Effect of dietary caffeine and zinc on the activity of antioxidant enzymes,zinc, and copper concentration of the heart and liver in fast-growing rats

The purpose of this study was to determine the relationship between concentrations of Zn and Cu and the activities of superoxide dismutase and glutathione peroxidase in the heart and liver of young rat pups whose dams were fed a diet supplemented with caffeine and/or Zn. Four groups of dams with their newborn pups were fed one of the following diets for 22 d: 20% protein basal diet; the basal diet supplemented with caffeine (2 mg/100 body wt); the basal diet supplemented with Zn (300 mg/kg diet); or the basal diet supplemented with caffeine plus Zn. The Cu levels in the livers of the pups were decreased by maternal intake of the caffeine and Zn diet. The maternal intake of the caffeine diet increased Mn-superoxide dismutase (MnSOD) activity and Cu, Zn-superoxide dismutase (CUZnSOD) in the heart of the pups. On the other hand, the activity of Cu,ZnSOD was significantly reduced in the liver of pups whose dams consumed a caffeine, Zn, or caffeine plus Zn diet. Cu, ZnSOD activity in the liver of the pups seems to be correlated with Cu levels in the tissue. Selenium-dependent glutathione peroxidase (GSH-Px) activities in the heart and liver showed no difference among the groups. The effect of dietary caffeine and/or Zn on the activity of antioxidant enzymes in the heart and liver were different in young rats. The activities of these enzymes in the heart were lower than in the liver of 22-d-old rats. Our experiments indicate that the heart has limited defenses against the toxic effects of peroxides when compared to the liver.     

Regulation of the ontogeny of rat liver metallothionein mRNA by zinc

To investigate the role of metals in the regulation of the ontogenic expression of rat liver metallothionein (MT) mRNA, the concentrations of zinc, MT and MT mRNA were determined in livers of fetal and newborn rats from dams which were fed with a control or zinc-deficient or copper-deficient or iron-deficient diet from day 12 of gestation. The liver samples were analyzed for MT-mRNA levels using a mouse MT-I cRNA probe. Although the newborn hepatic levels of each metal (zinc or copper or iron) was specifically reduced corresponding to the respective mineral deficiencies, the hepatic concentrations of total MT and MT-I mRNA were significantly decreased only in pups born from zinc-deficient dams. Injection of the zinc-deficient newborn pups with 20 mg Zn as ZnSO4/kg restored with MT-I mRNA levels to slightly above control values within 5 h of injection. The hepatic zinc, MT and MT-I mRNA levels were observed to increase significantly in control fetal rat liver on days 17-21 of gestation but there were little changes in either zinc or MT in fetal livers from zinc-deficient dams during the late gestational period. The MT-I mRNA level also did not show an increase on days 18 and 20 of gestation in zinc-deficient fetal liver as compared to controls. These results demonstrate a direct role of zinc in hepatic MT gene expression in rat liver during late gestation. Immunohistochemical localization of MT using a specific antibody to rat liver MT showed that the staining for MT in zinc-deficient pup liver was mainly in the cytosol in contrast to the significant nuclear MT staining observed in control newborn rat liver. The results suggest that maternal zinc deficiency has a marked effect not only in decreasing the levels of hepatic MT and MT-I mRNA but also in the localization of MT in newborn rat liver.     

Gestational zinc deficiency amplifies the regulation of metallothionein induction in adult mice

To determine if prenatal zinc deficiency has a persistent effect on metallothionein (MT) regulation, Swiss-Webster mice were mated and fed a diet containing either control (100 micrograms Zn/g) or low levels of zinc (5 micrograms Zn/g) from Day 7 of gestation to parturition. After birth all mice were given the control diet. Liver zinc and MT levels were 50% lower in newborn pups from dams fed the low zinc diets than in control pups. In control pups, liver zinc and MT concentrations were relatively stable during the first week of postnatal life. In contrast, in pups prenatally deprived of zinc, liver levels of zinc and MT increased such that by Day 3 of postnatal life, the levels were not significantly different from controls. At Day 56, serum IgM concentrations were significantly lower in the low zinc offspring. Liver zinc concentrations in the two groups of mice were similar at Day 70 postnatal, and in both groups liver MT levels were below detection limits. However, when Day 70 mice were given zinc injections to stimulate MT synthesis, the prenatally zinc deprived offspring showed markedly higher liver MT levels than did control mice given similar injections, despite similar liver zinc concentrations in the two groups. These results show that prenatal zinc deficiency has pronounced effects on postnatal MT metabolism which can persist into adulthood.     

