Low parotid saliva calmodulin in patients with taste and smell dysfunction

Parotid saliva calmodulin was found both in 32 normal volunteers and in 60 patients with taste and smell dysfunction; salivary calmodulin concentration was significantly lower in the patients than in the volunteers. There were no differences in salivary calmodulin concentration with respect to age, sex, or salivary flow rate in either normal volunteers or patients. When patients were categorized by diagnosis, calmodulin concentration was found to be decreased in all patient groups. The concentration of calmodulin in saliva was about 10 times that found in serum, suggesting that the parotid gland is a major source of this protein.     

Zinc level in the blood of children with nephrotic syndrome and correction of its deficiency with animal blood preparation Livex]

Serum and erythrocyte zinc levels have been assayed in in 45 children with steroid-dependent nephrotic syndrome in both acute phase and remission. Out of these children a group of 22 has been distinguished. These patients have been treated with Livex--animal blood preparation containing amino acids and trace elements, including zinc. It was found, that serum zinc has been significantly lowered in children with the acute phase of nephrotic syndrome who were not treated with Livex. Erythrocyte zinc levels have been normal in these patients. A significant increase in both serum and erythrocyte zinc levels has been noted during remission, but they have still been lower that in healthy children. A three-month cure with Livex produced statistically significant increase in zinc levels in children during remission.     

The distribution of zinc and copper in plasma, erythrocytes and erythrocyte membranes of rainbow trout (Salmo gairdneri)

1. The zinc and copper concentration of plasma was determined in rainbow trout, lake trout, walleye and whitefish. 2. These fish had mean plasma zinc concentrations ranging from 9.3 to 15.1 ppm and copper concentrations from 0.6 to 1.3 ppm. 3. In rainbow trout, the concentration of zinc and copper is greater in the erythrocyte membrane than in the total erythrocyte. 4. Ultrafilterable plasma zinc and copper concentration in rainbow trout was determined to be 0.03 and 0.019 ppm, respectively. 5. Dialysis of rainbow trout plasma against 20 mM EDTA results in removal of 99% of the zinc and 88% of the copper from plasma proteins.     

Circadian rhythm in the membrane of circulating human blood cells: microviscosity and number of benzodiazepine binding sites. A search for regulation by plasma ions, nucleosides, proteins or hormones

Circadian rhythms in both the number of peripheral type binding sites for benzodiazepines in platelet membranes and the microviscosity of the erythrocyte membrane were demonstrated in 7 healthy men. Neither variable appeared to be linked to each other, or regulated by the plasma concentrations of total or free cortisol, testosterone, potassium, magnesium, calcium, cAMP, cGMP or proteins or by the erythrocytic concentration of magnesium or potassium or by the plasma cAMP:cGMP ratio or by the ratio of intra-erythrocyte:plasma concentrations of potassium or magnesium. A highly significant negative correlation was found between the microviscosity of the erythrocyte membrane and the activity of the membrane-bound enzyme, methyltransferase I. Such a correlation was validated both on raw data and on 24 hr-means (r = 0.84; P less than 0.01). A circadian rhythm in the activity of this enzyme was also demonstrated. Moreover, a highly significant correlation was also found between plasma transcortin concentration (TRC) and microviscosity (r = 0.50, P less than 0.01), and between TRC and methyltransferase I activity (r = 0.61, P less than 0.01). Such findings may constitute clues towards the understanding of the regulation of the circadian rhythm in the fluidity of the red blood cell membrane in man and guide future steps with regard to the role of this rhythm upon the availability of drug binding sites at the cell surface.     

