Relationship between cobalamin and folate deficiencies and anemia in dogs.

BACKGROUND: Megaloblastic, nonregenerative anemia is a well-known consequence of cobalamin or folate deficiencies in humans but is not recognized in hypocobalaminemic or hypofolatemic dogs. Establishment of relationships between hypocobalaminemia or hypofolatemia and hematologic disease would encourage vitamin B testing, and potentially supplementation, in anemic dogs. OBJECTIVES: To determine the prevalence of anemia in hypocobalaminemic or hypofolatemic dogs and to report the prevalence of hypocobalaminemia and hypofolatemia and nonregenerative anemia, macrocytosis, and anisocytosis in anemic dogs. ANIMALS: One hundred and fourteen client-owned dogs with known serum cobalamin and folate concentrations and CBCs and 42 client-owned anemic dogs. METHODS: Retrospective comparison of anemia prevalence in hypocobalaminemic or hypofolatemic and normocobalaminemic or normofolatemic dogs was performed. Prospective measurement of erythrocyte variables and cobalamin and folate concentrations in anemic dogs was carried out; relationships among hypocobalaminemia and regenerative status, mean corpuscular volume, and red cell distribution width were evaluated. RESULTS: Significant differences in prevalence of anemia between hypocobalaminemic (36%) and normocobalaminemic dogs (26%; P = .23) or between hypofolatemic (31%) and normofolatemic dogs (30%; P = .99) were not detected. Between hypocobalaminemic and normocobalaminemic dogs, no significant differences in prevalence of nonregenerative anemia (69% vs 63%; P = .65), macrocytosis (17% vs 0%; P = .53), or anisocytosis (28% vs 0%; P = .14) were detected. Anemic dogs had high prevalence of vitamin B deficiencies (nonregenerative: 64% hypocobalaminemic, 18% hypofolatemic; regenerative: 57% hypocobalaminemic, 21% hypofolatemic). CONCLUSIONS AND CLINICAL IMPORTANCE: The association between cobalamin and folate deficiencies and macrocytic, nonregenerative anemia established in humans is not routinely present in dogs.

Hyperhomocysteinemia in Greyhounds and its Association with Hypofolatemia and Other Clinicopathologic Variables.

BACKGROUND: Folate and cobalamin are essential cofactors for homocysteine (HCY) metabolism. Hyperhomocysteinemia, a multifactorial condition, may reflect B vitamin deficiency and is associated with increased risk of cardiovascular disease, thrombosis, and neurodegenerative and chronic gastrointestinal diseases in humans. Hyperhomocysteinemia has been reported in Greyhounds with suspected chronic enteropathy. OBJECTIVES: To evaluate the frequencies of and the association between hypofolatemia and hyperhomocysteinemia in Greyhounds. ANIMALS: Data and serum samples from 559 Greyhounds. METHODS: Nested case-control study. The frequency of hypofolatemia in Greyhounds was determined by a laboratory database search. The relationship between hyperhomocysteinemia (measured by gas chromatography-mass spectrometry) and hypocobalaminemia and hypofolatemia was evaluated, and its frequency compared between healthy Greyhounds and Greyhounds with thrombosis or chronic diarrhea. RESULTS: Hypofolatemia was identified in 172 of 423 (41%) Greyhounds and was more common in hypo- than in normocobalaminemic dogs (49% vs. 35%; P = .0064). Hyperhomocysteinemia was detected in 53 of 78 (68%) of Greyhounds, being more common in hypo- than in normofolatemic dogs (88% vs. 59%; P = .0175). All healthy Greyhounds, 21 of 30 (70%) of dogs with chronic diarrhea and 6 of 8 (75%) of those with thrombosis, were hyperhomocysteinemic. Serum HCY concentrations were inversely correlated with serum folate concentration (ρ = -0.28; P = .0386) and were positively associated with serum albumin concentration (ρ = 0.66; P = .0022). CONCLUSIONS AND CLINICAL RELEVANCE: Hyperhomocysteinemia occurs frequently in the Greyhound population. Its association with hypofolatemia suggests decreased intracellular availability of B vitamins, but the functional implications warrant further investigation. Hyperhomocysteinemia in Greyhounds potentially may serve as a spontaneous canine model to further investigate hyperhomocysteinemia in humans.

Immunity decreases, antioxidant system damages and tight junction changes in the intestine of grass carp (Ctenopharyngodon idella) during folic acid deficiency: Regulation of NF-κB, Nrf2 and MLCK mRNA levels.

