The impact of micronutrient supplementation in alcohol-exposed pregnancies on reaction time responses of preschoolers in Ukraine.

The potential of micronutrients to ameliorate the impact of prenatal alcohol exposure (PAE) on attentional regulation skills was explored in a randomized clinical trial conducted in Ukraine. Women who differed in prenatal alcohol use were recruited during pregnancy and assigned to one of three groups [No study-provided supplements, Multivitamin/Mineral Supplement (MVM), or MVM plus Choline]. Their offspring were seen in the preschool period and a reaction time task was administered. Participants were asked to press a response button as quickly as possible as 30 stimuli from the same category (animals) were presented consecutively and then followed by six stimuli from a novel category (vehicles). Number correct, mean latency of the response over trials, and variability in the latency were analyzed separately by sex. During the initial animal trials, boys whose mothers received MVM during pregnancy had more correct responses and reduced response latency compared to boys whose mothers had no MVM treatment. During vehicle trials, maternal choline supplementation was associated with increased response speed in males without a PAE history. Females receiving supplements did not show the same benefits from micronutrient supplementation and were more adversely impacted by prenatal alcohol exposure. Relationships between maternal levels of choline, betaine, and dimethylglycine (DMG) and task performance were also assessed. Although no effects were found for choline after adjusting for multiple comparisons, lower baseline DMG level was associated with greater accuracy and shorter latency of responses in the initial animal trials and shorter latency in the vehicle trials in female preschoolers. Level of betaine in Trimester 3 was associated with reduced variability in the latency of male responses during the animal trials. Maternal micronutrient supplementation in pregnancy appears to improve preschool reaction time performance, but the effects varied as a function of sex and PAE exposure status.

The impact of micronutrient supplementation in alcohol-exposed pregnancies on information processing skills in Ukrainian infants.

The potential of micronutrients to ameliorate the impact of prenatal alcohol exposure (PAE) was explored in a clinical trial conducted in Ukraine. Cardiac orienting responses (ORs) during a habituation/dishabituation learning paradigm were obtained from 6 to 12 month-olds to assess neurophysiological encoding and memory. Women who differed in prenatal alcohol use were recruited during pregnancy and assigned to a group (No study-provided supplements, multivitamin/mineral supplement, or multivitamin/mineral supplement plus choline supplement). Heart rate was collected for 30 s prior to stimulus onset and 12 s post-stimulus onset. Difference values (∆HR) for the first 3 trials of each condition were aggregated for analysis. Gestational blood samples were collected to assess maternal nutritional status and changes as a function of the intervention. Choline supplementation resulted in a greater ∆HR on the visual habituation trials for all infants and for the infants with no PAE on the dishabituation trials. The latency of the response was reduced in both conditions for all infants whose mothers received choline supplementation. Change in gestational choline level was positively related to ∆HR during habituation trials and levels of one choline metabolite, dimethylglycine (DMG), predicted ∆HR during habituation trials and latency of responses. A trend was found between DMG and ∆HR on the dishabituation trials and latency of the response. Supplementation did not affect ORs to auditory stimuli. Choline supplementation when administered together with routinely recommended multivitamin/mineral prenatal supplements during pregnancy may provide a beneficial impact to basic learning mechanisms involved in encoding and memory of environmental events in alcohol-exposed pregnancies as well as non- or low alcohol-exposed pregnancies. Changes in maternal nutrient status suggested that one mechanism by which choline supplementation may positively impact brain development is through prevention of fetal alcohol-related depletion of DMG, a metabolic nutrient that can protect against overproduction of glycine, during critical periods of neurogenesis.

Multinutrient supplement containing ephedra and caffeine causes weight loss and improves metabolic risk factors in obese women: a randomized controlled trial.