Erythrocyte membrane fluidity and changes in plasma lipid composition: a possible relationship in childhood obesity

We have studied plasma lipid patterns and erythrocyte membrane fluidity in 60 obese children and 20 normal children. Plasma levels of total cholesterol and associated low-density lipoproteins were significantly increased in 20 obese patients with respect to controls. A significant decrease in membrane fluidity, measured as an increase in the fluorescence polarization value of the probe 1,6-diphenyl-1,3,5-hexatriene, associated with an increase in the cholesterol/protein ratio has been shown in obese patients. The study of the correlation between erythrocyte membrane fluidity and plasma cholesterol has indicated that significant changes in fluidity and membrane lipid composition also occur in erythrocytes of obese patients with normal plasma lipid levels. These findings confirm that the erythrocyte membrane responds very early to modifications of plasma lipoproteins and suggest that in childhood obesity a modified transfer of cholesterol from plasma to erythrocyte membrane may take place.     

Whole blood and serum zinc levels in relation to sex and age

The zinc content in whole blood and serum was determined in 239 healthy males and 217 healthy females by atomic absorption spectrophotometry. The mean level of zinc obtained in whole human blood from males was 607.0 +/- 105.3 micrograms/100 ml and in females 585.2 +/- 122.9 micrograms/100 ml. The mean level of zinc in serum was 116.6 +/- 55.2 micrograms/100 ml and 105.2 +/- 66.9 micrograms/100 ml in males and females respectively. The zinc concentration in whole blood and serum in males proved to be slightly higher than in females though the difference is not statistically significant. For the males a positive correlation was found between age and the zinc level in whole blood and serum; this is only statistically significant in whole blood. In females, the zinc level in whole blood showed a positive correlation with age which was not statistically significant, while in serum this correlation was negative and statistically significant.     

Importance of cholesterol-phospholipid interaction in determining dynamics of normal and abetalipoproteinemia red blood cell membrane

Acanthocytic red blood cells in patients with abetalipoproteinemia have a decrease membrane fluidity that is associated with increased sphingomyelin/phosphatidylcholine (SM/PC) ratios. Here we describe studies designed to gain better insight into (i) the interrelationship between the composition of lipoprotein and red blood cell membrane in abetalipoproteinemia patients and normal controls; and (ii) how the differences in lipid composition of the red blood cell membrane affect its fluidity. The increased SM/PC ratio found in abetalipoproteinemia plasma high density lipoproteins (HDL) (3 times greater than controls) was paralleled by an increase in this ratio in acanthocytic red cells, but to a lesser degree (almost twice greater than control red cells). Cholesterol/phospholipid mole ratios (C/P) were increased 3-fold in abetalipoproteinemia HDL, but only slightly increased in red cells compared to controls values. As in the controls, 80-85% of abetalipoproteinemia red cell sphingomyelin was found to be in the outer half of the erythrocyte membrane. Membrane fluidity was defined in terms of microviscosity (eta) between 5 and 42 degrees C by the fluorescent polarization of 1,6-diphenylhexatriene (DPH) present in erythrocyte ghost membranes. At all temperatures, membrane microviscosity was higher in abetalipoproteinemia ghosts than controls, but these differences decreased at higher temperatures (12.34 vs 9.79 poise, respectively at 10 degrees C; 4.63 vs 4.04 poise at 37 degrees C). These differences were eliminated after oxidation of all membrane cholesterol to cholest-4-en-3-one by incubation with cholesterol oxidase. Following cholesterol oxidation, the membrane microviscosity decreased in patient ghosts more than in normal red blood cells so that at all temperatures no significant differences were present relative to control ghosts, in which the apparent microviscosity was also diminished but to a lesser degree. Therefore, although increased SM/PC ratios in abetalipoproteinemia may be responsible for decreased erythrocyte membrane fluidity, these effects are dependent upon normal interactions of cholesterol with red cell phospholipid.     

