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H L Müller

Publications and source records attributed to H L Müller.

At least 37 records · Page 2Linked to original sources
PubMed1993

Demonstration of receptors for insulin-like growth factor binding protein-3 on Hs578T human breast cancer cells.

Hs578T human breast cancer cells are from an estrogen receptor-negative breast cell line derived from a highly aggressive mammary tumor. Our previous insulin-like growth factor binding protein-3 (IGFBP-3) binding studies (Oh, Y., Müller, H. L., Lamson, G., and Rosenfeld, R. G. (1993) J. Biol. Chem. 268, 14964-14971) have demonstrated specific binding of IGFBP-3 on the Hs578T cell surface and a significant inhibitory effect of IGFBP-3, itself, on monolayer growth. In this study, we have demonstrated cell surface association proteins that are specific for IGFBP-3 by showing: 1) detection of 20-, 26-, and 50-kDa proteins by affinity cross-linking with 125I-IGFBP-3E. coli and immunoprecipitation of cell monolayers and cell lysates with anti-IGFBP-3 antibodies; 2) dose-dependent competition of 125I-IGFBP-3E. coli by unlabeled IGFBP-3E. coli; 3) inhibition of IGFBP-3 binding to these cell surface proteins by EDTA and by coincubation with native insulin-like growth factor II (IGF-II), but not by coincubation with [Gln6,Ala7,Tyr18,Leu19,Leu27]IGF-II, an IGF-II analog with decreased affinity for IGFBP-3; and 4) partial purification of 20- and 26-kDa species by IGFBP-3.anti-IGFBP-3 antibody immunoaffinity membranes. Characteristics of these specific IGFBP-3 cell surface association proteins are identical to those observed in our previous monolayer binding assay and monolayer growth assay experiments. The specificity of binding and the inhibitory effect of IGFBP-3 binding on Hs578T cell growth suggest that these cell surface proteins are IGFBP-3-specific receptors or receptor subunits mediating the direct inhibitory effect of IGFBP-3 on monolayer growth of Hs578T cells.

Amino Acid Sequence↗
PubMed1993

Insulin-like growth factor (IGF)-independent action of IGF-binding protein-3 in Hs578T human breast cancer cells. Cell surface binding and growth inhibition.

Estrogen receptor-negative Hs578T human breast cancer cells secrete insulin-like growth factor binding protein (IGFBP)-3 and IGFBP-4 as major binding protein (BP) species. Our previous immunohistochemical studies (Oh, Y., Müller, H. L., Pham, H., Lamson, G., and Rosenfeld, R. G. (1992) Endocrinology 131, 3123-3125) have demonstrated the existence of cell surface-associated IGFBP-3 and release of cell surface-associated IGFBP-3 into conditioned media by addition of IGF peptide in Hs578T cells. In this study, we have demonstrated that IGFBP-3 binding on the cell surface is specific and receptor-mediated, by showing: 1) a dose-dependent increase of IGFBP-3 binding by addition of divalent cations (CaCl2 and MnCl2); 2) dose-dependent competition of 125I-IGFBP-3E. coli by unlabeled IGFBP-3E.coli (> 80% competition at 100 nM), but not by IGFBP-1 or fibronectin. In addition, exogenous IGFBP-3 treatment resulted in a significant inhibitory effect on monolayer growth of Hs578T cells. This inhibitory effect of IGFBP-3 was shown to be specific and IGF-independent by demonstrating: 1) dose-dependent inhibition on cell growth (60% inhibition at 20 nM) and inhibition on DNA synthesis (10 nM; p < 0.05, 20 nM; p < 0.005) by exogenous IGFBP-3E. coli, but not by IGFBP-1; 2) absence of stimulatory effects on monolayer cell growth by either native IGFs or IGF analogs which have significantly decreased affinity for IGFBPs, but retain full affinity for type 1 and 2 IGF receptors; 3) significant diminution of the IGFBP-3 inhibitory effects on monolayer growth by coincubation with native IGFs, but not by coincubation with IGF analogs with decreased affinity for IGFBP-3. In conclusion, exogenous IGFBP-3 shows specific binding on the cell surface and can inhibit Hs578T cell monolayer growth by itself, suggesting the existence of specific membrane-associated proteins or receptors for IGFBP-3. Furthermore, IGF-I and -II can attenuate inhibitory effect of IGFBP-3 by forming IGF.IGFBP-3 complexes, thereby preventing cell surface binding of IGFBP-3.

