, sensitive and cost-effective parameter, and is associated with pathophysiology of many common diseases. The aim of the present study was to investigate the prognostic role of RDW in older adults hospitalized for the treatment of heart failure (HF) or infection, because both diseases are fatal, especially in the geriatric population.

METHODS

This observational study consecutively enrolled 196 Japanese older (aged ≥75 years) patients hospitalized for the treatment of HF (group A, n = 102) or non-cardiovascular bacterial infection (group B, n = 94). Baseline and clinical data were extracted from medical records. The observational period was that of hospitalization. The primary end-point was classified in the order of discharge to the patients' home, discharge to other facilities and in-hospital death.

RESULTS

Longer hospital stay (P < 0.01) and worse prognosis (P < 0.01), including higher in-hospital mortality, were found in patients showing RDW ≥15% relative to those with RDW <15% in both groups. RDW showed no in-hospital variation despite successful treatment of acutely decompensated HF in selected patients of group A (n = 64).

CONCLUSIONS

The present study showed the role of RDW in predicting the prognostic outcome of older adults hospitalized for the treatment of HF or infection, indicating that RDW is a stable and reliable parameter in these common diseases. Geriatr Gerontol Int 2019; 19: 988-992.

Diabetes mellitus increases the prevalence of anemia in patients with chronic kidney disease: A nested case-control study

AIM: To compare anemia prevalence between matched chronic kidney disease (CKD) patients with and without diabetes mellitus (DM) and to assess factors associated with anemia development.

METHODS: This is a nested case-control study of 184 type-2 diabetic and 184 non-diabetic CKD patients from a prospectively assembled database of a Nephrology outpatient clinic, matched for gender, age and estimated glomerular filtration rate (eGFR). Prevalence of anemia (hemoglobin: Men: < 13 g/dL, women: < 12 g/dL and/or use of recombinant erythropoietin) was examined in comparison, in the total population and by CKD Stage. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with anemia.

RESULTS: The total prevalence of anemia was higher in diabetics (47.8% vs 33.2%, P = 0.004). Accordingly, prevalence was higher in diabetics in CKD Stage 3 (53.5% vs 33.1%, P < 0.001) and particularly in Stage 3a (60.4% vs 26.4%, P < 0.001), whereas it was non-significantly higher in Stage 4 (61.3% vs 48.4%; P = 0.307). Serum ferritin was higher in diabetics in total and in CKD stages, while serum iron was similar between groups. In multivariate analyses, DM (OR = 2.206, 95%CI: 1.196-4.069), CKD Stages 3a, 3b, 4 (Stage 4: OR = 12.169, 95%CI: 3.783-39.147) and serum iron (OR = 0.976, 95%CI: 0.968-0.985 per mg/dL increase) were independently associated with anemia.

CONCLUSION: Prevalence of anemia progressively increases with advancing stages of CKD and is higher in diabetic than matched non-diabetic CKD patients and diabetes is independently associated with anemia occurrence. Detection and treatment of anemia in diabetic CKD patients should be performed earlier than non-diabetic counterparts.

Impaired deformability of circulating erythrocytes obtained from nondiabetic hypertensive patients: investigation by a nickel mesh filtration technique

Introduction

Hypertension is associated with microcirculatory disturbance, and erythrocyte deformability is a major determinant of the microcirculation. However, impairment of erythrocyte deformability in hypertensive patients in relation to antihypertensive treatment is unclear. The present study aimed to investigate this impairment in hypertensive patients under treatment using a highly sensitive and quantitative nickel mesh filtration technique.

Methods

Deformability was evaluated by filterability, defined as the flow rate of a hematocrit-adjusted erythrocyte suspension relative to that of saline under a specific filtration pressure in a pressure-flow curve obtained by continuous filtration. Baseline characteristics of hypertensive patients (n = 101) and age-matched normotensive subjects (n = 14) were obtained from medical records, and diabetic patients were excluded.