Estimation of plasma and saliva levels of coenzyme Q10 and influence of oral supplementation

Coenzyme Q10 (CoQ(10)) levels in human saliva were measured by HPLC with a highly sensitive electrochemical detector (ECD) and a special concentration column. This HPLC system showed satisfactory analytical results within the standard range of 0.78-50 ng/ml. We also found a significant correlation between CoQ(10) levels in plasma and in saliva from parotid glands, while this correlation was lacking between plasma CoQ10 and CoQ10 in whole saliva. Unlike in plasma, there are some fluctuations of saliva CoQ(10) levels throughout the day. A good correlation was obtained by collecting parotid gland saliva at times between meals. The mean saliva CoQ(10) level for 55 healthy volunteers was 17.0 ng/ml (S.D. 6.8 ng/ml); approximately one fiftieth of that in plasma. Regarding the influence of oral supplementation, CoQ(10) was analyzed in plasma and parotid gland saliva from 20 healthy volunteers supplemented daily with 100 mg of CoQ(10) for the first week and 200 mg for the second. The plasma CoQ(10) levels of all volunteers increased to different extents in accordance with the CoQ(10) daily intake and the corresponding change in saliva showed almost the same trend.     

Calcium, magnesium, and zinc status in experimental hypothyroidism

In this study, experimental hypothyroidism was established and used to investigate possible alterations in the calcium, magnesium, and zinc homeostasis by assessing their concentration in plasma and erythrocytes. Hypothyroidism was induced by administration of methimazole an iodine blocker at a dose of 75 mg/100 g food for 3 wk. In the methimazole-induced hypothyroid state, the experimental animals showed a significant decrease in plasma zinc concentration, whereas a significant increase in plasma magnesium concentration occurred. No change was observed in plasma calcium concentration. The erythrocyte zinc and calcium concentrations were found to be increased, whereas magnesium concentration decreased. Erythrocyte magnesium concentration showed a significant positive correlation with T₄ values. The study provides evidence for marked alterations in homeostatis of zinc, magnesium, and calcium.     

Importance of cholesterol-phospholipid interaction in determining dynamics of normal and abetalipoproteinemia red blood cell membrane

Acanthocytic red blood cells in patients with abetalipoproteinemia have a decreased membrane fluidity that is associated with increased sphingomyelin/phosphatidylcholine (SM/PC)§ ratios. Here we describe studies designed to gain better insight into (i) the interrelationship between the composition of lipoprotein and red blood cell membrane in abetalipo-proteinemia patients and normal controls; and (ii) how the differences in lipid composition of the red blood cell membrane affect its fluidity. The increased SM/PC ratio found in abetalipoproteinemia plasma high density lipoproteins (HDL) (3 times greater than controls) was paralleled by an increase in this ratio in acanthocytic red cells, but to a lesser degree (almost twice greater than control red cells). Cholesterol/phospholipid mole ratios (C/P) were increased 3-fold in abetalipoproteinemia HDL, but only slightly increased in red cells compared to controls values. As in the controls, 80–85% of abetalipo-proteinemia red cell sphingomyelin was found to be in the outer half of the erythrocyte membrane. Membrane fluidity was defined in terms of microviscosity ({ie116-1}) between 5 and 42°C by the fluorescent polarization of 1,6-diphenylhexatriene (DPH) present in erythrocyte ghost membranes. At all temperatures, membrane microviscosity was higher in abetalipoproteinemia ghosts than controls, but these differences decreased at higher temperatures (12.34 vs 9.79 poise, respectively, at 10°C; 4.63 vs 4.04 poise at 37°C). These differences were eliminated after oxidation of all membrane cholesterol to cholest-4-en-3-one by incubation with cholesterol oxidase. Following cholesterol oxidation, the membrane microviscosity decreased in patient ghosts more than in normal red blood cells so that at all temperatures no significant differences were present relative to control ghosts, in which the apparent microviscosity was also diminished but to a lesser degree. Therefore, although increased SM/PC ratios in abetalipoproteinemia may be responsible for decreased erythrocyte membrane fluidity, these effects are dependent upon normal interactions of cholesterol with red cell phospholipid.     