Amino Acid Sequence↗
PubMed1993

[The effect of palmitic, oleic and linoleic acids on thermogenesis in the model experiment in sows].

An animal model experiment was conducted with nine adult sows to study the effects of long-chain fatty acids on thermogenesis when different fatty acids were replaced for 30% of the energy of a basal diet based on cereals and soybean meal. The acids were fed as commercial products containing as main constituent either palmitic acid, oleic acid, or linoleic acid, according to a latin square design in experimental periods 2 to 4. In periods 1 and 5 the sows were submitted to basal diet alone. Digestibility of palmitic acid was only 36%, whereas the unsaturated fatty acids were highly absorbed (90%). Interaction effects of the undigested proportion of the long-chain fatty acids with the basal diet in hindgut fermentation could be ruled out since a supplementary experiment on three sows showed no influence of infusion of oleic or linoleic acid into the caecum on the energy utilization of the basal diet. There was no significant differences in thermogenesis among the fatty acids. Heat production in the treatment periods averaged -1.2% as compared to the basal diet periods. This result was in accordance with the value -1.0% calculated theoretically for the reduction in heat production in the treatment periods. Thus, the data did not indicate any stimulating effect of long-chain fatty acids on heat production, and utilization of energy of fatty acids occurred within the obligatory thermogenesis.

Absorption↗
PubMed1993

Characterization of the affinities of insulin-like growth factor (IGF)-binding proteins 1-4 for IGF-I, IGF-II, IGF-I/insulin hybrid, and IGF-I analogs.

Insulin-like growth factor (IGF)-binding proteins (BPs) bind IGF-I and IGF-II with high affinity and modify the activity of IGF peptides in a complex manner. We have characterized the affinities of IGFBP-1-4 for IGF-I and -II by employing 1) purified IGFBP preparations, 2) both [125I]IGF-I and [125I]IGF-II as radioligands, and 3) multiple IGF analogs designed to have altered affinities for IGFBPs. To this end, human (h) IGFBP-1, hIGFBP-2, and rat (r) IGFBP-4 have been purified to homogeneity from human amniotic fluid, human prostate epithelial cell culture, and B104 rat neuroblastoma cells; for human IGFBP-3, the glycosylated recombinant form (rec-hIGFBP-3), produced in Chinese hamster ovary cells, was employed. The IC50 values of IGF-I for hIGFBP-1, hIGFBP-2, rec-hIGFBP-3, rIGFBP-4, and human serum IGFBPs were 0.05 +/- 0.01, 5.0 +/- 0.01, 0.25 +/- 0.20, 0.6 +/- 0.4, and 0.1 +/- 0.01 ng/ml, respectively. While hIGFBP-1 and rIGFBP-4 had virtually equivalent affinities for IGF-I and IGF-II, hIGFBP-2 and rec-hIGFBP-3 demonstrated 2- to 5-fold higher affinities for IGF-II than for IGF-I. Studies with [Gln3,Ala4,Tyr15,Leu16]IGF-I and Des-(1-3)-IGF-I indicate that specific residues in the first 16 amino acids of the B domain of IGF-I appear to be critical for binding to all of the IGFBPs tested, but not to IGF receptors. However, severe modifications in the B domain disrupt binding affinity, not only for IGFBPs, but also for receptors (IGF-I/insulin hybrid and B-chain mutant). Interestingly, modifications in the A domain of IGF-I, which is believed to contain residues critical for binding to IGF-I and insulin receptors, show differential effects on binding affinity to BPs. [Thr49,Ser50,Ile51]IGF-I, which has normal affinity for the type I IGF receptor, shows at least a 500-fold decreased affinity for hIGFBP-1 and recombinant hIGFBP-3, in contrast to 50- to 100-fold reduced affinity for hIGFBP-2 and rIGFBP-4, and 5- to 10-fold reduced affinity for purified human serum IGFBP-3. More significantly, [1-27,Gly4,38-70]IGF-I shows a 30-fold decreased affinity for the type I IGF receptor and 10- and 2.5-fold reduced affinities for hIGFBP-1 and rec-hIGFBP-3, respectively, but no reduction in affinity for hIGFBP-2 or rIGFBP-4.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1993

Concentrations of insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3), IGF, and IGFBP-3 protease activity in cerebrospinal fluid of children with leukemia, central nervous system tumor, or meningitis.