OBJECTIVE: To determine the safety and efficacy of a dietary supplement with a low dose of ephedra and caffeine in overweight/obese premenopausal female subjects. DESIGN: A 9-month, double-blind, randomized control study compared the efficacy and safety of a dietary supplement with ephedra and caffeine to a control supplement. SUBJECTS: Sixty-one healthy, premenopausal women with body mass index (BMI) from 27 to 39 kg/m2 were randomly assigned and received a dietary supplement (40 mg/day ephedra alkaloids, 100 mg/day caffeine, high potency mixture of vitamins, minerals, omega-3 fatty acids) or a control supplement for 9 months. EFFICACY: changes in body weight, body composition, lipids, insulin, leptin, adiponectin, ghrelin, and self-reports of physical activity, diet and quality of life indices. SAFETY: blood pressure, heart rate, electrocardiograms, urinalysis, blood histology, serum chemistry measures and self-reported symptoms. RESULTS: Forty-one women completed the study. The treatment group lost significantly more body weight (-7.18 kg) and body fat (-5.33 kg) than the control group (-2.25 and -0.99 kg, respectively), and showed significant declines in heart rate, serum cholesterol, triglycerides, cholesterol to high-density lipoprotein ratio, glucose, fasting insulin, and leptin. Blood pressure, electrocardiograms, other clinical chemistry measures, blood histology, urinalysis, and self-reported physical activity were similar in the groups. Minor symptoms included dry mouth, insomnia, nervousness and palpitations. The treatment group reported more energy and decreased appetite compared to controls and scored higher on a quality of life domain assessing vitality. CONCLUSION: A dietary supplement containing a low potency ephedra/caffeine mixture appeared safe and effective in causing loss of weight and body fat, and improving several metabolic parameters, including insulin sensitivity and lipid profiles when tested under physician supervision. Such supplements could be a useful tool to assist with weight loss.

Dissociation of body growth and adipose deposition effects of growth hormone in oMt1a-oGH transgenic mice.

Chronic highly elevated expression of a growth hormone (GH) transgene enhances overall body growth with minimal adipose accretion, while moderate levels of circulating GH fail to enhance body growth yet promote adipose deposition. These findings suggest that the growth response to GH can be dissociated from adipose effects. This hypothesis was tested in the oMtla-oGH transgenic mouse model by titrating circulating GH levels through variable induction of transgene expression. Circulating GH levels in female transgenics were approximately 49, 132, and 750 ng/ml in response to the transgene stimulus at 0, 15, and 25 mM zinc sulfate, respectively. The highest level of circulating GH generated the largest body weight with the smallest fat accrual while the intermediate GH level generated a body weight equivalent to that for the highest GH but the heaviest gonadal fat pads. The lowest GH levels did not increase body size but did enlarge fat depots. Animals exposed to the highest level of GH had an extended growth phase relative to lower GH levels and the nontransgenic controls. In contrast, the duration of the growth phase for the 0 and 15 mM zinc stimulated transgenics was abbreviated relative to the growth phase of the control animals. The two highest levels of circulating GH increased all forms of the GH receptor, IGF-I, and hepatic lipoprotein lipase mRNA. The growth differential observed for the 0 vs. the 15 mM zinc stimulated transgenics may reflect the preferential increase in the full length GH receptor mRNA and the induction of the smaller IGF-I transcripts with the higher circulating GH while the lipid accrual paralleled the disproportionate induction of the truncated GH receptor mRNA form. Liver and bone content of zinc, manganese, copper, and iron primarily reflected dietary zinc supplementation and did not appear to play a role in the differential growth response. The dissociation of GH effects on growth and adipogenesis as a function of circulating GH levels suggests that the level of GHR and IGF-I expression acts through a threshold mechanism and low expression results in adipogenesis while high expression generates body growth.

Effect of cocoa flavanols and their related oligomers on the secretion of interleukin-5 in peripheral blood mononuclear cells.

We previously showed that flavanols and their related oligomers (FLO) isolated from cocoa can have immunomodulatory effects on production of the cytokines interleukin-1beta (IL-1beta), IL-2, and IL-4. In the present study, we examined whether selected FLO fractions isolated from cocoa (monomer through decamer) modulate IL-5 protein secretion from resting and phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC). Although FLO fractions were unstimulatory for IL-5 secretion in resting cells, PHA-induced IL-5 release from PBMC was markedly affected by certain FLO fractions. The monomeric and small oligomeric (dimer and trimer) fractions enhanced PHA stimulation by 50%, 54%, and 43%, respectively. In contrast, the larger oligomeric fractions (hexamer through decamer) inhibited IL-5 release in the range of 18% to 39%; the tetramer and pentamer showed intermediate effects. The increment in IL-5 suggests that FLO may preferentially stimulate immunoglobulin A. We suggest that in the oral cavity this could result in reduction in the risk for dental caries and periodontal disease. This work offers additional data for consideration of the health benefits of dietary FLO from a variety of foods, including those benefits associated specifically with consumption of some cocoas and chocolates.