Identification of cyclophilin as the erythrocyte ciclosporin-binding protein

Previous studies on the distribution of circulating ciclosporin have shown that the majority of the drug is associated with erythrocytes. In order to investigate the nature of ciclosporin-erythrocyte binding, binding studies were performed on isolated erythrocytes. At therapeutic concentrations (approx. 0.5 microgram/ml in whole blood) greater than 90% of the erythrocyte associated ciclosporin was found in the cytosol. The cytosolic binding capacity was approximately (2-2.5).10(5) molecules of ciclosporin per cell. A lower affinity binding of the drug to the plasma membrane occurred only at higher ciclosporin concentrations. The ciclosporin-binding species was purified from erythrocyte cytosol using ciclosporin-Affigel affinity chromatography. This revealed a 16 kDa protein, similar in size to the ciclosporin-binding protein, cyclophilin, previously identified in lymphocyte cytosol. Immunochemical analysis using rabbit anti-bovine spleen cyclophilin antisera revealed that the erythrocyte ciclosporin-binding protein was either cyclophilin or a closely related protein. It is concluded that intracellular ciclosporin-binding within erythrocytes is mostly attributable to the presence of a single protein or protein family represented by cyclophilin. The presence of (2-2.5).10(5) copies of this binding protein within each erythrocyte is responsible for the ciclosporin found associated with erythrocytes.     

Serum fructosamine concentration as measure of blood glucose control in type I (insulin dependent) diabetes mellitus.

Serum fructosamine activity was studied in 42 patients with type I (insulin dependent) diabetes mellitus and 30 non-diabetic volunteers as an index of blood glucose control. There was a significant correlation both between fructosamine and glycosylated haemoglobin values (r = 0.82) and between fructosamine and the fasting C peptide concentration (r = -0.81). Test results in 14 of the diabetics reflected the mean plasma glucose concentration calculated from 25 serial estimations in a single 24 hour period (r = 0.75; p less than 0.01) but not the mean amplitude of glycaemic excursion (r = 0.23; p greater than 0.05). Fructosamine concentrations measured in these multiple blood specimens did not change significantly throughout the day (mean coefficient of variation 4.1%) despite wide variability of the respective plasma glucose concentrations (mean coefficient of variation 36.2%). It is concluded that a single random serum sample analysed for fructosamine concentration provides a simple and reliable assessment of glucose homoeostasis in patients with type I diabetes mellitus.     

Plasma and erythrocyte lipid peroxide levels in workers with occupational exposure to lead

The plasma and erythrocyte lipid peroxide levels were measured in a group of male subjects occupationally exposed to lead for an average period of 17 yr, and compared to those from an age-matched control group living in the same city in a similar socioeconomical environment. The blood lead and plasma zinc levels were measured by atomic absorption spectroscopy. The plasma and erythrocyte lipid peroxide levels were established by the malondialdehyde determination method. Significant differences were found in the blood lead levels in lead-exposed workers, 15.00±10.15 μg/dL as compared to controls, 2.37±0.89 μg/dL. The plasma (2.67±0.69 μM) and erythrocyte (27.53±6.28 nmol/g Hb) lipid peroxide levels in workers with occupational exposure to lead were significantly higher than controls, 1.23±0.61 μM and 14.35±2.08 nmol/g Hb, respectively. There were no significant differences of the zinc levels in both groups. The blood lead levels had a statistically significant positive correlation with age and with duration of exposure in both groups, but showed no relationship to the corresponding blood zinc levels. The results presented in this study indicate that the increase of plasma and erythrocyte lipid peroxide levels in workers exposed to lead may be related to the lead concentration, age and duration of exposure.     

Rapid and direct determination of selenium, copper, and zinc in blood plasma by flow injection-inductively coupled plasma-mass spectrometry

A flow injection-inductively coupled plasma-mass spectrometry (FI-ICP-MS) with a simple sample preparation procedure was developed for the determination of selenium, copper, and zinc in blood serum/plasma. A serum/plasma sample was filtered through a 0.45-μm membrane filter and diluted with a mixture of trace elements in a standard solution (9∶1, v/v). Measurement of the reference serum sample confirmed the accuracy of our method for selenium, copper, and zinc concentration. In the case of blood plasma samples obtained from six healthy adult males, the selenium, copper, and zinc concentrations were similar to those of a typical healthy male in Japan. These results suggest that the sample prepartive procedure coupled with FI-ICP-MS can be used for the routine determination of selenium, copper, and zinc in human blood serum/plasma.     

