Effect of fasting on the composition of plasma lipoproteins in cholesterol-fed diabetic rabbits

Cholesterol-fat feeding is associated with unusual alterations in the composition of plasma lipoproteins in alloxan-diabetic rabbits. In the present study plasma lipoprotein lipid and apoprotein composition was studied before and after 48 hr of fasting in cholesterol-fed diabetic and control rabbits in order to further characterize these alterations. Compared with control rabbits, the diabetic rabbits had similar plasma cholesterol levels, but 100-fold higher triglyceride levels prior to fasting. These plasma lipids were distributed mainly to large, Sf greater than 400 plasma lipoproteins in the diabetic rabbits, and to beta-VLDL in control rabbits. Sf greater than 400 lipoproteins, VLDL, IDL, LDL, and HDL from diabetic rabbits had triglyceride as the predominant lipoprotein core lipid. Sf greater than 400 lipoproteins and VLDL from diabetic rabbits had lesser amount of apoprotein E, and greater amounts of apoproteins A-I, A-IV, and B-48 as percent of total apoprotein mass in comparison with control rabbits. Fasting reduced plasma triglyceride levels by 55% in diabetic rabbits. Sf greater than 400 lipoprotein and VLDL triglyceride content decreased but remained a major core lipid. Fasting eliminated apoproteins A-I and A-IV from Sf greater than 400 lipoproteins and VLDL, but had no significant effect on apoB-48 content. Insulin treatment of the diabetic rabbits reduced plasma triglyceride by approximately 90% resulting in cholesteryl ester-rich particles reassembling beta-VLDL both in the Sf greater than 400 lipoprotein and VLDL fractions. These results indicate that the alterations in plasma lipoproteins in cholesterol-fed diabetic rabbits result from the presence in the d less than 1.006 g/ml plasma lipoprotein class of partially metabolized, intestinally derived particles.     

Effect of recombinant human interleukin-11 on motilin and substance P release in normal and inflamed rabbits

Recombinant human interleukin-11 (rhIL-11) normalizes depressed smooth muscle tension generation towards motilin and substance P (SP) in rabbits with colitis. The aim of this paper was to evaluate the effect of rhIL-11 treatment on motilin and SP release which could have an effect on the contractility changes. Rabbits received 4, 40, 72 or 720 microg/kg rhIL-11 s.c. or saline, 1 h later a continuous s.c. administration of rhIL-11 was started with or without the induction of colitis (135 mg/kg TNBS) for 5 days. Motilin and SP levels were measured by RIA, motilin mRNA expression by RT-PCR. TNBS-colitis did not affect plasma motilin levels but increased the motilin content of the duodenal mucosa 1.7-fold. rhIL-11 treatment dose-dependently increased plasma motilin levels (720 microg/kg day: 3.5-fold) and the motilin content of the duodenal mucosa (720 microg/kg day: 3.0-fold). The effects of rhIL-11 were similar in normal rabbits and were accompanied by an increased motilin mRNA expression. TNBS-colitis decreased plasma SP levels 2.7-fold and the SP content in the colonic muscle layer 7.1-fold. The decrease in the muscle layer, but not in the plasma, was normalized by rhIL-11 treatment. In normal rabbits, rhIL-11 caused a decrease in plasma SP levels, but had no effect on the tissue content of SP. In conclusion, treatment of inflamed or normal rabbits with rhIL-11 increases plasma and tissue levels of motilin in the duodenal mucosa via an increased expression of motilin in the endocrine cells and induces the release of SP from extrinsic neurons. These changes do not explain the beneficial effect of rhIL-11 on the lowered contractility in inflamed rabbits although a change in balance of neuropeptides may influence gastro-intestinal inflammation.     

The thyroid and adrenal glands in rats chronically exposed to an intense electric field

Two month-old male Long-Evans rats were exposed for 8 hours a day during 4 weeks to an ambient electric field (50 kV/m). The growth rate of electric field-exposed rats was identical to the controls' one. No significant effect of exposure was observed on the levels of various hormones: plasma and adrenal corticosterone; plasma TSH, ACTH, T3 and T4; adrenal epinephrine and norepinephrine. Histological studies of thyro?d and adrenals showed a normal appearance. In adrenals, the levels of various components and the activities of enzymes which have a role on stero?dogenesis were not modified. It is concluded that, in the present experiment conditions, the daily exposure of the rat to a severe electric field does not affect the normal state of thyro?d and adrenals.     