Effects of marginal zinc deficiency on microtubule polymerization in the developing rat brain

One of the possible mechanisms that has been proposed to underlie the deleterious effects of zinc deficiency on brain development is an impairment in the normal formation of the cytoskeletal network. In the current study, in vivo microtubule polymerization was characterized in brain supernatant fluids, from 20-d-old pups whose dams were fed diets containing control (50 micrograms zinc/g) or marginal levels of zinc (10 micrograms zinc/g) throughout pregnancy and lactation. Pup brain and body weights were similar between the groups; however, plasma zinc concentrations were lower (27%) in pups fed the marginal zinc diet than in controls. Tubulin concentrations in 100,000 g brain supernates were similar between the groups; however, tubulin polymerization in the brain supernates was significantly lower in pups fed the marginal zinc diet compared to controls. Primarily, the early events of polymerization were affected; the lag period of the reaction was doubled, and the initial velocity was slower (26%) in supernates from pups fed the marginal zinc diet than in controls. These findings support the idea that some of the negative effects of marginal zinc deficiency on brain development and function may be mediated by an alteration in microtubule formation.     

Postnatal essential fatty acid deficiency in mice affects lipoproteins, hepatic lipids, fatty acids and mRNA expression

We have previously reported that essential fatty acid deficiency (EFAD) during suckling in mice resulted in an adult lean phenotype and a resistance to diet-induced obesity. We now hypothesized that postnatal EFAD would cause long-term effects on lipid metabolism. C57BL/6 mice were fed an EFAD or a control diet from the 16th day of gestation and throughout lactation. The pups were weaned to standard diet (STD) and at 15 weeks of age given either high fat diet (HFD) or STD. Lipoprotein profiles, hepatic lipids, fatty acids and mRNA expression were analyzed in 3-week-old and 25-week-old offspring. At weaning, the EFAD pups had higher cholesterol levels in both plasma and liver and 6-fold higher concentrations of hepatic cholesterol esters than control pups. Adult EFAD offspring had higher levels of hepatic cholesterol and linoleic acid, but lower levels of dihomo-γ-linolenic acid and Pparg mRNA expression in the liver. In addition, HFD fed EFAD offspring had lower plasma total cholesterol, lower hepatic triglycerides and lower liver weight compared to controls fed HFD. In conclusion, early postnatal EFAD resulted in short-term alterations with increased hepatic cholesterol accumulation and long-term protection against diet-induced liver steatosis and hypercholesterolemia.     

Hepatic insulin binding following in utero exposure to ethanol

Insulin binding to liver membranes has been studied in term fetuses of rats fed ethanol-containing liquid diet during pregnancy . Pair-fed and ad libitum-fed controls received liquid diet in which maltose-dextrins were substituted isocalorically for ethanol. Food consumption and body weigh gain of ethanol- imbibing dams were 35% and 70% less than their ad libitum counterparts respectively. Ethanol-fed rats also exhibited less gain in body weight than pair-fed controls despite isocalorically equivalent food intake. The number of live pups was not different among the various groups; however, liver weight of fetuses exposed to ethanol in utero was 47% less than those of the pups of ad libitum control dams and 28% less than those of the offspring of pair-fed control rats. Insulin binding to liver membranes of fetuses exposed to ethanol in utero was lower than that of ad libitum controls but was not significantly different from that of the pair-fed control animals. Average affinity profiles showed a reduction in K at all levels of receptor occupancy in the fetuses of ethanol-fed rats. For fetuses of the pair-fed group, K was reduced only at fractional occupancy below 20% but not at higher fractional occupancy. Because of the similarity of insulin binding in the fetuses of the ethanol-fed rats and their pair-fed counterparts, effects of ethanol on insulin binding cannot account for the reduced hepatic glycogen stores previously reported in term fetuses.     