Serum, zinc, copper and insulin in diabetes mellitus

We studied serum zinc, copper, ceruloplasmin, insulin, basal glycemia and cholesterol in 49 diabetics on oral anti-diabetic agent and in 10 normal people. We found there is an elevation of serum zinc, copper and ceruloplasmin in the diabetic group that is statistically significant (p less than 0.001). There is a significant correlation between zinc and insulin (p less than 0.001), and between the quotient zinc/copper and cholesterol (p less than 0.001). The increase of plasma zinc can reflect a deficient storage or a chronic hypersecretion of insulin in hyperglucemic patients. We think that the quotient zinc/copper/might play a role in the pathogenesis of the arteriosclerosis in diabetes.     

Alterations in erythrocyte membrane lipid and fatty acid composition in Chediak-Higashi syndrome

Chediak-Higashi syndrome (CHS) is an autosomal recessive disease characterized by the presence of abnormally large cytoplasmic organelles in all body granule producing cells. The molecular mechanism for this disease is still unknown. Functional disorders in membrane-related processes have been reported. Erythrocyte membranes from four CHS patients and 15 relatives including obligatory heterozygous were studied to examine potential alterations in the lipid and fatty acid profile of erythrocyte membranes associated with this syndrome. Plasma concentrations of cholesterol, triglycerides, phospholipids, and apolipoproteins AI and B100, and the lipid components of very low-, intermediate-, low- and high-density lipoproteins were also determined. CHS erythrocyte membranes were found to be enriched with lipids in relation to protein and to show: (1) an increase in cholesterol and choline-containing phospholipids (sphingomyelin and phosphatidylcholine) that predominate in the outer monolayer, which is higher than the increase in phosphatidylserine and phosphatidylethanolamine, that are chiefly limited to the inner monolayer in normal red blood cells; (2) a relative palmitic acid and saturated fatty acid increase and arachidonic acid and unsaturated fatty acid decrease, this resulting in a lower unsaturation index than controls. Changes in CHS erythrocyte membrane lipids seem to be unrelated to serum lipid disorders as plasma lipid and apolipoprotein concentrations were apparently in the normal range, with the exception of a modest hypertriglyceridemia in patients and relatives and a decreased concentration of HDL cholesterol in patients. These findings indicate that CHS erythrocyte membranes contain an abnormal lipid matrix with which membrane proteins are defectively associated. The anomalous CHS membrane composition can be explained on the postulated effects of the CHS1/Lyst gene.     

Effect of menstrual cycle hormones on cation transport in the red-cell membrane

Erythrocyte cation transport, plasma prorenin and renin and sexual hormones were sequentially evaluated in 12 normal volunteers over the menstrual cycle. Na-K cotransport and Na-Li countertransport raised in 6 out of 12 subjects in synchronization with the ovulatory phase. When the maximal % variation (ovulatory phase) versus baseline (follicular phase) of the Na-K cotransport was plotted versus the maximal % increment of oestrogens. A direct, highly significant inverse correlation was observed (r = 0.904, p less than 0.001). Moreover, a highly significant inverse correlation between plasma prorenin and intraerythrocyte Na (r = -0.857, p less than 0.001) in the follicular phase was found. Our data suggest that erythrocyte cation transport can be influenced by sexual hormones in human.     