Chocolate: food as medicine/medicine as food.

Cocoa and chocolate products have been delicacies for hundreds of years. Only recently have they been recognized as significant sources of phytochemicals with healthful effects. These foods are among the most concentrated sources of the procyanidin flavonoids, catechin and epicatechin. Recent studies have shown that these polyphenols are absorbed from the intestine of animals and humans with epicatechin absorbed much more than catechin. These flavonoids have potent antioxidant and antiplatelet activities following consumption of cocoa or chocolate.

Plasma extracellular superoxide dismutase activity in healthy pregnant women is not influenced by zinc supplementation.

We hypothesized that plasma extracellular superoxide dismutase (EC-SOD) activity reflects the zinc nutriture of healthy pregnant women. Sixty-three women were selected from 580 African-American women who participated in a clinical trial to evaluate the effect of prenatal zinc supplementation on pregnancy outcome. Half of the women received zinc (25 mg/d) and the other half was given a placebo from about 19 wk gestation to delivery. In the trial, a positive effect of zinc supplementation on birthweight was observed, indicating that the population as a whole had suboptimal zinc nutriture. Using plasma samples obtained during the trial, EC-SOD activities were measured and the values were compared with plasma zinc concentrations and plasma alkaline phosphatase activities. Plasma EC-SOD activities in our subjects were lower than previously published values for healthy adults in Korea. Although plasma EC-SOD activity may reflect severe zinc deficiency, it is not a sensitive marker for marginal deficiency status. Plasma EC-SOD activities did not prove to be a better indicator of zinc nutriture of pregnant women than either plasma zinc or plasma alkaline phosphatase activities.

Vitamin and mineral supplement use by healthy teenagers in Korea: motivating factors and dietary consequences.

The use of vitamin and mineral supplements is increasing among young individuals. We surveyed 972 Korean teenagers (age 13-18 y ) for their use of vitamin/mineral supplements, their motivational factors, and the dietary consequences of supplement use. Prevalence of vitamin/mineral supplement use was 31%. Supplement use was highest in high-school students, females, individuals living in rural communities, and individuals from families in high socioeconomic strata. The supplements used most frequently were vitamin C, multivitamins, and vitamin A. Supplement users had a more positive view of the potential health benefits of supplements than did non-users. Most supplements were taken daily. Vitamins B2, B6, and C were the most frequently ingested nutrients from vitamin/mineral supplements. Vitamin/mineral intakes from supplements had a wide range, with mean intakes typically exceeding Korean or the U.S./Canadian recommended dietary allowances. Vitamins B12, B1, and C and iron comprised 2770%, 1930%, 1120%, and 1026%, respectively, of the Korean recommended dietary allowances. When nutrient intakes from the diet and supplements were combined, intakes of niacin, vitamin C, and iron exceeded the recommended upper-intake levels for these nutrients. The health benefits and risks of supplement use by teenagers merits further study.

Shosaiko-to and other Kampo (Japanese herbal) medicines: a review of their immunomodulatory activities.

The use of alternative medicine, including consumption of herbal products and dietary supplements, has been increasing substantially both in the United States and in Western Europe. One area that is garnering increased attention is the use of Oriental Medicine including Kampo, or Japanese herbal medicine. Herein, we review representative examples of research available on the most common use of Kampo medicinals, namely to improve the immune response. We also provide an extensive background on the history of Kampo. There are more than 210 different Kampo formulae used in Japan and most uses of Kampo are to modulate the immune response, i.e. to improve immunity. We have extracted data on seven common Kampo medicinals, and the data are reviewed with respect to in vitro and in vivo activities for both humans and experimental animals; the ingredients as well as the problems with classification of these materials are presented. Research suggests that Kampo herbals are biologically active and may have therapeutic potential. While it is believed that Kampo medicines have few side effects, there is a paucity of data on their toxicity as well as a relative lack of knowledge of the bioactive constituents and potential drug interactions of these agents.