Maternal zinc deficiency reduces NMDA receptor expression in neonatal rat brain, which persists into early adulthood

Prenatal and early postnatal zinc deficiency impairs learning and memory and these deficits persist into adulthood. A key modulator in this process may be the NMDA receptor; however, effects of zinc deficiency on the regulation of NMDA receptor activity are not well understood. Female Sprague-Dawley rats were fed diets containing 7 (zinc deficient, ZD), 10 (marginally zinc deficient, MZD) or 25 (control) mg Zn/g diet preconception through postnatal day (PN) 20, at which time pups were weaned onto their maternal or control diet. Regulation of NMDA receptor expression was examined at PN2, PN11, and PN65. At PN2, expression of whole brain NMDA receptor subunits NR1, NR2A, and NR2B was lower in pups from dams fed ZD and MZD compared to controls, as analyzed using relative RT-PCR and immunoblotting. At PN11, whole brain and hippocampi NR1, NR2A, NR2B and PSA-NCAM (polysialic acid-neural cell adhesion molecule) expression and the number of PSA-NCAM immunoreactive cells were lower in pups from dams fed ZD compared to controls. Whole brain brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) concentrations were lower in pups from dams fed ZD or both low zinc diets, respectively. Whole brain NR1 expression remained lower in previously zinc-deficient rats at PN65. These data indicate potential mechanisms through which developmental zinc deficiency can impair learning and memory later in life.     

The effect of late prenatal and/or early postnatal zinc deficiency on the development and some biochemical aspects of the cerebellum and hippocampus in rats

In rats, late prenatal and/or early postnatal zinc deficiency results in behavioural anomalies in adult animals, but not in overt dysmorphogenesis of the central nervous system. Cerebellar and hippocampal development occurs mainly in the first three weeks postnatally and zinc accumulates specifically in the mossy fibres of the hippocampus during this period.In the present investigation, rat pups were suckled by dams fed a zinc-deficient (<0.5 mg/kg) diet either from day 19 of pregnancy or from parturition. Control animals were restricted-fed the same diet supplemented with 100 mg zinc/kg. Studies were performed on pups either on day 18 postpartum in the case of animals fed the experimental diets from parturition, or on day 20 for pups which received treatment from day 19 of gestation.Cerebellar and hippocampal weights were lower in pups suckling from zinc-deficient dams but zinc levels were not affected in either organ, although histological evidence suggested less zinc in the hippocampal mossy fibres. Incorporation of H-thymidine into cerebellar and hippocampal DNA was not affected by maternal zinc status, nor was the activity of the zinc metalloenzyme alkaline phosphatase.The activity of the myelin-marker enzyme 2′, 3′-cyclic nucleotide 3′-phosphohydrolase was substantially lower in both regions of the brain in zinc deprived pups, especially in the hippocampus. Activity of the zinc metalloenzyme L-glutamic acid dehydrogenase was also diminished in both tissues from 20-day-old pups and in the hippocampi of 18-day-old animals.The data suggest that cerebellar and hippocampal DNA synthesis is not seriously affected by late prenatal and/or early postnatal zinc depletion, but that the activities of two enzymes associated with neural function are. The possibility is raised that these defects may be associated with the behavioural changes observed in rats subjected to zinc impoverishment during the period of maximal cerebellar and the hippocampal development.     

Augmented resistance to oxidative stress in fatty rat livers induced by a short-term sucrose-rich diet

Hepatic steatosis and the accompanying oxidative stress have been associated with a variety of liver diseases. It is not known if fat accumulation per se plays a direct role in the oxidative stress of the organ. This study tested if steatosis induced by a short-term carbohydrate-rich diet results in an increased hepatic sensitivity to oxidative stress. Antioxidant status was determined in a liver perfusion system and in isolated parenchymal, endothelial and Kupffer cells from rats kept on sucrose-rich diet or on regular diet for 48 h. t-Butyl hydroperoxide addition (2 mM) to the perfusion fluid resulted in a release of alanine aminotransferase (ALT) in livers from controls, whereas no ALT release was observed in fatty livers. After t-butyl hydroperoxide addition, oxidized glutathione release was 40% less in fatty than in control livers, whereas reduced glutathione (GSH) release was not different. Sinusoidal oxidant stress was mimicked by the addition of lipopolysaccharide (LPS) from Escherichia coli (10 microg/ml) followed by the addition of opsonized zymosan (8 mg/ml) to the perfusion medium. LPS plus zymosan treatments resulted in the release of ALT in control but not in fatty livers. At the end of perfusion, liver glutathione content was 3-fold elevated, and the tissue content of lipid peroxidation products was approx. 40% less in fatty livers compared to controls. GSH content was doubled and glucose-6-phosphate dehydrogenase (G6PD) expression was elevated by 3- and 10-fold in sinusoidal endothelial and parenchymal cells form fatty livers compared to cells from control animals. Following H(2)O(2) administration in vitro (0.2-1 mM), GSH remained elevated in endothelial and parenchymal cells from fatty livers compared to cells from controls. In contrast, G6PD activity and GSH content were similar in Kupffer cells isolated from fatty or control livers. The study shows that hepatic fat accumulation caused by a short-term sucrose diet is not accompanied by elevated hepatic lipid peroxidation, and an elevated hepatic antioxidant activity can be manifested in the presence of prominent steatosis. The diet-induced increase in G6PD expression and, thus, the efficient maintenance of reduced glutathione in endothelial and parenchymal cells are a supportive mechanism in the observed hepatic resistance against intracellular or sinusoidal oxidative stress.     