Insulin-like growth factor-II (IGF-II) is the major IGF in human cerebrospinal fluid (CSF), whereas IGF-I is only detectable in trace amounts. The major IGFBPs in CSF are IGFBP-2 and IGFBP-4. Normally, IGFBP-3 is a minor component in CSF of healthy subjects, but may be increased in pathological states. We investigated IGF-I, IGF-II, and IGFBP-3 levels by specific RIAs in CSF from patients with central nervous system (CNS) tumor or leukemia and compared them with values in patients with meningitis. Further, as proteolysis of IGFBP-3 is part of the modulation of IGF activity, IGFBP-3 fragmentation was quantified by densitometric analysis of [125I]IGFBP-3 protease assays. We examined CSFs of 23 children with malignant CNS tumors, 18 children with leukemia, and 13 children with meningitis. The CSF from 38 children who received lumbar punctures to exclude meningitis was used to define the normal range for IGF-I, IGF-II, IGFBP-3, and IGFBP-3 protease activity in CSF. CNS tumor and leukemia patients had normal levels of IGF-I and IGF-II in CSF, whereas the IGF-II concentration in CSF of meningitis patients was elevated (P < 0.0001). Only 2 of 13 (15%) meningitis patients had elevation of CSF IGFBP-3 concentrations, despite high numbers of inflammatory cells. By comparison, elevated IGFBP-3 concentrations were found in the CSF of 16 of 23 (70%) CNS tumor patients and 6 of 7 (86%) CNS tumor patients with microscopically detectable malignant cells in CSF. Twelve of 13 (92%) patients with medulloblastoma or ependymoma and all 7 medulloblastoma/ependymoma patients with malignant cells in CSF had elevated IGFBP-3 concentrations. The IGFBP-3 protease activity in CSF was elevated in 15 of 16 (94%) patients with CNS tumors of high grade histological malignancy. Five of 6 patients (83%) with acute leukemia and microscopically detectable malignant cells in CSF at the time of diagnosis showed elevated IGFBP-3 concentrations, with normalization after chemotherapy. Leukemia patients without malignant cells in CSF had normal IGFBP-3 concentrations. We conclude that in CSF of children with highly malignant CNS tumor or CNS leukemia, IGFBP-3 is elevated. This phenomenon could be caused by disruption of the blood-CSF barrier and entry of IGFBP-3 from serum, although this appears unlikely, especially for CNS leukemia. More likely possibilities are 1) local production of IGFBP-3 by CNS tumor tissue and secretion into the CSF, or 2) local production of IGFBP-3 by malignant cells within the CSF.

Adolescent↗
PubMed1993

Insulin-like growth factor binding protein (IGFBP)-3 levels in conditioned media of Hs578T human breast cancer cells are post-transcriptionally regulated.

Hs578T human breast cancer cells secrete insulin-like growth factor binding protein (IGFBP)-3 (41-kDa and 39-kDa) and IGFBP-4 (24-kDa) as major BP species. In addition, cell surface-associated IGFBP-3 is demonstrable by use of cell monolayer affinity cross-linking or by employing immunoperoxidase staining of the cell surface with specific polyclonal anti-human IGFBP-3 antibodies (alpha IGFBP-3gl and alpha IGFBP-3ngl). In this study, we have demonstrated that regulation of Hs578T IGFBP-3 by IGF peptides is specific, non-receptor mediated, and post-translational by showing: 1) dose-dependent increase of IGFBP-3 in conditioned media(CM) following addition of IGF-I and IGF-II (maximum 8-13-fold increase at 100 ng/ml concentration), but not by insulin up to 1 microgram/ml; 2) confirmation of IGF-induced increases in CM concentrations of IGFBP-3 by means of Western ligand blot, affinity cross-linking, and IGFBP-3-specific radioimmunoassay; 3) increase of IGFBP-3 in CM by addition of IGF analogs which retain full affinity for IGFBPs ([Leu27]IGF-II and [Tyr55,Gln56]IGF-I), but not by IGF analogs which have significantly decreased affinity for IGFBPs ([Gln3,Ala4,Tyr15,Leu16]IGF-I, [Gln6,Ala7,Tyr18,Leu19,Leu27]IGF-II and IGF-I/insulin hybrid); 4) no change in IGFBP-3 mRNA following addition of IGFs; 5) existence of metal ion-dependent IGFBP-3 specific protease in CM and protection of IGFBP-3 from protease by formation of [IGF:IGFBP-3] complexes; and 6) release of cell surface-associated IGFBP-3 into CM by addition of IGF peptides. These studies demonstrate that IGF peptides regulate CM concentrations of IGFBP-3 through non-receptor mediated events, including dissociation of cell surface-associated IGFBP-3 and protection of IGFBP-3 from protease activity.