Chronic marginal iron intakes during early development in mice result in persistent changes in dopamine metabolism and myelin composition.

Marginal iron (Fe) deficiency is prevalent in children worldwide, yet the behavioral and biochemical effects of chronic marginal Fe intakes during early development are not well characterized. Using a murine model, previous work in our laboratory demonstrated persistent behavioral disturbances as a consequence of marginal Fe intakes during early development. In the present study, Swiss-Webster mice fed a control Fe diet (75 microgram Fe/g diet, n = 13 litters) or marginal Fe diet (14 microgram Fe/g diet, n = 16 litters) during gestation and through postnatal day (PND) 75 were killed on PND 75 for assessment of tissue mineral concentrations, dopamine metabolism, myelin fatty acid composition, and c- and m-aconitase activities. In addition, these outcomes were assessed in a group of offspring (n = 13 litters) fed a marginal Fe diet during gestation and lactation and then fed a control diet from PND 21-75. Marginal Fe mice demonstrated significant differences in brain iron concentrations, dopamine metabolism and myelin fatty acid composition relative to control mice; however, no difference in c- or m-aconitase activity was demonstrated in the brain. The postnatal consumption of Fe-adequate diets among marginal Fe offspring did not fully reverse all of the observed biochemical disturbances. This study demonstrates that chronic marginal Fe intakes during early development can result in significant changes in brain biochemistry. The persistence of some of these biochemical changes after postnatal Fe supplementation suggests that they are an irreversible consequence of developmental Fe restriction.

Chronic marginal iron intakes during early development in mice alter brain iron concentrations and behavior despite postnatal iron supplementation.

The objective of this study was to investigate the behavioral and cognitive outcomes associated with chronic marginal iron (Fe) intakes during early development. Offspring (3 males and 3 females/litter) of Swiss-Webster female mice who had been fed a control Fe diet (75 microg Fe/g diet) or marginal Fe diet (14 microg Fe/g diet) for 9 wk before mating were weaned on postnatal (PND) 21. Offspring of marginal Fe dams were fed either the marginal Fe diet (marginal group) or a control diet (replete group) from PND 21 throughout the duration of the study, whereas offspring of control dams consumed the control diet ad libitum (control group). On PND 30, 45 and 60, one male and female per litter underwent grip strength and auditory startle testing. A Morris maze was used to assess cognitive function in males starting at PND 50. Marginal Fe mice consistently demonstrated significantly lower grip strength, which was independent of differences in body weight. In addition, marginal Fe males demonstrated attenuated startle responsiveness, as well as altered performance in the Morris water maze. These differences in performance were found in association with lower brain Fe concentrations. Postnatal Fe supplementation did not reverse all of these disturbances because differences in brain Fe concentrations and maze learning persisted. This study demonstrates that chronic marginal Fe intakes during early development can result in persistent biochemical and behavioral changes in mice.

Inflammation and Native American medicine: the role of botanicals.

There is a growing interest in medicinal botanicals as part of complementary medicine in the United States. In particular, both physicians and consumers are becoming aware of the use of herbals by Native American societies; many botanicals sold today as dietary supplements in the United States were used by Native Americans for similar purposes. Yet, these supplements represent only a small number of the >2500 different plant species from vascular taxa, and >2800 species from all taxa, known to have been prized for their medicinal properties by the indigenous inhabitants of the North American continent. We review some of the studies of the immunomodulatory activities of botanicals used by native peoples of North America, the bioactive constituents responsible for those activities, and the mechanisms by which these constituents might modulate the immune system. We focus particularly on 3 species of purple coneflower (ECHINACEA:) because of the widespread use of purple coneflower in the United States to boost immunity and prevent upper respiratory infections. Seven of the 10 most common botanicals sold in the United States were used extensively by Native Americans. However, there are very few data to support such use and even less information about drug toxicity or interactions.