Maternal essential fatty acid deficiency depresses serum leptin levels in suckling rat pups

Dietary lipid quantity and quality have recently been shown to affect serum leptin levels in adult rats. Moreover, suckling pups from dams fed a high fat diet had increased serum leptin levels. The aim of the present study was to analyze the influence of essential fatty acid (EFA) deficiency on serum leptin levels in dams and their pups during the suckling period. For the last 10 days of gestation and throughout lactation, pregnant rats were fed a control or an EFA-deficient (EFAD) diet. The levels of leptin and EFA in the serum of the dams and pups were analyzed 1, 2, and 3 weeks after delivery. In parallel, serum levels of glucose and corticosterone were analyzed in the pups. Low serum leptin levels were found in the control lactating dams during the entire lactation period compared with the age-matched nonlactating animals. The leptin concentrations in the lactating dams fed the EFAD diet were lower compared with those fed the control diet. The serum leptin levels of suckling pups from dams on the EFAD diet were markedly decreased compared with controls (P < 0.05). The reduced serum leptin levels could not be explained by nutritional restriction as evaluated by serum levels of glucose and corticosterone. These results indicate the importance of the EFA composition of the maternal diet for serum leptin levels in both dams and pups. EFA deficiency in lactating dams may cause long-term effects on the pups through dysregulation of leptin and leptin-dependent functions. -- Korotkova, M., B. Gabrielsson, L. A. Hanson, and B. Strandvik. Maternal essential fatty acid deficiency depresses serum leptin levels in suckling rat pups. J. Lipid Res. 2001. 42: 359--365.     

Effects of antenatal,postpartum and post-weaning melatonin supplementation on blood pressure and renal antioxidant enzyme activities in spontaneously hypertensive rats

Although melatonin lowers blood pressure in spontaneously hypertensive rats (SHR), its effect following antenatal and postpartum supplementation on the subsequent development of hypertension in SHR pups remains unknown. To investigate this, SHR dams were given melatonin in drinking water (10 mg/kg body weight/day) from day 1 of pregnancy until day 21 postpartum. After weaning, a group of male pups continued to receive melatonin till the age of 16 weeks (Mel-SHR), while no further melatonin was given to another group of male pups (Maternal-Mel-SHR). Controls received plain drinking water. Systolic blood pressure (SBP) was measured at 4, 6, 8, 12 and 16 weeks of age, after which the kidneys were collected for analysis of antioxidant enzyme profiles. SBP was significantly lower till the age of 8 weeks in Maternal-Mel-SHR and Mel-SHR than that in the controls, after which no significant difference was evident in SBP between the controls and Maternal-Mel-SHR. SBP in Mel-SHR was lower than that in controls and Maternal-Mel-SHR at 12 and 16 weeks of age. Renal glutathione peroxidase (GPx) and glutathione s-transferase (GST) activities, levels of total glutathione and relative GPx-1 protein were significantly higher in Mel-SHR. GPx protein was however significantly higher in Mel-SHR. No significant differences were evident between the three groups in the activities of superoxide dismutase, catalase and glutathione reductase. In conclusion, it appears that while antenatal and postpartum melatonin supplementation decreases the rate of rise in blood pressure in SHR offspring, it however does not alter the tendency of offspring of SHR to develop hypertension.     