Blotting, Northern↗
PubMed1992

The insulin-like growth factor II (IGF-II)/mannose 6-phosphate receptor mediates IGF-II-induced motility in human rhabdomyosarcoma cells.

Insulin-like growth factor-II (IGF-II) is an autocrine growth and motility factor for human rhabdomyosarcoma. It interacts with three different receptors: the IGF-I, the IGF-II, and the insulin receptor. A specific function of the IGF-II receptor in mediating IGF-II responses has not been defined. In this report we investigate the mechanism of IGF-II-mediated motility in rhabdomyosarcoma cells. We demonstrate that IGF-II and [Leu27]IGF-II, an analog selective for the IGF-II receptor, stimulate motility at concentrations in which they interact only with their own receptor. An antibody that blocks the IGF-I receptor does not inhibit either peptide activity, while an antibody specific for the IGF-II receptor suppresses the IGF-II-induced motility. This antibody does not interfere with rhabdomyosarcoma cell proliferation. We conclude that in rhabdomyosarcoma cells IGF-II stimulates two different responses mediated by distinct receptors: 1) a mitogenic response through the type I receptor and 2) a motility response through the type II receptor.

Affinity Labels↗
PubMed1992

[Energy balance in repeated under- and overnutrition in model studies in sows].

In a model experiment eight adult sows were used to examine the effect of successive periods of under- and oversupply of energy (MUMU) on thermogenesis and efficiency of energy utilization in comparison to a constant maintenance supply (NNNN). Each treatment sequence was assigned to each animal according to a change-over design over 8 weeks. Before and after the treatment periods all the animals were fed at maintenance level (N). Energy deficiency (M) was performed by use of a basal diet with 45% of maintenance energy requirements and values for all the other nutrients sufficient for requirements. Normal (N) and excessive (U) intakes of energy was provided with supplements of starch. The total inake of gross energy during the periods MUMU was exactly the same as during NNNN. Complete energy balances were performed for each animal and period as well as during the pre- and post-experimental phase. There was no or little response of altered energy intake on carbon and energy excretion in faeces, urine and methane. However, heat production was significantly decreased by 4.1% on energy deficiency, and increased by 15.1% during energy oversupply. Summed up over the total sequence the animals produced 5.4% more heat on MUMU than during NNNN. This response was associated with a mobilization of 1.1 MJ/d tissue energy and a decrease in body weight by 2.0 kg. The efficiency of utilization of ME was 88% with energy undersupply and 75% during overnutrition. Criteria of energy balance did not differ between the pre- and post-treatment periods. It could be demonstrated that the increase in energy expenditure at oversupply was entirely explainable by the so-called obligatory thermogenesis. At the energy deficiency periods the efficiency of energy utilization reflected both energy costs of ingestion and processing of nutrients as well as a slight reduction in metabolic rate. Finally, there were no residual effects of the treatment on the energy expenditure of the animals at the end of the experiment.

Animal Feed↗
PubMed1992

Non-receptor mediated, post-transcriptional regulation of insulin-like growth factor binding protein (IGFBP)-3 in Hs578T human breast cancer cells.

Hs578T human breast cancer cells secrete insulin-like growth factor binding protein 3 (IGFBP-3) as the major BP species. In addition, cell surface-associated IGFBP-3 is demonstrable by the use of cell monolayer affinity cross-linking or immunoperoxidase staining of the cell surface with a specific polyclonal anti-human IGFBP-3 antibody (alpha IGFBP-3 gamma 1). In this study, we have demonstrated that regulation of Hs578T IGFBP-3 by IGF peptides is specific, non-receptor mediated, and post-translational by showing: 1) dose-dependent increase of IGFBP-3 in conditioned media (CM) following addition of IGF-I and -II (maximum 13 fold increase at 100 ng/ml), but not by insulin up to 1 mg/ml; 2) no change in CM IGFBP-3 level by [Gln3,Ala4,Tyr15,Leu16] IGF-I, which has decreased affinity for IGFBPs; 3) no change in IGFBP-3 mRNA following addition of IGFs; 4) release of cell surface-associated IGFBP-3 into CM by the addition of IGFs, but not by [Gln3,Ala4,Tyr15,Leu16]IGF-I. These studies demonstrate that IGF peptides regulate CM concentrations of IGFBP-3 through non-receptor mediated dissociation of cell surface-associated IGFBP-3.