Results

Erythrocyte deformability in the hypertensive group was significantly (p = 0.010) lower (87.8 ± 2.2 %) than that of the normotensive group (89.4 ± 1.7 %) and inversely proportional (r = −0.303, p = 0.002) to the mean blood pressure (BP) measured on blood sampling for the filtration study. Stepwise multiple regression analysis demonstrated that this impairment was mostly attributable to the mean BP (p = 0.001), whereas current smoking and episodes of stroke or coronary artery disease were not contributors.

Discussion

These findings indicate that erythrocyte deformability is impaired in the hypertensive patients, which depends on the current BP control rather than target organ damage.

[Hematopoietic stem cell exhaustion and advanced glycation end-products in the unexplained anemia of the elderly]

INTRODUCTION

More than 10% of the aged 65 years and over in the western world suffers anemia and in one third of them the cause of the anemia remains obscure. The unexplained anemia of the elderly (UAE) is considered an exclusion diagnosis, without the existence of a clear consensus to its clinical or experimental approach. There is an association between aging and anemia in studies performed in animals and in humans.

OBJECTIVES

To determine if there is evidence in the literature that supports hematopoietic stem cells (HSC) exhaustion and the advanced glycation end-products (AGE's) as a cause of UAE.

METHOD

A total of 32 combined texts (28 for HSC exhaustion and 4 for AGEs) were selected after an intensive review. Conclusions were associated with causes and effects of the HSC exhaustion and circulating AGE's over aging and anemia.

RESULTS

Only three works try to establish an association between UAE and HSC exhaustion, two of them disagreed in their conclusions, with the third one differing in the type of study. There is a relationship between anemia and AGEs increase and accumulation.

CONCLUSIONS

There is evidence in the literature that links the aging molecular and cellular mechanisms with the HSC exhaustion and the increase of AGE's. Furthermore; there is some evidence that both conditions determine the emergence of anemia associated with age in animals and in humans. There is little evidence in the literature to clarify the relationship between aging and UAE.

sRAGE is associated with low waist circumference and Hb levels in NAFLD

Advanced glycation end products (AGEs) and the receptor RAGE interaction is involved in nonalcoholic fatty liver disease (NAFLD). Although exogenously administered soluble RAGE (sRAGE) has been shown to block the harmful effects of AGEs in animal models, there is still controversy about the role of sRAGE in humans. We examined here which anthropometric, metabolic and clinical variables were independent correlates of sRAGE levels in NAFLD patients. The study involved 77 biopsy-proven, unmedictaed NAFLD patients (44 male and 33 female) with a mean age of 43.4±13.0 years old. We examined which anthropometric, metabolic and clinical variables, including liver steatosis and fibrosis markers, are independently associated with serum levels of sRAGE. Mean serum levels of sRAGE were 710.7±290.2 pg/mL. Univariate analysis revealed that waist circumference (inversely), hemoglobin (inversely), number of white blood cells (inversely), total-bilirubin (inversely), free fatty acid (inversely), ferritin (inversely), and HbA1c (inversely) were significantly correlated with serum levels of sRAGE. In multiple stepwise regression analysis, waist circumference (p<0.01, inversely) and hemoglobin (p<0.01, inversely) were independently associated with serum levels of sRAGE (R2=0.176). The present study reveals that low serum levels of sRAGE are independently associated with waist circumference and hemoglobin in patients with NAFLD.

Impaired Erythrocyte Deformability in Patients with Coronary Risk Factors: Significance of Nonvalvular Atrial Fibrillation