This investigation used the same growth trial as the previous study, which showed that folic acid deficiency retarded growth in young grass carp (the percent weight gain of Groups 1-6 were 102.32 ± 3.41%, 137.25 ± 10.48%, 179.78 ± 3.95%, 164.33 ± 3.21%, 143.35 ± 8.12% and 115.28 ± 2.66%) [1]. In the present study, we investigated the effects of dietary folic acid on the immune response, antioxidant status and tight junctions in the intestine of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp were fed diets containing graded levels of folic acid at 0.10, 0.47, 1.03, 1.48, 1.88 and 3.12 mg kg(-1) diet for 8 weeks. The results indicated that acid phosphatase and lysozyme activities, and the complement component 3 content in the proximal intestine (PI), mid intestine (MI) and distal intestine (DI) were decreased with folic acid deficiency (0.1 mg kg(-1)) (P < 0.05). Folic acid deficiency (0.1 mg kg(-1)) up-regulated interleukin 1ß, interleukin 8, tumor necrosis factor α, nuclear factor κB p65 (NF-κB p65), IκB kinase α (IKK-α), IKK-ß and IKK-γ gene expression, meanwhile down-regulated interleukin 10, transforming growth factor ß, IκB and target of rapamycin gene expression in the PI, MI and DI (P < 0.05). These data suggested that folic acid deficiency decreased fish intestinal innate immune function may be partly contributed to the regulation of NF-κB p65 pathway. Moreover, the activities and corresponding gene expression of glutathione content, Cu/Zn superoxide dismutase, catalase, glutathione peroxidase, glutathione s-transferases and glutathione reductase in fish intestine were depressed by deficient folic acid diet (0.1 mg kg(-1)) (P < 0.05). Furthermore, folic acid deficiency (0.1 mg kg(-1)) down-regulated NF-E2-related factor 2 (Nrf2) gene expression, up-regulated Kelch-like-ECH-associated protein 1a (Keap1a) and Keap1b gene expression in fish intestine (P < 0.05). These data indicated that deficient folic acid diet damaged fish intestinal antioxidant capacity partly by regulating Nrf2/Keap1 pathway. Additionally, folic acid deficiency (0.1 mg kg(-1)) down-regulated claudin-b, claudin-c, claudin-3, occludin and zonula occludens 1 gene expression; whereas folic acid deficiency (0.1 mg kg(-1)) up-regulated claudin-12, claudin-15, myosin light chain kinase (MLCK) and p38 mitogen activated protein kinase (p38 MAPK) gene expression in the PI, MI and DI (P < 0.05), suggesting that folic acid deficiency may damage fish intestinal tight junctions associated with the mediation of MLCK and p38 MAPK gene expression. In conclusion, folic acid deficiency (0.1 mg kg(-1)) impaired fish intestinal immunity, antioxidant capacity and tight junctions.

Folic acid deficiency impairs the gill health status associated with the NF-κB, MLCK and Nrf2 signaling pathways in the gills of young grass carp (Ctenopharyngodon idella).

The aim of this study was to investigate the effect of dietary folic acid on fish growth, the immune and barrier functions of fish gills, and the potential mechanisms of these effects. Young grass carp (Ctenopharyngodon idella) were fed diets containing graded levels of folic acid at 0.10 (basal diet), 0.47, 1.03, 1.48, 1.88 and 3.12 mg kg(-1) diet for 8 weeks. The results showed that acid phosphatase and lysozyme activities and the complement component 3 content in fish gills decreased with folic acid deficiency (P < 0.05). Folic acid deficiency up-regulated liver-expressed antimicrobial peptide 1, interleukin 1ß, interleukin 8, tumor necrosis factor α, nuclear factor κB p65, IκB kinase α (IKK-α), IKK-ß and IKK-γ gene expression. Folic acid deficiency down-regulated interleukin 10, transforming growth factor ß, IκB and target of rapamycin gene expression in fish gills (P < 0.05). These results showed that limited folic acid decreased fish gill immune status. Furthermore, folic acid deficiency down-regulated claudin-b, claudin-c, claudin-3, occludin and zonula occludens 1 gene expression, whereas folic acid deficiency up-regulated claudin-12, claudin-15, myosin light chain kinase and p38 mitogen activated protein kinase gene expression in fish gills (P < 0.05). These results suggested that folic acid deficiency disrupted tight junction-mediated fish gill barrier function. Additionally, folic acid deficiency increased the content of reactive oxygen species, protein carbonyl and malondialdehyde (MDA); Mn superoxide dismutase activity and gene expression; and Kelch-like-ECH-associated protein 1a (Keap1a) and Keap1b gene expression (P < 0.05). Conversely, folic acid deficiency decreased Cu/Zn superoxide dismutase, catalase, glutathione peroxidase, glutathione s-transferases and glutathione reductase activities and gene expression as well as NF-E2-related factor 2 gene expression in fish gills (P < 0.05). All of these results indicated that folic acid deficiency impaired fish gill health status via regulating gene expression of cytokines, tight junction proteins, antioxidant enzymes, NF-κB p65, MLCK and Nrf2. Based on percent weight gain, LZ activity and MDA content in the gills, the dietary folic acid requirements for young grass carp were 1.60, 2.07 and 2.08 mg kg(-1), respectively.