Development of young rats and rabbits exposed to a strong electric field

Body growth and circulating levels of hormones were assessed in young rats and rabbits exposed to a 50-Hz electric field of 50 kV/m. Eight-week-old male rats were exposed 8 h/day for 4 weeks and rabbits were exposed 16 h/day from the last 2 weeks of gestation to 6 weeks after birth. The body and the organ growth of exposed rats were not statistically different from those of sham-exposed controls. No important differences from controls were observed in plasma levels of corticosterone, TSH, ACTH, and T4 or in adrenal levels of epinephrine, norepinephrine, and corticosterone although T3 was slightly, but significantly, decreased. No large histological changes in the thyroid or adrenals were noted. In rabbits, organ and body weights of exposed animals were comparable to those of controls. Plasma levels of various hormones (ACTH, GH, T3, T4, corticosterone, cortisol), serum glucose, triglycerides, and cholesterol were not significantly altered. Adrenal content of cortisol was lower, however, in exposed rabbits. No histological changes of the thyroid or adrenal glands were observed.     

Biological characteristics of peptidoglycans of group A streptococcus and some other bacterial species. I. Tolerance and effect of antibody in fever response, and heart damaging effect in rabbits.

Induced tolerance to the pyrogenic action of group A streptococcus peptidoglycan decreased after one week and was no longer detectable after the second week. However, one or two further doses of peptidoglycan rapidly restored the tolerance. The passive transfer of plasma from rabbits tolerant to streptococcus peptidoglycan to nontolerant animals failed to transfer tolerance. Antiserum to streptococcus peptidoglycan neutralized the pyrogenic effect of not only streptococcus but also staphylococcus and pneumococcus peptidoglycan; it did not influence the febrile response to endotoxin. Histopathologic changes in the rabbit heart produced by the intravenous injection of staphylococcus or pneumococcus peptidoglycans were similar and were characterized by various stages of degeneration and necrosis. The changes were less pronounced than after streptococcus peptidoglycan. Antiserum to streptococcus peptidoglycan had modest or no counteracting effect on the development of heart alterations after staphylococcus or pneumococcus peptidoglycan.     

Long-term effects of partial ileal bypass on the health status of rabbits

Partial ileal bypass (PIB) surgery is a method for the treatment of familial hypercholesterolaemia in man. Since the rabbit is frequently used as an animal model in experimental studies on PIB, we have investigated the long-term effects of this surgical procedure on the health status of rabbits. Forty-eight weeks after surgery plasma and liver cholesterol levels were decreased by about 40%. The inner diameter of the bypassed ileum was drastically reduced, unlike its length. The bypassed segment did not show clear histological abnormalities. The microflora of the caecum was similar in control and PIB rabbits. PIB did not influence liver histology. The bile of the rabbits with PIB was less lithogenic than that of control animals. Blood haemoglobin levels, haematocrit values and plasma concentrations of alkaline phosphatase, alanine aminotransferase, gamma-glutamyl transferase and lactate dehydrogenase were not changed after PIB. Plasma levels of albumin, creatinine, calcium, phosphorus, vitamin B12 and folic acid were not significantly affected by PIB. Rabbits with PIB had significantly higher plasma levels of bilirubin and zinc than control rabbits, but plasma vitamin E concentrations were significantly lower. These results may be of importance for further studies on the effects of PIB in rabbits.     

Role of glucocorticoids in the stress-induced suppression of testicular steroidogenesis in adult male rats.