Although coronary risk factors promote the formation of atherosclerotic plaque containing activated platelets and inflammatory leukocytes, and play a pivotal role in the development of coronary artery diseases (CAD), the hemorheological effects of these risk factors on circulating intact erythrocytes, a major component of whole blood cells, are poorly understood. Therefore, this study aimed to quantify erythrocyte deformability in patients with coronary risk factors, and enrolled 320 consecutive cardiac outpatients including 33 patients with nonvalvular atrial fibrillation (AF). Patients with acute coronary syndrome or valvular AF were excluded. Demographic variables obtained by medical records were correlated with erythrocyte deformability investigated by our highly sensitive and reproducible filtration technique. Among demographic variables, triglyceride (p = 0.004), HbA1c (p = 0.014) and body weight (p = 0.020) showed significant inverse correlation to the erythrocyte deformability. This deformability was not associated with types of CAD (old myocardial infarction vs. stable angina) or modality of treatment (percutaneous intervention vs. coronary artery bypass grafting). Unexpectedly, stepwise multiple regression analysis demonstrated that nonvalvular AF was the most significant contributor to the impaired erythrocyte deformability (p = 0.002). Hypertension and dyslipidemia are more prevalent in the AF patients (p < 0.001), and the erythrocyte deformability was found to be impaired synergistically and significantly (p < 0.001) during the stepwise accumulation of the coronary risk factors in addition to AF. In conclusion coronary risk factors synergistically impair the erythrocyte deformability, which may play an important role in critically stenotic coronary arteries. Since the impairment of intact erythrocyte deformability is mostly associated with nonvalvular AF, this common arrhythmia may reflect the coronary risk accumulation.

Improvement of diabetic or obese patients' erythrocyte deformability by the program of the brain-oriented obesity control system (BOOCS)

Diabetes is characterized by absolute or relative insulin deficiency complicated with microangiopathy, whereas obesity stems from insulin resistance. A psychosomatic approach to obesity and diabetes has been highlighted, including the brain-oriented obesity control system (BOOCS). Impaired deformability of erythrocytes in obese or diabetic patients is closely linked to disturbed microcirculation, and improvement of abnormal erythrocyte rheology is a prerequisite for the prevention and treatment of microangiopathy. Therefore, erythrocyte filterability, whole cell deformability defined as flow rate of erythrocyte suspension relative to that of saline, was assessed by the nickel-mesh-filtration technique. Subjects included healthy controls (group A, n = 14), diabetic, non-obese participants (group B, n = 29), and non-diabetic, obese participants (group C, n = 32) in the 6-month BOOCS program, and most patients in groups B and C (86.9 %) completed this program. Baseline mean erythrocyte filterabilities were 89.4 ± 1.7 % in group A, 82.8 ± 5.2 % in group B, and 84.1 ± 5.6 % in group C, showing significant intergroup differences (p < 0.001). This program significantly improved (p < 0.001) the impaired erythrocyte filterability in groups B (87.9 ± 4.4 %) and C (88.5 ± 3.7 %). Declines in HbA1c (p = 0.387) and body mass index (p = 0.479) were not correlated to this improvement. These findings indicate that the mechanisms of BOOCS-induced improvement of diabetic or obese patients' erythrocyte deformability are multifactorial, and that the BOOCS program for these patients is a holistic, cost-effective, and highly compliant approach possibly ameliorating microcirculation.

Circulating selenium and carboxymethyl-lysine, an advanced glycation endproduct, are independent predictors of anemia in older community-dwelling adults

OBJECTIVE

To assess whether selenium and carboxymethyl-lysine (CML), two biomarkers of oxidative stress, are independent predictors of anemia in older community-dwelling adults.

METHODS

Plasma levels of selenium, CML, folate, vitamin B12, and testosterone and markers of iron status and inflammation were measured at baseline in 1036 adults at least 65 y old in the Invecchiare in Chianti Study, a population-based cohort study of aging in Tuscany, Italy, and examined in relation to prevalent anemia and incident anemia over 6 y of follow-up.

RESULTS

At enrollment, 11.6% of participants were anemic. Of 472 participants who were non-anemic at enrollment, 72 (15.3%) developed anemia within 6 y of follow-up. At enrollment, plasma CML in the highest quartile (>425 ng/mL) and plasma selenium in the lowest quartile (<66.6 μg/L) predicted incident anemia (hazard ratio 1.67, 95% confidence interval 1.07-2.59, P = 0.02; hazard ratio 1.55, 95% confidence interval 1.01-2.38, P = 0.05, respectively) in a multivariate Cox proportional hazards model that adjusted for age, education, body mass index, cognition, inflammation, red blood cell distribution width, ferritin, vitamin B12, testosterone, and chronic diseases.