Canine breed predispositions for marked hypocobalaminaemia or decreased folate concentration assessed by a laboratory survey.

OBJECTIVE: The aim of this study was to determine canine breed predispositions for decreased serum folate or markedly decreased cobalamin concentrations. METHODS: Retrospective analysis of samples from dogs that had serum folate and cobalamin concentrations measured, from 1990 to 2002 at the Comparative Gastroenterology Laboratory of Liverpool, were enrolled. A total of 13,069 samples were analysed. Those with trypsin-like immunoreactivity < 5·0 lg/L were excluded, and only breeds with at least 30 individuals tested were further analyzed. Breed predisposition was determined by calculating odds ratios and 95% confidence intervals for hypocobalaminaemia or decreased folate concentration. Significance was tested with a two-sided Fisher's exact test, and the level of statistical significance was set at P<0·05. RESULTS: A total of 9960 dogs fulfilled the inclusion criteria. Forty breeds contained at least 30 individuals. Predispositions for hypocobalaminaemia were identified in shar peis, Staffordshire bull terriers, German shepherd dogs and mixed breeds. Predispositions for decreased folate concentration were found in golden retrievers and boxers. CLINICAL SIGNIFICANCE: Predisposition for marked hypocobalaminaemia and decreased folate concentration differed between breeds. The shar peis had a markedly increased odds ratio for hypocobalaminaemia, as previously reported in North America, but other at-risk breeds were also identified.

Cobalamin, folate and inorganic phosphate abnormalities in ill cats.

Hypocobalaminaemia in cats has previously been identified, but the incidence reported has varied, and the frequency of folate deficiency is unknown. The aims of this study were to evaluate the incidence of low cobalamin and folate levels in a population of cats that were suffering predominantly from diseases of the alimentary tract (including the liver and pancreas) and to ascertain whether severity of disease (as assessed by bodyweight and body condition score (BCS)) related to degree of deficiency. The study population comprised 103 cats, of which 16.5% had low cobalamin levels and 38.8% had low folate levels. A serendipitous finding was inorganic phosphate levels below the reference range in 48% of the cases. Significant associations were found between subnormal cobalamin levels and median BCS (P=0.049); combined low folate and low cobalamin and bodyweight (P=0.002), BCS (P=0.024) and inorganic phosphate levels (P=0.003). The finding of low levels of folate and cobalamin in clinical cases suggests that supplementation may be indicated more frequently than is currently recognised.

Effects of dietary folate on ulcerative colitis-associated colorectal carcinogenesis in the interleukin 2- and beta(2)-microglobulin-deficient mice.

Folate supplementation may reduce the risk of colorectal dysplasia and cancer in subjects with chronic ulcerative colitis (UC). The interleukin (IL) 2- and beta(2)-microglobulin (beta(2)m)-deficient (IL-2(null) x beta(2)m(null)) mice spontaneously develop colon cancer in the setting of chronic UC. This study investigated the effects of dietary folate on the development of UC-associated colon cancer in the IL-2(null) x beta(2)m(null) mice. Weaning IL-2(null) x beta(2)m(null) mice were randomized to receive 0 (deficient; n = 40), 2 (basal requirement; control; n = 46), or 8 (supplemented; n = 36) mg folate/kg diet for 32 weeks. At necropsy, all macroscopic colonic tumors were identified and histologically classified as dysplasia or adenocarcinoma. The incidence of high-grade lesions (high-grade dysplasia/carcinoma in situ and invasive adenocarcinoma) in the folate-supplemented group was 46% lower than that in the control group (35.3% versus 65.1%, P = 0.009). The incidence of high-grade lesions in the folate-deficient group was also 49% lower than that in the control group (33.3% versus 65.1%, P = 0.007). The higher mortality rate in the folate-deficient group compared with the other two groups (25% versus 6.5% and 5.6%, P < 0.02) partially accounted for the low incidence of high-grade lesions in this group. These data indicate that dietary folate supplementation at 4x the basal dietary requirement significantly suppresses UC-associated colorectal carcinogenesis in the IL-2(null) x beta(2)m(null) mice. These data also suggest that folate deficiency may inhibit colorectal carcinogenesis in chronic UC. However, the high mortality observed in the folate-deficient group precludes a definitive conclusion concerning the effect of folate deficiency on UC-associated colorectal carcinogenesis in this model.