We have examined the role of glucocorticoids in the stress-induced inhibition of testicular steroidogenesis. Immobilization (3 hr) reduced plasma testosterone (T) levels to 24% of control values but did not affect plasma LH levels. This reduction was partially reversed by in vivo injections of the antiglucocorticoid, RU486, prior to the stress session at a dose of 10 mg/kg BW, but not at 1.0 or 50 mg/kg BW. Stressed rats that were treated with 10 mg/kg BW RU486 had twofold higher plasma T levels than vehicle-treated stressed animals. Injections of RU486 did not affect plasma LH levels in control or stressed rats and did not affect T levels of unstressed rats. Stressed rats had eightfold higher plasma corticosterone levels than controls, and RU486 had no effect on control or stress levels of corticosterone. The possible role of glucocorticoids in mediating the effect of stress on testicular T production was investigated also in vitro by incubating testicular interstitial cells from unstressed rats for 3 hr with corticosterone (0, 0.01, 0.1, or 1.0 microM) or dexamethasone (0, 0.001, 0.01, or 0.1 microM), followed by an additional 2 hr with hCG (0, 25, 50, or 100 microIU). Both corticosterone and dexamethasone inhibited hCG-stimulated T production in a dose-dependent manner. Cells incubated with the highest concentration of either of the glucocorticoids showed significantly reduced responses to hCG stimulation. In the absence of hCG, in vitro T production was not affected by dexamethasone or 0.01 and 0.1 microM corticosterone. However, the highest dose of corticosterone (1.0 microM) produced a 63% elevation in basal T production. Coincubation of testicular interstitial cells with corticosterone (1.0 microM) or dexamethasone (0.1 microM) and RU486 (0.01, 0.1, and 1.0 microM) reversed the glucocorticoid-induced suppressions of T production in a dose-dependent manner. Our results suggest that during stress increases in plasma levels of glucocorticoids in male rats act via glucocorticoid receptors on testicular interstitial cells to suppress the testicular response to gonadotropins, and that the decline of testosterone production during immobilization stress is in part mediated by a direct action of glucocorticoids on the testis.     

Effect of Ambient Salinity,Food-deprivation and Prolactin on the Thyroidal Response to TSH,and in vitro Hepatic T4 to T3 Conversion in Yearling Coho Salmon,Oncorhynchus kisutch

This study examines the effect of food deprivation, increased ambient salinity and prolactin administration on the thyroidal response to ovine TSH, and in vitro hepatic monodeiodination of T4 to T3 in coho salmon, Oncorhynchus kisutch. Fed fish and fish food-deprived for 18 days showed similar significant increases in plasma T4 9 and 24 h after a single injection of TSH. Plasma T3 levels were also elevated in both fed and food-deprived fish 9 h after the TSH injection but plasma T3 levels in the food-deprived fish were markedly lower than in the fed salmon. The increase in T4 and T3 evident in freshwater-acclimated fish after TSH administration was not found in salmon acclimated to 65% sea water. Prolactin, given alone (either as a single injection or a series of three daily injections) had no effect on plasma T4 or T3 levels. When given together with TSH prolactin prolonged the T4 and T3 elevating effect of TSH. Food-deprived salmon had lower in vitro hepatic T4 to T3 conversion rates than fed groups but T4 to T3 conversion did not appear to be affected by increased ambient salinity, or by prolactin and/or TSH administration.     

The decrease in plasma melatonin at metamorphic climax in Rana catesbeiana (bullfrog) tadpoles is induced by thyroxine.

Melatonin decreases in the plasma of Rana catesbeiana (bullfrog) tadpoles at the climax of metamorphosis when the thyroxine (T(4)) level peaks. Since melatonin inhibited thyroid function in vitro, it would be of interest to determine if the decline in plasma melatonin permits greater thyroid hormone secretion, or if the increasing levels of T(4) cause the climactic decrease in plasma melatonin. The reciprocal effects of administering T(4) or melatonin just prior to metamorphic climax were examined in tadpoles kept at 22 degrees C on an 18L:6D cycle. If melatonin functions as a thyroid antagonist at later metamorphic stages, administration of melatonin should decrease plasma T(4), whereas if T(4) causes the decline in plasma melatonin, T(4) treatment of tadpoles prior to climax should induce the climactic melatonin decrease prematurely. Once daily injection of 40 microg melatonin for 5 days at 19.30 h had no effect on metamorphic progress, or on plasma T(4) or melatonin levels, except for a transient rise in melatonin just after the injection. Immersion in 2.2x10(-4) M melatonin for 6 days accelerated metamorphosis and decreased plasma melatonin, but had no effect on plasma T(4). Administration of T(4) by injection of 0.2 microg, or immersion in a 6.3x10(-8) M solution accelerated metamorphosis more than melatonin immersion, raised plasma T(4) to climax levels, and induced a decrease in plasma melatonin. We conclude that rapid clearance of exogenous melatonin from the circulation in these experiments did not allow it to affect plasma T(4), and that there is clear evidence that the rise in T(4) induces the climax decrease in plasma melatonin. The finding that immersion in a high level of melatonin can lower plasma melatonin and accelerate metamorphosis, whereas a single daily injection does not, provides an explanation for some of the contradictory reports in the literature concerning melatonin's effect on tadpole metamorphic progress.     