Effect of vitamin C and zinc on osmotic fragility and lipid peroxidation in zinc-deficient haemodialysis patients

Peroxidation of the membrane lipid structure of red blood cell leads to haemolysis and anaemia in haemodialysis patients. Dietary constituents of antioxidant vitamins and trace elements may play an important role in protecting against oxidant damage. In this study, the effects of supplementation of vitamin C and zinc on osmotic fragility and lipid peroxidation of erythrocytes were investigated in 34 zinc-deficient haemodialysis patients. Sixteen sex- and age-matched normal volunteers acted as controls. Patients were randomized to receive vitamin C (250 mg day(-1)), zinc (20 mg day(-1)) or a placebo treatment for 3 months. The levels of vitamin C, zinc, malondialdehyde (MDA) and osmotic fragility were measured initially and 3 months after supplementation. Mean serum concentration of vitamin C and zinc increased significantly in the groups at the end of the respective study periods. Supplementation with vitamin C and zinc improved osmotic fragility, and decreased the level of MDA in the groups, but some side-effects (i.e. nausea, vomiting, fever, muscle pain, weakness) were observed during the zinc treatment. The results showed that the supplementation of both treatments decreased osmotic fragilty and MDA in zinc-deficient haemodialysis patients. However, vitamin C treatment was found to be safer than zinc supplementation.     

Effect of end-stage renal disease and diabetes on zinc and copper status

The aim of this study was to compare the nutritional status of zinc and copper in patients with and without diabetes submitted to chronic hemodialysis. Thirty-three patients with type 2 diabetes (DM group), 30 nondiabetic patients (NDM group), and 20 healthy individuals (control group) were studied. Plasma, erythrocyte, and urinary zinc and plasma copper were obtained from atomic absorption spectrophotometry and ceruloplasmin by immunonephelometry. The anthropometric parameters were similar among the groups. Plasma zinc was lower and erythrocyte zinc was higher in the DM and NDM groups in relation to the control group. No difference in urinary zinc was observed comparing the groups. Plasma copper was higher in the DM group when compared to the NDM and control groups. Ceruloplasmin was similar in the three groups. Serum urea was a positive independent determinant of plasma zinc concentrations. The determinants of erythrocyte zinc were MAMC midarm nuscle circumference and Kt/V dialysis adequacy. The determinants of plasma copper concentration were serum creatinine and serum glucose. The results of this study demonstrate an alteration in the distribution of zinc of patients with chronic kidney disease (CKD) independently of the presence of DM. Also, the status of copper seems not to be influenced by CKD, but only by the metabolic derangements associated with diabetes.     

Increased heme catabolism in critically ill patients: correlation among exhaled carbon monoxide, arterial carboxyhemoglobin, and serum bilirubin IXalpha concentrations

It has been reported that exhaled carbon monoxide (CO) concentrations and arterial carboxyhemoglobin (CO-Hb) concentration in blood may be increased in critically ill patients. However, there was no study that examined correlation among amount of CO in exhaled air, CO-Hb concentrations in erythrocytes, and bilirubin IXalpha (BR) in serum, i.e., the three major indexes of heme catabolism, within the same subject. Here, we examined CO concentrations in exhaled air, CO-Hb concentrations in arterial blood, and BR levels in serum in 29 critically ill patients. Measurements of exhaled CO, arterial CO-Hb, and serum total BR have been done in the intensive care unit. As control, exhaled CO concentration was also measured in eight healthy volunteers. A median exhaled CO concentration was significantly higher in critically ill patients compared with control. There was significant correlation between CO and CO-Hb and CO and total BR level. We also found CO concentrations correlated with indirect BR but not direct BR. Multivariate linear regression analysis for amount of exhaled CO concentrations also showed significant correlation with CO-Hb and total BR, despite the fact that respiratory variables of study subjects were markedly heterogeneous. We found no correlation among exhaled CO, patients' severity, and degree of inflammation, but we found a strong trend of a higher exhaled CO concentration in survivors than in nonsurvivors. These findings suggest there is an increased heme breakdown in critically ill patients and that exhaled CO concentration, arterial CO-Hb, and serum total BR concentrations may be useful markers in critically ill conditions.