The dietary requirement of young rainbow trout (Oncorhynchus mykiss) for folic acid.

We sought to determine the dietary folic acid requirement of young rainbow trout using growth indices supported by measurements of tissue folate concentrations. The investigation was conducted with purified diets that had, by assay, basal folic acid levels of 0.08 and 0.16 mg/kg in the first and second, respectively, of two experiments. Each experiment was started with fry (initial mean weight, 1.4 and 2.8 g/fish in Experiments 1 and 2, respectively) and was conducted at a water temperature of 15 degrees C. Experiment 1 lasted 18 wk and Experiment 2 lasted 16 wk. Recovery tests (of 8 wk duration, performed on fish fed the unsupplemented diet) and pair-feeding showed that the unsupplemented diet led to a folate-specific deficiency condition in which the main hematological abnormality was the appearance of misshapen nuclei in a small proportion (2.3%) of erythrocytes. Dietary requirements were shown not to exceed 0.3 and 0.6 mg folic acid/kg (17 and 33 micrograms/MJ digestible energy) for optimizing survival and growth indices, respectively. We conclude that the dietary folate requirement of the trout is comparable to that of other vertebrates for the purpose of achieving maximal weight gain.

Folate deficiency in chicks fed diets containing practical ingredients.

Development of folate deficiency was evaluated in young chicks fed diets containing corn and soybean meal as major constituents. Folic acid deficiency, as indicated by retarded growth and feed efficiency, could be produced in 18-day-old chicks. Chicks fed the basal diet had increased growth when given supplements of either folic acid, choline Cl, or DL-methionine, but not vitamin B12. Relative liver size (grams per 100 g of body weight) was reduced by a methionine or methionine plus choline supplement in two experiments but by folic acid in only one of two experiments. Plasma hemoglobin was reduced by folic acid or a methionine and choline supplement after 42 days on the diets. Folic acid deficiency can be produced in young chicks with a diet based on practical ingredients. Purified diets or very high levels of antibiotic feeding are not necessary to produce folic acid deficiency as long as low levels of methionine and choline are present in the basal diet.

Hematologic values and plasma and tissue folate concentrations in dogs given phenytoin on a long-term basis.

During earlier investigations of the hepatic effects in dogs of long-term administration of phenytoin alone or in combination with primidone, erythrocytic macrocytosis, neutropenia, neutrophilic hypersegmentation, and thrombocytopenia were observed. Such abnormalities were observed most often in dogs given phenytoin and resembled those known to be attributable to folate deficiency in human beings with epilepsy treated with phenytoin. To pursue the theory that these hematologic aberrations were caused by drug-induced folate deficiency, 12 dogs were given a diet specifically formulated to contain a minimally adequate concentration of folate. After 2 weeks, phenytoin was administered daily (400 mg, PO, q 8 h) to 8 of the 12 dogs for 54 weeks. A CBC, bone marrow aspiration biopsy, and measurement of plasma and RBC folate concentrations were done every 3 weeks. Bone marrow aspirates were examined by transmission electron microscopy after 24 and 36 weeks, and at the end of the treatment period. Hepatic folate concentration was also determined in all dogs before and after treatment. Excretion of formiminoglutamic acid, as a marker of folate deficiency, was measured in all dogs at the end of the study. All dogs remained healthy throughout the treatment phase. Consistent abnormalities were not observed in the blood or bone marrow of treated dogs. Plasma and RBC folate concentrations decreased in control and treated dogs as a result of dietary restriction (P less than or equal to 0.02), and remained stable until the end of the study. The RBC folate content decreased further in treated dogs (P less than or equal to 0.02), although the hepatic folate content was similar in control and treated dogs. Treated dogs did not excrete formiminoglutamic acid more rapidly than did control dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Haematological and tissue abnormalities in chicks caused by acute and subclinical folate deficiency.