Endocrinological effects of strong 60-Hz electric fields on rats

Adult male rats were exposed or sham-exposed to 60-Hz electric fields without spark discharges, ozone, or significant levels of other secondary variables. No effects were observed on body weights or plasma hormone levels after 30 days of exposure at an effective field strength of 68 kV/m. After 120 days of exposure (effective field strength = 64 kV/m), effects were inconsistent, with significant reductions in body weight and plasma levels of follicle-stimulating hormone and corticosterone occurring in one replicate experiment but not in the other. Plasma testosterone levels were significantly reduced after 120 days of exposure in one experiment, with a similar but not statistically significant reduction in a replicate experiment. Weanling rats, exposed or sham-exposed in electric fields with an effective field strength of 80 kV/m from 20 to 56 days of age, exhibited identical or closely similar growth trends in body and organ weights. Hormone levels in exposed and sham-exposed groups were also similar. However, there was an apparent phase shift between the two groups in the cyclic variations of concentrations of hormones at different stages of development, particularly with respect to follicle-stimulating hormone and corticosterone. We concluded that 60-Hz electric fields may bring about subtle changes in the endocrine system of rats, and that these changes may be related to alterations in episodic rhythms.     

Relationship between dietary tyrosine and plasma cholesterol in the rat

The present study was undertaken to measure the effects of dietary tyrosine added to fish protein and peanut meal on plasma cholesterol and plasma thyroid hormone levels in the rat. These dietary proteins were chosen because they contain similar amounts of tyrosine but release it at different rates during enzymatic hydrolysis. Casein was chosen as the reference protein. Supplementation was used to obtain tyrosine levels similar to that of casein. Male Sprague-Dawley rats were fed cholesterol-enriched diets containing 15% protein. After 3 weeks of experimental feeding, total postprandial plasma cholesterol was similar in the casein and peanut meal groups and significantly lower in the fish group. When added to the fish diet, tyrosine caused an increase in plasma cholesterol to a level similar to that of the casein group, whereas supplementation had no effect on plasma cholesterol of rats fed the peanut meal diet. The effects of dietary proteins or of tyrosine supplementation on cholesterol levels of the (density less than 1.006 g/mL) lipoprotein fraction were comparable, but not all significant, to those observed on total plasma cholesterol. In addition, casein and fish diets induced significantly higher levels of plasma triiodothyronine (T3) and lower levels of plasma thyroxine (T4) than did the peanut meal diet. However, the addition of tyrosine to the fish or the peanut meal diet did not modify the plasma thyroid hormone levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improving effect of dietary taurine supplementation on the oxidative stress and lipid levels in the plasma,liver and aorta of rabbits fed on a high-cholesterol diet

The effect of a high-cholesterol diet with or without taurine on lipids and oxidative stress in the plasma, liver and aorta of rabbits was investigated. The animals were maintained on a basal diet (control), a high-cholesterol diet (HC, 1% w/w), or a high- cholesterol diet supplemented with taurine (HCHT, 2.5% w/w) for two months. Taurine has an ameliorating effect on atherosclerosis together with a decreasing effect on the cholesterol and triglyceride levels in rabbits fed on an HC diet. The HCHT diet caused a significant decrease in the malondialdehyde (MDA) and diene conjugate (DC) levels in the plasma, liver and aorta of rabbits as compared to the HC group. This treatment did not alter the antioxidant system in the liver of rabbits in the HC group. Our findings indicate that taurine ameliorated oxidative stress and cholesterol accumulation in the aorta of rabbits fed on the HC diet and that this effect may be related to its antioxidative potential as well as its reducing effect on serum lipids.     

Testosterone treatment can increase circulating carotenoids but does not affect yellow carotenoid‐based plumage colour in blue tits Cyanistes caeruleus

A number of mechanisms are responsible for producing the variation in natural colours, and these need not act in isolation. A recent hypothesis states that carotenoid‐based coloration, in addition to carotenoid availability, is also enhanced by elevated levels of circulating testosterone (T). This has only been tested for carotenoid‐coloured bare parts in birds. We performed an experimental manipulation of T levels and examined the effects on the yellow carotenoid‐based breast plumage in captive yearling blue tits Cyanistes caeruleus, of which half received a diet supplemented with carotenoids. T treatment resulted in elevated plasma T compared to controls and carotenoid supplementation strongly increased plasma carotenoid levels. T treatment resulted in an additional increase in plasma carotenoid levels but only in the carotenoid‐supplemented males. Carotenoid supplementation resulted in more intense breast colour (carotenoid chroma), as expected. However, there was no effect of testosterone on plumage coloration at either dietary carotenoid level. Our results suggest that T can cause an increase in plasma carotenoid concentration, but that this does not necessarily lead to improved carotenoid‐based plumage coloration.     