Effects of topical and oral vitamin E on pigmentation and skin cancer induced by ultraviolet irradiation in Skh:2 hairless mice.

This study investigates whether supplementation with topical RRR-alpha-tocopherol (Eol), topical RRR-alpha-tocopheryl succinate, and oral RRR-alpha-tocopheryl acetate can reduce the incidence of acute and chronic damage to the skin (i.e., sunburn and pigmentation and skin cancer, respectively) induced by ultraviolet (UV) irradiation to mice. Groups of twenty Skh:2 female hairless pigmented mice were treated with 1) lotion vehicle, 2) 5% Eol lotion, 3) 5% topical RRR-alpha-tocopheryl succinate lotion, or 4) lotion vehicle and oral RRR-alpha-tocopheryl acetate. Within each group, 15 mice were exposed to 0.24 J/cm2 of UV-B radiation three times per week. The animals' weights and food intakes were monitored, and the vitamin E concentrations of skin, liver, and adipose tissue were measured to determine whether the topical Eol resulted in significant tissue levels. Skin pigmentation was scored, and the total number of clinically detectable skin tumors per animal was counted weekly. Results showed that the skin concentrations of Eol, as well as levels in the adipose tissue, were increased after topical application. Mice treated with each form of vitamin E showed no signs of toxicity and had significantly less acute and chronic skin damage induced by UV irradiation, as indicated by reduced inflammation and pigmentation and by later onset and lesser incidence of skin cancer.

Behavioral and hematologic consequences of marginal iron-zinc nutrition in adolescent monkeys and the effect of a powdered beef supplement.

BACKGROUND: The adolescent growth spurt and menarche increase iron and zinc needs and could precipitate functional deficiencies if dietary sources are inadequate. OBJECTIVE: The effects of mild, combined zinc and iron deprivation during the growth spurt and the ability of meat as a common dietary source of zinc and iron to reverse these effects was studied. DESIGN: Pubertal female rhesus monkeys were fed control diets (n = 8) or diets marginally deficient in zinc (2 microg/g diet; n = 8) and iron (10 microg/g diet; n = 8) for 3 mo. A powdered beef supplement (104 microg Zn/g and 43 microg Fe/g, 11 +/- 2 g/d) was then fed daily to half of the deprived group for 3 additional months. RESULTS: Growth and hematology were not affected significantly by iron-zinc deprivation, but plasma zinc and iron were somewhat lower in the deprived group than in the control group after 3 mo. The deprived monkeys reduced their participation in behavioral testing, responded more slowly and less frequently to test stimuli, and were less active. The beef supplement increased participation in testing and stabilized activity levels, but response times remained depressed. Plasma ferritin was lower in the nonsupplemented deprived monkeys than in the controls by the end of the experiment. Four of 8 of the deprived monkeys had iron deficiency anemia compared with none of the controls and 1 of 8 who received the beef supplement. CONCLUSIONS: Marginal zinc and iron deprivation in early adolescence can lead to behavioral and hematologic dysfunction in nonhuman primates and dietary beef supplements can prevent and reverse some of these effects.

Activation of chick tendon lysyl oxidase in response to dietary copper.

Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in connective tissue. Herein, we assess the extent to which tissue copper concentrations and lysyl oxidase activity are related because the functional activity of lysyl oxidase and the copper content of chick tendon are both related to dietary copper intake. Chicks (1-d old) were fed diets (basal copper concentration, 0.4 microg/g diet) to which copper was added from 0 to 16 microg/g diet. Liver and plasma copper levels tended to normalize in chickens that consumed from 1 to 4 microg copper/g of diet, whereas tendon copper concentrations suggested an unusual accumulation of copper in chickens that consumed 16 microg copper/g diet. The molecular weight of lysyl oxidase was also estimated using matrix-assisted laser desorption ionization/time-of-flight/mass spectrometry (MALDI/TOF/MS). A novel aspect of these measurements was estimation of protein mass directly from the surface of chick tendons and aortae. Whether copper deficiency (0 added copper) or copper supplementation (16 microg copper/g of diet) caused changes in the molecular weight of protein(s) in tendon corresponding to lysyl oxidase was addressed. The average molecular weight of the peak corresponding to lysyl oxidase in tendon and aorta from copper-deficient birds was 28,386 Da +/- 86, whereas the average molecular weight of corresponding protein in tendon from copper-supplemented birds was 28,639 Da +/- 122. We propose that the shift in molecular weight is due in part to copper binding and the formation of lysyl tyrosyl quinone, the cofactor at the active site of lysyl oxidase.