Blotting, Northern↗
PubMed1991

[Digestibility, intestinal passage time and energy value of wheat bran in model studies in sows].

An energy metabolism trial was conducted with four sows allocated to each of four levels of wheat bran (7, 14, 21 or 28 g/kg body weight 0.75.day). During 2-week experimental periods half the number of animals received increasing levels of the wheat bran supplementation, the other sows were fed in decreasing order. The basal diet was given constantly at a level of 36 g/kg Bw 0.75. Total digestibility of energy was determined by the collection method. For partioning the digestible energy into a prececal and postileal component the diet was supplemented with 0.3% Cr2O3, and samples of digesta taken by means of a cecum cannula were analyzed for this marker. The rate of passage of food was evaluated by using plastic pellets fed orally as well as inserted into the cecum. During each experimental period a complete energy balance was performed according to the methods of indirect calorimetry. The digestibility and metabolizability of wheat bran energy over the total alimentary tract was 60% and 57%, respectively. As a percentage of the total digestible energy, 70% were found in the prececal site of the digestive tract, and 30% in the hindgut fermentation. The efficiency of utilization of metabolizable energy (ME) for energy retention was 66.2%. Utilization of hindgut energy was lower by about a quarter than utilization of energy digested in the small intestine. The mean contents of ME of wheat bran amounted to 10.1 kJ/g dry matter. The ME of the wheat bran fiber (non-starch poly-saccharides) was calculated to be 5 kJ/g. The excretion of short-chain fatty acids in the feces was only 1-2% of fecal energy. The rate of passage of food decreased from 78 h (basal diet alone) to 52 h with the highest wheat bran supplementation. The prececal retention time was only 20% of the total rate of passage through the alimentary tract.

Animals↗
PubMed1991

Energy metabolism of lactating dairy cows treated with prolonged-release bovine somatotropin or energy deficiency.

Two experiments were carried out with lactating Simmental x Red Holstein Friesian dairy cows. In the first experiment, 8 cows each received six injections at 4-wk intervals of either saline or 640 mg of prolonged-release bST. In the second experiment, 14 of 20 cows received 20 MJ NEL less than their daily requirement for 3 wk. Digestible and metabolizable energy were not affected by the treatments. Mobilization of body energy compensated the bST-induced increase of milk energy and supported milk production of underfed cows by two-thirds of the net energy deficit. The utilization of mobilized body energy and metabolizable energy from the diet for maintenance and milk production was unchanged. The bST and energy deficiency increased N utilization for milk production, because bST increased milk N secretion at the same N intake, and energy deficiency partly compensated the reduced N intake by N mobilization. Milk yield oscillated between the bST injections. Mean milk yield increased by 2.8 kg at constant milk composition. During energy deficit, milk yield dropped by 1.7 kg with decreasing milk protein content.

Animals↗
PubMed1989

Cellular aspects of retention and transport of inhaled soluble and insoluble actinide compounds in the rat lung.

The binding of 241Am-hydroxide polymers (as models for readily soluble actinide compounds) to the cell components of rat lung was investigated using differential centrifugation, density gradient centrifugation, gel chromatography, carrier-free electrophoresis and electron microscopic autoradiography (with 241Pu). Irregularly shaped and spherical mixed (U, Pu)O2 particles (as models for insoluble actinide compounds) were administered to rats by inhalation and intratracheal installation and the lung and organ retention was determined. Electron microscopic studies were performed with rat lung and with rat and bovine alveolar macrophages exposed to the actinide compounds in vitro. In the case of the mixed (U, Pu)O2 particles the lung retention was independent of the particle shape and route of administration. Whereas 241Am administered as a hydroxide polymer was transferred rapidly from lung to skeleton and liver, only a few percent of the initial alveolar deposit was found in these organs after mixed oxide inhalation. It is concluded that all types of particles are stored primarily within phagolysosomes of alveolar macrophages. In the case of readily soluble compounds, the actinides are solubilized within these lysosomes and become bound to cytosolic ferritin in the alveolar macrophages. They are then released from the macrophages and probably cross the alveolar membranes as transferrin or as low-molecular-weight forms. Insoluble compounds remain within the lysosomes of alveolar macrophages, but there are indications of chemical damage to the lysosomal membranes, causing the particles to lie free in the cytoplasm.