Androgen levels and social interactions in breeding males of the peacock blenny

Nest-holder male Salaria pavo have lower circulating concentrations of 11-ketotestosterone (KT) at the beginning of the breeding season than at its peak. At that peak density of nesting males was higher as were the number of visits of sneaker males to nests and of agonistic interactions between nest-holders and sneaker males. There was no difference between the two dates either in the frequency of male-male interactions or in the frequency of courtship episodes. Thus, higher plasma levels in nest-holders might be explained by a more intense sneaking pressure at the peak of the breeding season. At that peak, nest-holders had higher plasma levels of KT and a higher testosterone (T) to KT metabolization index in the gonads than did floater males. Both nest-holders and floaters had higher levels of KT and T in the testicular gland than in the testis. The levels of both androgens in the testicular gland, but not in the testis, were correlated with circulating concentrations of KT. These results suggest that the testicular gland is the major source of circulating KT in blenniids. Nest-holders had higher metabolization indexes than floaters both in the testis and in the testicular gland, which suggests that nest holding status promotes the conversion of T into KT.     

Testosterone and avian life histories: the effect of experimentally elevated testosterone on corticosterone and body mass in dark-eyed juncos.

To assess whether alterations in the normal pattern of testosterone (T) secretion might be beneficial or detrimental, we studied a breeding population of dark-eyed juncos in which we elevated T experimentally and measured its effect on potential correlates of fitness. We treated both free-living and captive males with implants that were either empty (C-males, controls) or packed with T (T-males, experimentals). Timing of implant varied and was designed to mimic natural peak breeding levels except that peaks were either prolonged or premature. We bled the birds at recapture and analyzed their plasma, and that of their female mates, for T and corticosterone (B). We also measured body mass and fat score in free-living T- and C-males. In the field, T-implants elevated T and kept it elevated for at least a month. Experimental males also had higher B than controls. In captives, the effect of the implants on plasma T was detectable within 24 hr. B in captive T-males was again higher than in captive C-males. In females, neither T nor B differed between mates of T- and C-males. T-males implanted in early spring lost more mass between implant and recapture in late spring than did controls and also had lower fat scores when recaptured. When implants were inserted in summer, treatment did not influence mass. Elevated T in early spring apparently hastened the transition from the winter to the breeding mode of fat storage. We suggest that prolonged elevation of testosterone might be selected against because of the association between T and B. Premature elevation of T might be costly because of the resultant loss of mass and fat reserves, which could lead to mortality when spring snowstorms prevent access to food.     

Hazelnut oil administration reduces aortic cholesterol accumulation and lipid peroxides in the plasma, liver, and aorta of rabbits fed a high-cholesterol diet

Hazelnut oil (HO) is rich in monounsaturated fatty acids and antioxidants. We wanted to investigate the effect of HO on lipid levels and prooxidant-antioxidant status in rabbits fed a high-cholesterol (HC) diet. An HC diet caused significant increases in lipids and lipid peroxide levels in the plasma, liver, and aorta together with histopathological atherosclerotic changes in the aorta. Glutathione levels, glutathione peroxidase, and glutathione transferase activities decreased significantly, but superoxide dismutase activity and vitamin E and C levels remained unchanged in the livers of rabbits following HC diet. HO supplementation reduced plasma, liver, and aorta lipid peroxide levels and aorta cholesterol levels together with amelioration in atherosclerotic lesions in the aortas of rabbits fed an HC diet, without any decreasing effect on cholesterol levels in the plasma or liver. HO did not alter the antioxidant system in the liver in the HC group. Our findings indicate that HO reduced oxidative stress and cholesterol accumulation in the aortas of rabbits fed an HC diet.     

Expression of plasma membrane alkaline phosphatase in normal and regenerating choriocapillaris in the rabbit.

Ultrastructural histochemistry for plasma membrane nonspecific alkaline phosphatase was performed on the normal and regenerating choriocapillaris (CC) of rabbits. In normal animals the CC endothelium expressed little or no staining, whereas in regenerating CC the endothelium exhibited staining. The staining was most intense at the unfenestrated plasma membrane. As the capillaries matured and the fenestrated plasma membrane became more extensive, the staining was reduced and eventually eliminated. Pericytes did not stain in normal or regenerating CC.     