Chronic feeding of a low boron diet adversely affects reproduction and development in Xenopus laevis.

The aims of this work were as follows: 1) to determine whether a purified diet currently used for studies with rats was acceptable for reproductive studies in frogs; and 2) to determine whether frogs are sensitive to a deficit of boron (B) in the diet. Adult Xenopus laevis were fed a nonpurified beef liver and lung (BLL) diet (310 microg B/kg), a purified diet supplemented with boron (+B; 1850 microg B/kg), or a purified diet low in boron (-B; 45 microg B/kg) for 120 d. Frogs fed the BLL and +B diets produced 11.3 and 12.2% necrotic eggs, respectively. Abnormal gastrulation occurred in <4% of the fertilized eggs in both groups, and 96-h larval survival exceeded 75% in both groups. In contrast, frogs fed the -B diet for 120 d produced a high proportion of necrotic eggs (54%). Fertilized embryos from the -B diet-fed frogs showed a high frequency of abnormal gastrulation (26.8%), and >80% of the embryos died before 96 h of development. Mean embryo cell counts at X. laevis developmental stage 7.5 (mid-blastula) were significantly lower in the -B embryos than in the BLL or +B embryos. BLL and -B embryos grown in low boron culture media had a high frequency of malformations compared with embryos grown in boron-supplemented media. These studies show that a purified diet that has been used in rodent studies was acceptable for reproduction studies in X. laevis. This work also demonstrates that a diet low in boron markedly impairs normal reproductive function in adult X. laevis, and that administration of the low boron diet results in an increase in both incidence and severity of adverse effects. In addition, these studies demonstrate the usefulness of the X. laevis model in nutrition studies.

Mushrooms, tumors, and immunity.

Medicinal properties have been attributed to mushrooms for thousands of years. Mushroom extracts are widely sold as nutritional supplements and touted as beneficial for health. Yet, there has not been a critical review attempting to integrate their nutraceutical potential with basic science. Relatively few studies are available on the biologic effects of mushroom consumption, and those have been performed exclusively in murine models. In this paper, we review existing data on the mechanism of whole mushrooms and isolated mushroom compounds, in particular (1-->3)-beta-D-glucans, and the means by which they modulate the immune system and potentially exert tumor-inhibitory effects. We believe that the antitumor mechanisms of several species of whole mushrooms as well as of polysaccharides isolated from Lentinus edodes, Schizophyllum commune, Grifola frondosa, and Sclerotinia sclerotiorum are mediated largely by T cells and macrophages. Despite the structural and functional similarities of these glucans, they differ in their effectiveness against specific tumors and in their ability to elicit various cellular responses, particularly cytokine expression and production. Unfortunately, our data base on the involvement of these important mediators is still rather limited, as are studies concerning the molecular mechanisms of the interactions of glucans with their target cells. As long as it remains unclear what receptors are involved in, and what downstream events are triggered by, the binding of these glucans to their target cells, it will be difficult to make further progress in understanding not only their antitumor mechanisms but also their other biological activities.

Patterns of vitamin/mineral supplement usage by adolescents attending athletic high schools in Korea.

An excessive use of vitamin/mineral supplements is considered by many to be a common health problem. We surveyed 1,355 adolescent boys and girls attending athletic high schools in Korea for their usage patterns of vitamin/mineral supplements. The usage rate of the vitamin/mineral supplements was 35.8%. The most favored supplements were vitamin C, multivitamins, and calcium. The reasons most cited for taking supplements were "to recover from fatigue," and "to maintain health." Vitamin and mineral intakes occurred over a wide range; mean intake values were typically higher than the Korean RDA. Vitamins B1, B12 and C were consumed in very high amounts at 29.7, 17.9 and 11.1 times the Korean RDA, respectively. When the intakes of nutrients from supplements and diet were combined, it was observed that the intakes of niacin, folic acid, vitamin C, and iron exceeded levels that have been proposed as upper safe limits. The above data underscore the need to provide sound nutritional education to athletic adolescents and their coaches with respect to the use of vitamin/mineral supplements and the links between adequate diet, good health, and physical performance.