CONCLUSION

Elevated plasma CML and low plasma selenium are long-term independent predictors of anemia in older community-dwelling adults. These findings support the idea that oxidative stress contributes to the development of anemia.

Skin autofluorescence and the association with renal and cardiovascular risk factors in chronic kidney disease stage 3

BACKGROUND AND OBJECTIVES

Tissue advanced glycation end products (AGE) accumulation is a measure of cumulative metabolic stress. Assessment of tissue AGE by skin autofluorescence (SAF) correlates well with cardiovascular (CV) outcomes in diabetic, transplant, and dialysis patients, and may be a useful marker of CV risk in earlier stages of chronic kidney disease (CKD).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

1707 patients with estimated GFR 59 to 30 ml/min per 1.73 m(2) were recruited from primary care practices for the Renal Risk In Derby (RRID) study. Detailed medical history was obtained, and each participant underwent clinical assessment as well as urine and serum biochemistry tests. SAF was assessed (mean of three readings) as a measure of skin AGE deposition using a cutaneous AF device (AGE Reader™, DiagnOptics, Groningen, The Netherlands).

RESULTS

Univariate analysis revealed significant correlations between AF readings and several potential risk factors for cardiovascular disease (CVD) and progression of CKD. SAF readings (arbitrary units) were also significantly higher among males (2.8 ± 0.7 versus 2.7 ± 0.6), diabetics (3.0 ± 0.7 versus 2.7 ± 0.6), patients with evidence of self-reported CVD (2.9 ± 0.7 versus 2.7 ± 0.6), and those with no formal educational qualifications (2.8 ± 0.6 versus 2.6 ± 0.6; P < 0.01 for all). Multivariable linear regression analysis identified hemoglobin, diabetes, age, and eGFR as the most significant independent determinants of higher SAF (standardized coefficients -0.16, 0.13, 0.12, and -0.10, respectively; R(2) = 0.17 for equation).

CONCLUSION

Increased SAF is independently associated with multiple CV and renal risk factors in CKD 3. Long-term follow-up will assess the value of SAF as a predictor of CV and renal risk in this population.

Does accumulation of advanced glycation end products contribute to the aging phenotype?

BACKGROUND

Aging is a complex multifactorial process characterized by accumulation of deleterious changes in cells and tissues, progressive deterioration of structural integrity and physiological function across multiple organ systems, and increased risk of death.

METHODS

We conducted a review of the scientific literature on the relationship of advanced glycation end products (AGEs) with aging. AGEs are a heterogeneous group of bioactive molecules that are formed by the nonenzymatic glycation of proteins, lipids, and nucleic acids.

RESULTS

Humans are exposed to AGEs produced in the body, especially in individuals with abnormal glucose metabolism, and AGEs ingested in foods. AGEs cause widespread damage to tissues through upregulation of inflammation and cross-linking of collagen and other proteins. AGEs have been shown to adversely affect virtually all cells, tissues, and organ systems. Recent epidemiological studies demonstrate that elevated circulating AGEs are associated with increased risk of developing many chronic diseases that disproportionally affect older individuals.

CONCLUSIONS

Based on these data, we propose that accumulation of AGEs accelerate the multisystem functional decline that occurs with aging, and therefore contribute to the aging phenotype. Exposure to AGEs can be reduced by restriction of dietary intake of AGEs and drug treatment with AGE inhibitors and AGE breakers. Modification of intake and circulating levels of AGEs may be a possible strategy to promote health in old age, especially because most Western foods are processed at high temperature and are rich in AGEs.