Hypertriglyceridemia and delayed clearance of fat load in transgenic rabbits expressing human apolipoprotein CIII

Apolipoprotein CIII (apoCIII) has been implicated in hypertriglyceridemia and plasma apoCIII independently predicts risk for coronary heart disease. While hypertriglyceridemia in patients has been demonstrated to correlate with elevated plasma apoCIII levels and reduced lipoprotein lipase (LPL) activity, apoCIII transgenic mice show elevated LPL activity. In this study, we generated transgenic (Tg) rabbits expressing human apoCIII gene exclusively in liver and investigated the effect of apoCIII overexpression on lipid metabolism of rabbits. In comparison with non-Tg littermates, Tg rabbits had 3- and 3.2-fold increases in fed and fasted plasma triglycerides, respectively. In contrast, no significant differences were observed in plasma total cholesterol and high density lipoprotein cholesterol levels between Tg and non-Tg rabbits. Analysis of lipoprotein fractions revealed that elevated plasma triglyceride levels in Tg rabbits were mainly attributed to an increase in very low density lipoprotein/chylomicron-sized particles. Furthermore, Tg rabbits showed markedly delayed clearance of plasma triglycerides accompanied with significantly reduced LPL activity in post-heparin plasma compared to that in non-Tg controls. In conclusion, these results indicate apoCIII transgenic rabbits develop hypertriglyceridemia with similar mechanism in hypertriglyceridemic patients via delayed clearance of plasma triglycerides, and could be used as a valuable tool for the study of human hyperlipidemia in relation with atherosclerotic disorders.     

Effects of Exogenous Androgen and Antiandrogen on Territorial and Nonterritorial Red-winged Blackbirds (Aves: Icterinae)

We investigated the role of testosterone (T) in territory establishment and maintenance in male red-winged blackbirds (Agelaius phoeniceus) by implanting exogenous T or pharmacological agents that block the action of T in nonterritorial floaters and territory owners. Floaters with artificially elevated plasma T levels were unable to obtain territories. Territory owners implanted with T did not expand their territories, although they engaged in more aggressive behavior than did control males. Flutamide, which binds to T receptors in target areas, had no effect on territoriality. However, most territory owners given a combination of flutamide and ATD, an aromatization blocker, lost portions of their territories even though they actively defended them. Our results 1) suggest that, although T influences aggressive behavior, elevated plasma levels alone are insufficient to overcome previously-established social relationships between territory owners or between owners and floaters; 2) indicate that impairing the action of T leads to reduced abilities of territory owners to maintain territories against vigorous challenges: and 3) support recent findings that T acts on reproductive behavior in birds through both androgenic and estrogenic metabolites.     

Effects of added dietary taurine on erythrocyte lipids and oxidative stress in rabbits fed a high cholesterol diet

Lipid peroxidation leads to damage of polyunsaturated fatty acids of membrane phospholipids. The contribution of oxidative stress to hypercholesterolemia-induced hemolytic anemia and the effects of addition of taurine on erythrocyte lipid composition, oxidative stress, and hematological data were studied in rabbits fed on a high cholesterol (HC) diet (1%, w/w) for 2 months. The effects of taurine on erythrocyte hemolysis and H2O2-induced lipid peroxidation were investigated in normal rabbit erythrocytes in vitro. The HC diet resulted in increases in plasma lipids and lipid peroxide levels as well as increases in cholesterol levels and the cholesterol:phospholipid ratio in the erythrocytes. This diet caused a hemolytic anemia, but lipid peroxide levels remained unchanged in the erythrocytes of the rabbits. Taurine (2.5%, w/w) added to the food has an ameliorating effect on plasma lipids and lipid peroxide levels in rabbits fed on a HC diet. This treatment also caused decreases in elevated erythrocyte cholesterol levels and cholesterol:phospholipid ratio due to the HC diet, but it did not prevent the hemolytic anemia and did not change erythrocyte lipid peroxide levels. In addition, in an in vitro study, taurine did not protect erythrocytes against H2O2-induced hemolysis or lipid peroxidation. These results show that the HC diet causes hemolytic anemia without any changes in erythrocyte lipid peroxidation, and taurine treatment was not effective against hemolytic anemia caused by the HC diet.