Rat embryos cultured under copper-deficient conditions develop abnormally and are characterized by an impaired oxidant defense system.

Rat embryos (gestation days 9.0 and 10.0) obtained from dams that were fed a Cu-adequate (8 micrograms Cu/g) or Cu-deficient (< 0.5 micrograms Cu/g diet were cultured for 48 hr in Cu-adequate (16.2 microM) or Cu-deficient (1.0 microM) rat serum. Control embryos cultured in control serum were morphologically normal. Embryos from Cu-deficient dams developed abnormally when cultured in Cu-deficient serum; the abnormalities included distended hindbrains, blisters, blood pooling, and cardiac defects. Control embryos cultured in Cu-deficient serum and Cu-deficient embryos cultured in control serum also showed abnormal development, but to a lesser degree than that of the Cu-deficient embryos cultured in Cu-deficient serum. To test the idea that the above abnormalities were due in part to free radical induced damage occurring secondary to an impaired oxidant defense system, a chemiluminescence assay was used to detect superoxide dismutase (SOD) activity in the cultured embryos. SOD activity was lowest in embryos cultured in Cu-deficient serum. When the Cu-deficient serum was supplemented with antioxidants (CuZnSOD or glutathione peroxidase), its teratogenicity was reduced. These data support the idea that an impaired oxidant defense system contributes to the dysmorphology associated with Cu deficiency. However, the Cu-deficient embryos also had low cytochrome c oxidase activity compared to control embryos--thus, multiple factors are likely contributing to Cu deficiency-induced abnormalities.

Marked and rapid decreases of circulating leptin in streptozotocin diabetic rats: reversal by insulin.

Evidence for regulation of circulating leptin by insulin is conflicting. Diabetes was induced in rats with streptozotocin (STZ; 40 mg.kg(-1).day(-1) x 2 days) to examine the effect of insulin-deficient diabetes and insulin treatment on circulating leptin. After 12 wk, plasma leptin concentrations in untreated rats were all < 0.4 ng/ml versus 4.9 +/- 0.9 ng/ml in control animals (P < 0.005). In rats treated with subcutaneous insulin implants for 12 wk, which reduced hyperglycemia by approximately 50%, plasma leptin was 2.1 +/- 0.6 ng/ml, whereas leptin concentrations were 6.0 +/- 1.6 ng/ml in insulin-implanted rats receiving supplemental injections of insulin for 4 days to normalize plasma glucose (P < 0.005 vs. STZ untreated). In a second experiment, plasma leptin was monitored at biweekly intervals during 12 wk of diabetes. In rats treated with insulin implants, plasma leptin concentrations were inversely proportional to glycemia (r = -0.64; P < 0.0001) and unrelated to body weight (P = 0.40). In a third experiment, plasma leptin concentrations were examined very early after the induction of diabetes. Within 24 h after STZ injection, plasma insulin decreased from 480 +/- 30 to 130 +/- 10 pM (P < 0.0001), plasma glucose increased from 7.0 +/- 0.2 to 24.8 +/- 0.5 mM, and plasma leptin decreased from 3.2 +/- 0.2 to 1.2 +/- 0.1 ng/ml (delta = -63 +/- 3%, P < 0.0001). In a subset of diabetic rats treated with insulin for 2 days, glucose decreased to 11.7 +/- 3.9 mM and leptin increased from 0.5 +/- 0.1 to 2.9 +/- 0.6 ng/ml (P < 0.01) without an effect on epididymal fat weight. The change of leptin was correlated with the degree of glucose lowering (r = 0.75, P < 0.05). Thus insulin-deficient diabetes produces rapid and sustained decreases of leptin that are not solely dependent on weight loss, whereas insulin treatment reverses the hypoleptinemia. We hypothesize that decreased glucose transport into adipose tissue may contribute to decreased leptin production in insulin-deficient diabetes.