Advanced glycation endproducts and their receptor RAGE in Alzheimer's disease

Alzheimer's disease (AD) is the most common dementing disorder of late life. Although there might be various different triggering events in the early stages of the disease, they seem to converge on a few characteristic final pathways in the late stages, characterized by inflammation and neurodegeneration. In this review, we revisit the hypothesis that advanced glycation endproducts (AGEs) and their receptor RAGE may play an important role in disease pathogenesis. Accumulation of AGEs in cells and tissues is a normal feature of aging, but is accelerated in AD. In AD, AGEs can be detected in pathological deposits such as amyloid plaques and neurofibrillary tangles. AGEs explain many of the neuropathological and biochemical features of AD such as extensive protein crosslinking, glial induction of oxidative stress and neuronal cell death. Oxidative stress and AGEs initiate a positive feedback loop, where normal age-related changes develop into a pathophysiological cascade. RAGE and its decoy receptor soluble RAGE, may contribute to or protect against AD pathogenesis by influencing transport of β-amyloid into the brain or by manipulating inflammatory mechanisms. Targeted pharmacological interventions using AGE-inhibitors, RAGE-antagonists, RAGE-antibodies, soluble RAGE or RAGE signalling inhibitors such as membrane-permeable antioxidants may be promising therapeutic strategies to slow down the progression of AD.

Elevated serum advanced glycation end products and their circulating receptors are associated with anaemia in older community-dwelling women

OBJECTIVE

to determine whether serum carboxymethyl-lysine, a dominant advanced glycation end product (AGE), and circulating total receptor for AGEs (sRAGE) and endogenous secretory receptor for AGEs (esRAGE) are associated with anaemia.

DESIGN

cross-sectional analysis.

SETTING

moderately severely disabled women, > or =65 years, living in the community in Baltimore, MD (the Women's Health and Aging Study I).

PARTICIPANTS

519 women with and without anaemia.

MAIN OUTCOME MEASURE

haemoglobin and anaemia (haemoglobin <12 g/dL).

RESULTS

of 519 women, 128 (24.7%) had anaemia. All odds ratios (OR) were expressed per one standard deviation. Serum CML was associated with anaemia [OR 1.47, 95% confidence interval (CI) 1.11-1.95, P = 0.008] in a multivariate logistic regression model adjusting for age, race, smoking, education and chronic diseases. Serum sRAGE (ng/mL) and esRAGE (ng/mL) were associated with anaemia (OR 1.52, 95% CI 1.21-1.92, P = 0.0004; OR 1.49, 95% CI 1.18-1.87, P = 0.0006, respectively) in separate multivariate logistic regression models, adjusting for the same covariates mentioned above. Serum CML (P = 0.004), sRAGE (P < 0.0001) and esRAGE (P < 0.0001) were inversely and independently associated with haemoglobin concentrations.

CONCLUSION

AGEs and circulating RAGE are independently associated with haemoglobin and anaemia in older women. AGEs are amenable to interventions, as serum AGEs can be lowered by a change in dietary pattern and pharmacological treatment.

Heat Processing in Infant Formulas Induces Changes in Copper Tissue Levels in Suckling and Weanling Rats

AIM

To assess the effects of dehydration, conventional in-bottle sterilization, and ultrahigh-temperature (UHT) sterilization, involved in the production of infant formulas, on the copper bioavailability in rats at two stages.

METHODS

Two-week-old suckling rats were fed a reconstituted powder (P1) and an in-bottle-sterilized liquid infant formula (SC1) in a drinking bottle for 7 days. Weanling rats were fed P1, SC1, another powder (P2), and a liquid UHT formula (UHT2) complemented with a standard rat diet. Intake, body weight, and percentage copper absorption were calculated, and whole-body, serum, liver, skin, and erythrocyte copper concentrations were determined.

RESULTS

Food intake, body weight, and copper intake were reduced in suckling rats consuming SC1, but the percentage copper absorption increased, and whole-body and tissue copper concentrations were unaffected, except for the erythrocyte copper concentration which was significantly higher as compared with pups fed P1. In weanling rats, the only difference observed was the significantly higher liver copper concentration in animals fed the diet containing P1 as compared with the diets containing SC1 and UHT2.

CONCLUSIONS

Consuming the SC1 formula induced high erythrocyte copper levels in suckling rats, whereas the equivalent dehydrated formula (P1) induced elevated liver copper concentrations in weanling rats. This is associated with the different Maillard reaction products resulting from the processing of each infant formula and with the developmental stage of the animals.