Effect of zinc deficiency and supplementation on lipid peroxidation of renal tissue in ovariectomized rats

The aim of this study was to investigate how zinc deficiency and supplementation affects lipid peroxidation in the renal tissue in ovariectomized rats. Four study groups were formed with 10 Spraque-Dawley rats each. Two of the groups served as normal and ovariectomized controls; the other two were ovariectomized rats that were zinc deficient and zinc supplemented, respectively. The zinc-deficient ovariectomized rats showed greater renal and plasma lipid peroxidation, as indicated by higher malondialdehyde levels than all other groups (p<0.05). These values were higher in the ovariectomized controls than those of the normal controls and of the ovariectomized, zinc-supplemented groups (p<0.05), which, in, turn, showed no significant differences of their respective renal and plasma malondialdehyde values. The renal and erythrocyte glutathione levels in the zinc-supplemented rats were higher than those in all other groups (p<0.05). The zinc-deficient group had the lowest renal and erythrocyte glutathione levels (p<0.05). The renal tissue zinc levels in the ovariectomized rats were higher than those in the zinc-deficient animals, but lower than in the normal controls and zincsupplemented rats (p<0.05). The zinc-supplemented animals had the highest renal tissue zinc levels (p<0.05). The results of this study suggest that zinc deficiency increases renal tissue damage in ovariectomized rats and that zinc supplementation can be used to prevent this condition.     

Zinc,ethanol, and lipid peroxidation in adult and fetal rats

Studies were performed on adult and fetal rats receiving either a zinc-deficient (<0.5 ppm) diet and/or ethanol (20%) throughout pregnancy. Liver zinc levels were depressed in fetuses exposed toin utero zinc deficiency, but brain zinc levels were unchanged. Ethanol had no effect on the concentration of zinc in the several fetal and adult tissues studies. Lipid peroxidation, as measured by endogenous levels of malondialdehyde (MDA) increased following food restriction, zinc improverishment, and alcoholism in adult and fetal livers, but not in fetal brains. Generally, levels of MDA were highest when both zinc deficiency and the ingestion of alcohol occurred concurrently. Glutathione (GSH) was depressed by zinc restriction in several adult and fetal tissues, but not in the fetal brain. Ethanol alone had no effect on GSH levels. The activity of the enzyme glutathione peroxidase (GSH-Px) was not changed in either organism by alcohol or zinc deficiency. Overall, the data point to increased lipid peroxidation in maternal and fetal rat tissues following zinc depletion and/or treatment with alcohol and draw attention to the apparent vulnerability of the fetal liver toin utero alcoholism. By contrast, the fetal brain seems to be especially resistant to alcohol and zinc-related lipoperoxidation. An association is suggested between the increased lipoperoxidation accompanying zinc deficiency and reduced levels of GSH, but this does not appear to relate to changes in the activity of GSH-Px. A similar relationship is not evident with respect to the increased levels of MDA in fetal and adult livers following chronic alcohol intoxication. A possible basis for the zinc-GSH interaction is discussed.     

Low-protein diet changes thyroid function in lactating rats

Lactating rats were fed with free access to an 8% protein-restricted diet (PR); the control group was fed a 23% protein diet (C). An energy-restricted (pair-fed) group was given the same food as the animals in the control group, but the amounts of food consumed by both PF and PR were about the same. The body weight and serum albumin concentration of PR and PF dams were significantly (P < 0. 05) lower than that of the controls. The PR group had a significant increase in serum-free triiodothyronine (FT3) concentration, 24-hr mammary gland and milk radioiodine (I131) uptake (67%, 278%, and 200%, respectively) as compared with the controls. On the other hand, those animals had a significantly lower serum-free thyroxine (FT4) concentration and 2- and 24-hr thyroid I131 uptake (67%, 64%, and 74%, respectively). Protein malnutrition during lactation did not alter thyroid or liver 5'-deiodinase activity significantly. However, PF dams had a significantly lower (25%) thyroid 5'-deiodinase activity. These data suggest that protein-restricted lactating dams had an adaptive change in the thyroid function, which could be important to increase the transference of iodine or triiodothyronine through the milk to their pups and prevent sequelae of neonatal hypothyroidism.     