1. Haematological, histological and ultrastructural findings in young chicks fed on a purified diet severely deficient in folate are reported. 2. Growth of the birds was greatly depressed and they had a macrocytic anaemia. Other haematological changes included abnormal nuclear formations in erythrocytes, numerous mitoses and hypersegmented granulocytes. 3. Megaloblasts were observed in bone marrow and their fine structure is described for the first time in an avian species. 4. Morphological changes occurred also in the liver. The parenchyma had damaged sinusoidal endothelium, inflammatory cells and no glycogen. Mitochondria were damaged and many were associated with unusual crystalline structures. 5. Chickens fed on a semi-purified diet of low folate content showed no growth depression or clinical signs of deficiency but had abnormal haematological values and morphological changes that resembled those seen in birds fed on the purified diet. 6. These abnormalities responded to dietary supplements of pteroylmonoglutamic acid in a dose-related manner and may be useful in diagnosing subclinical folate deficiency.

Involvement of water-soluble vitamins in diseases of swine.

The various roles of the water-soluble vitamins (including choline and vitamin C) in diseases of swine are outlined. The most important role is in the prevention of deficiency disease; another important role is in relation to the immune response. Deficiency signs relating to each vitamin are described and the metabolism of each vitamin is outlined. Recent estimates of requirements are set out, together with suggestions on supplementation of practical diets for swine.

Vitamin B6 in the etiology of gizzard erosion in growing chickens.

Six experiments have been completed on day-old male cross-bred chicks for periods of up to 2 and 4 weeks to learn more about the role of pyridoxine in the etiology of gizzard erosion. At the end of each experiment, chicks were sacrificed and their gizzards removed and scored for the severity and incidence of erosion. The results of these experiments confirm the previous finding that the severity and incidence of gizzard erosion is increased by B6 deficiency. They further show that taurocholic acid, at 1% of the diet, had a protective effect against this erosion. Feeding B6-adequate rations to chicks that previously had been fed a B6-deficient diet led to partial healing of gizzard erosions. Results also indicate that the feeding of purified diets to growing chickens produces a higher incidence of erosion than that of practical-type diets. Texture of the diet did nt influence the incidence of the erosion, because grinding a practical diet to the same fineness as a purified diet did not increase gizzard erosion. Pair-feeding experiments showed that gizzard erosion in partially starved chicks was not a specific result of anorexia but of deficiencies in certain nutrients, one of which is vitamin B6.

The effects of folate deficiency and oestradiol administration on the plasma free amino acid concentrations of the immature hen.

1. Free amino acid concentrations were measured in the blood plasma of immature pullets receiving a folate-deficient diet and injected with folate and/or oestradiol, with appropriate controls. 2. Folate deficiency caused a decrease and oestradiol administration an increase in the plasma concentration of most of the amino acids studied. 3. Plasma glycine concentration increased in foliate deficiency and decreased with oestradiol treatment. 4. All the observed effects could not be readily explained in terms of the known metabolic role of folate in amino acid metabolism. 5. The results did not indicate that the role of folate in amino acid metabolism was significant in the inhibition of oestradiol-stimulated oviduct growth.

Leg bone abnormalities and histopathology of caged and floor reared broilers fed diets devoid of selected vitamins and minerals.

Summers et al., 1978, described an experiment in which performance and leg conditions of birds fed diets devoid of synthetic biotin, choline, folic acid, manganese, and miacin were observed and recoreded. This is a report on birds from the same experiment. Dyschondroplasia of the tibia was documented and the distal end of each tibia examined histologically. Metatarsal length and condyle depth of the distal tibia were also determined. Metatarsal length was influenced by vitamin deficiencies as well as the type of floor on which binds were raised. The depth of the intercondyle space was affected more by a manganese deficiency than by vitamin deficiencies and, in this case, was greater on plastic and litter as opposed to wire floors. There did not appear to be a correlation between the space depth and slipping of the tendons; however, a large number of birds should be examined to provide more data. Dyschondroplasia was more prevalent in choline deficient birds, particularly those birds raised on litter or plastic floors. Histology changes in relation to nutrient deficiencies were comparable to those reported previously.

Megaloblastic erythropoiesis and tissue depletion of folic acid in the cat.

Dietary requirement for folic acid was shown in the cat. Folic acid deficiency was produced by feeding young cats a deficient diet (0.125 mg of total folate/kg of dry weight by analysis) for 22 weeks. The folic acid-deficient cats grew normally, but had reduced plasma, red blood cell, and liver folate concentrations in comparison with those concentrations in cats fed a control diet (1.36 mg of total folate/kg).. Urinary excretion of formiminoglutamic acid was increased in all deficient diet cats 24 hours after L-histidine injection. Erythroblasts in bone marrow smears from folic acid-deficient cats were megaloblastic; they showed abnormal nuclear chromatin patterns and had nuclear-cytoplasmic asynchronism.