Actinoid Series Elements↗
PubMed1989

Behaviour of spherical and irregular (U,Pu)O2 particles after inhalation or intratracheal instillation in rat lung and during in vitro culture with bovine alveolar macrophages.

Spherical and irregularly shaped mixed (U,Pu) oxide particles were administered to rats by inhalation and by intratracheal instillation. The lung retention of the particles was independent of particle shape and of the route of administration. Only a small percentage of the administered radioactivity was found in other organs. Detailed electron microscopic studies showed particles within membrane-enclosed vacuoles as well as lying free in the cytoplasm.

Administration, Inhalation↗
PubMed1989

[Variability and circadian rhythms of maintenance energy expenditure in adult humans].

Using indirect calorimetry the energy expenditure of healthy subjects was investigated as complete 24-hour balance measurements. The respective data were evaluated with regard to level, variation and normalizing of heat production (HP) and maintenance requirement. Diets were composed of customary ingredients and the intake of energy maintained constant slightly below maintenance requirement during the 14-day experimental period. Faeces and urine were collected for the final 7 days. Exchange of oxygen and carbon dioxide was measured during the last 48 h while the subjects stayed in an open-circuit respiration chamber, furnished like a small living-room. The daily energy balance averaged -0.38 MJ (+/- 0.73). For data evaluation the HP of each subject was corrected to zero energy balance, assuming a calorigenic effect of 10% for mixed diets. The resulting energy requirement of metabolizable energy for maintenance at energy equilibrium amounted to 136 (+/- 17) MJ/kg body weight and 383 (+/- 45) kJ/(kg body weight)0.75, respectively. Scaling the body weight to the 3/4 power diminished slightly the coefficient of variation. The observed total variance of the HP was mainly contributed by the subjects per se (94%), whereas only a small amount was related to day-to-day variability (6%; measurement noise and intraindividual variability). In terms of coefficient of variation the respective values were 11.5 and 2.8%. Comparable assessments with sows showed nearly the same results on animal variance and day-to-day variability. The daily time pattern of HP showed two maxima and two minima. In the morning and evening the HP exceeded the average 24 h value by 19 and 14%, respectively. During afternoon a value of 11% was observed. However, after midnight HP fell 31% under the daily mean. The relation between daily minimum and maximum was 1.7:1. During night the subject standard deviation was 8.6% compared to about 12% in the daytime. It is concluded that the total experimental error observed generally in whole-body indirect calorimetry studies is mostly attributable to subject variability. Furthermore, the variation of energy expenditure may account for deviations up to 10% or more between individual requirement and recommendations for predicting energy requirements.

Adult↗
PubMed1987

[Thermogenesis in humans after varying meal time frequency].

To a group of 8 healthy persons a slightly hypocaloric diet with protein (13% of energy), carbohydrates (46% of energy) and fat (41% of energy) was given as one meal or as five meals in a change-over trial. Each person was 2 weeks on each regimen. Under the conditions of slight undernutrition and neutral temperature the balances of nitrogen, carbon and energy were assessed in 7-day collection periods, and according to 48-hour measurements of gaseous exchange (carbon-nitrogen balance method) by the procedures of indirect calorimetry. Changes of body weight were statistically not significant. At isocaloric supply of metabolizable energy with exactly the same foods in different meal frequencies no differences were found in the retention of carbon and energy. Urinary nitrogen excretion was slightly greater with a single daily meal, indicating influences on protein metabolism. The protein-derived energy was compensated by a decrease in the fat oxidation. The heat production calculated by indirect calorimetry was not significantly different with either meal frequency. Water, sodium and potassium balances were not different. The plasma concentrations of cholesterol and uric acid were not influenced by meal frequency, glucose and triglycerides showed typical behaviour depending on the time interval to the last meal. The results demonstrate that the meal frequency did not influence the energy balance.

Body Water↗