Maternal treatment with oleoyl-estrone induces resistance to lipid accrual in their descendants

Objective: To determine whether treatment of rat dams with oleoyl‐estrone (OE) has an effect on the offspring's long‐term response to diet restriction during lactation. Methods and Procedures: Control, OE‐treated, and diet‐restricted dams were treated up to day 15 of lactation. Changes in food intake and body weight were recorded for dams and their pups. After weaning, pups received a 4‐week standard diet followed by a 4‐week period of high‐fat diet. Lipid, protein, and energy content of pups plus energy intake and efficiency. Serum metabolites (glucose, urea, and cholesterol) and serum hormones (adiponectin, leptin, insulin, and sexual hormones). Results: Neither pups from dams in the OE‐treated nor in the diet‐restricted group showed significant changes in weight, though these two groups ingested 79% of food ingested by controls. At weaning, the pups from OE‐treated rats were smaller than those of the control or diet‐restricted groups. These pups maintained the differences in size and lipid content during the 4‐week standard‐diet period, whereas pups from diet‐restricted dams showed a sharp decrease in their lipid content. During the 4 weeks of high‐fat diet, the male offspring from OE‐treated dams increased the difference in lipid content in relation to the pups from control dams whereas in females the differences decreased. Female offspring from diet‐restricted dams showed the most marked changes in metabolite and hormone levels in relation to controls. Discussion: Treatment of lactating dams with OE programs the metabolic response of their offspring to resist the challenge of a high‐fat diet that would lead to obesity in adulthood.     

Glutathione depletion by hyperphagia-induced obesity

Reduced glutathione (GSH) levels in freeze-clamped livers of rats and mice in which hyperphagia is induced by cafeteria diet are 45% lower than in controls. Freshly isolated hepatocytes from mice fed cafeteria diet show a 45% decrease in GSH concentration and a 54% decrease in oxidized glutathione (GSSG) concentration when compared with controls. The rate of GSH synthesis in isolated hepatocytes from control mice is significantly higher than in those from mice fed cafeteria diet. Oral GSH is effective to prevent the decrease in hepatic GSH levels found in cafeteria fed mice.     

Effects of dietary zinc deficiency on homocysteine and folate metabolism in rats

In rats, zinc deficiency has been reported to result in elevated hepatic methionine synthase activity and alterations in folate metabolism. We investigated the effect of zinc deficiency on plasma homocysteine concentrations and the distribution of hepatic folates. Weanling male rats were fed ad libitum a zinc-sufficient control diet (382.0 nmol zinc/g diet), a low-zinc diet (7.5 nmol zinc/g diet), or a control diet pair-fed to the intake of the zinc-deficient rats. After 6 weeks, the body weights of the zinc-deficient and pair-fed control groups were lower than those of controls, and plasma zinc concentrations were lowest in the zinc-deficient group. Plasma homocysteine concentrations in the zinc-deficient group (2.3 +/- 0.2 micromol/L) were significantly lower than those in the ad libitum-fed and pair-fed control groups (6.7 +/- 0.5 and 3.2 +/- 0.4 micromol/L, respectively). Hepatic methionine synthase activity in the zinc-deficient group was higher than in the other two groups. Low mean percentage of 5-methyltetrahydrofolate in total hepatic folates and low plasma folate concentration were observed in the zinc-deficient group compared with the ad libitum-fed and pair-fed control groups. The reduced plasma homocysteine and folate concentrations and reduced percentage of hepatic 5-methyltetrahydrofolate are probably secondary to the increased activity of hepatic methionine synthase in zinc deficiency.     

Effects of chronic lead and cadmium exposure on blood pressure in occupationally exposed workers

Studies were carried out to determine the effect of dietary vanadium on chicks fed phosphorus deficient and control diets. Vanadium at 50 mg/kg of diet decreased growth of both control and deficient chicks. The high mortality among the phosphorus deficient chicks was significantly alleviated by the presence of vanadium. The increased relative ventricular weights found among the deficient chicks was also alleviated by the presence of dietary vanadium. Vanadium fed at 10 or 20 mg/kg diet did not reduce growth rate but significantly reduced mortality among chicks fed the deficient diet and decreased the relative ventricle weights. Time course studies revealed that chicks are hatched with high relative ventricular weights (.83% of body wt) and remain at that level among chicks fed the phosphorus deficient diet. The addition of vanadium or phosphate to the diet resulted in a progressive decrease in relative ventricular weights. The inclusion of vanadium in the diet resulted in increased serum phosphorus levels among the deficient chicks that may be related to the decrease in mortality and relative ventricle weights.