Hypervitaminosis D in green iguanas

Two green iguanas, with a dietary supplement of vitamin D, calcium, and phosphorus, had gross and microscopic lesions of hypervitaminosis D characterized by massive deposition of calcium salts in the media of elastic arteries and terminal nephritis. Hypervitaminosis is a malady that should be kept in mind in dealing with captive wild animals, especially when exact nutritional requirements are not known.     

Pregnancy Monitoring in Dogs and Cats Using 3D and 4D Ultrasonography

Three-dimensional (3D)/four-dimensional (4D) volume ultrasound is an established method in human medicine that offers various options for analysing and presenting ultrasound volume data. However, the successful application of the different 3D/4D imaging modalities in pregnant dogs and cats has not yet been reported in the literature. The main reasons for this are: (1) the high costs of 3D/4D ultrasound systems, (2) operation difficulties due to high breathing frequency in non-sedated animals and (3) the missing specific knowledge in veterinary medicine concerning how to perform high-quality volume scans. Automatically acquired ultrasound volume data sets were generated with two different ultrasound systems: the portable Voluson i and the stationary Voluson Expert 730. Different 3D/4D imaging modalities were tested in regard of their practicability in pregnancy monitoring in dogs and cats. Nine different volume imaging modalities were applied using the saved files. For the presentation of the static 3D volume data sets, we used the multiplanar, niche, surface, transparency, glass body, inversion, volume calculation and tomographic ultrasound imaging modes. For the dynamic 4D data, the surface and glass body modes were applied. By changing the human standard settings to the requirements of small animal anatomy, it was found that 3D/4D ultrasound has great potential for the characterization of pregnancy in queens and bitches. The 3D/4D technology offered advanced information about pregnancy status and birth prediction and improved the diagnostic confidence. By using standardized examination protocols, 3D/4D ultrasound will allow a reduction in examination time by generating even more relevant information. These benefits, combined with possible future cost reduction of commercial ultrasound systems, might lead to frequent utilization in routine pregnancy diagnostic and birth management in small animal practice.     

Vitamin D intoxication and the pathogenesis of vitamin D nephropathy in the dog.

Dogs given excess vitamin D (500 or 1,000 micrograms/kg of body weight each day for 1 to 3 weeks were observed for clinical and pathologic changes of increased blood pressure and of characteristic nephropathy associated with vitamin D toxicosis or hypercalcemia. Serum calcium and serum urea nitrogen (UN) increased throughout the treatment period, but serum phosphorus remained within the normal range. Plasma renin activity increased markedly. Blood pressure showed only insignificnat changes (P = greater than 0.05). Gross and microscopic examination of the kidneys suggested vascular-oriented changes with an ischemic basis. Glomerular vascular poles showed hypertrophy and hyperplasia of juxtaglomerular cells. Ultrastructually, an increase in the number of secretory granules was noticed in these cells. A hypothesis regarding the mechanism of renal injury during vitamin D toxicosis is presented.     

Transfer of tritium-labeled vitamin D3 and 25-hydroxyvitamin D3 in ovine placenta

Placental transmission of IV-administered label from vitamin D3 and 25-hydroxycholecalciferol was studied in gestating ewes. Radioactivity concentrations were higher in the tissues of ewes dosed with vitamin D3 than in those dosed with 25-hydroxycholecalciferol. Concentrations were higher in maternal tissues than in fetal tissues. The highest radioactivity concentrations were found in kidneys, followed by concentrations in the adrenal glands.     

Seasonal vitamin D status of Greyhounds in Sydney

OBJECTIVES: To survey the vitamin D status of a population of Greyhounds in New South Wales, and to establish a reference range for plasma 25(OH)D. To investigate whether any seasonal fluctuation in vitamin D status is detectable in these animals. DESIGN: Vitamin D status was assessed in Greyhounds and crossbred dogs presented to the University of Sydney for teaching purposes over a 24 month period. PROCEDURES: Plasma 25(OH)D concentration was measured as an estimate of vitamin D status. Physical examination and plasma calcium concentration were used to verify the health of the animals, particularly with respect to metabolic bone disease. RESULTS: A plasma 25(OH)D concentration range of 10 to 76 nmol/L was found in healthy adult Greyhounds. There was no sex- or season-dependent variation in vitamin D status in Greyhounds. Concentrations in crossbred dogs did not differ significantly from those in Greyhounds. CONCLUSION: The reference range for plasma 25(OH)D concentration in Greyhound dogs is similar to that previously reported for humans. It would seem that healthy dogs in the Sydney region do not exhibit a seasonal fluctuation in their vitamin D status.     

The effect of intramuscularly administered vitamin D3 on serum vitamin D metabolites and electrolytes in vitamin D3 deficient dairy cows

The effect of intramuscular administration of vitamin D₃ (1×10⁶ IU D₃/100 kg bodyweight) to 3 different dairy breeds on the serum levels of vitamin D₃, 25-OH-D₂, 25-OH-D₃, Ca, inorganic P and Mg was studied.The vitamin metabolites and the electrolytes were analysed on 9 occasions during a 36-day period. Vitamin D₃ was analysed on 6 occasions during the same period. No significant breed differences were observed except for 25-OH-D₃ (P ≤ 0.05). The D₃ level rose in 1 day from < 2 ng/ml to 906 ng/ml and decreased to below 50 % of the peak level after 6 days. At the end of the experiment (day 36) vitamin D₃ was < 2 ng/ml. 25-OH-D₃ rose from < 2 ng/ml to 106 ng/ml in 6 days and stayed at this level during the whole experiment. 25-OH-D₂ decreased from 16 ng/ml to 5 ng/ml during the observation period.     

Methylamine induced hypophagia is mediated via dopamine D1 and D2 receptors in neonatal meat chicks

Recently, methylamine has been found as an endogenous amine, which is controling food intake in mammals. However, there is no evidence about the effect of methylamine on feeding behavior in poultry. So, the present study was designed to evaluate the effect of intracerebroventricular (ICV) injection of methylamine and involvement of central methylamine/dopaminergic systems on feeding behavior in neonatal meat type chicks. In experiment 1, chicks were ICV injected with different doses of methylamine (0.48, 0.96, 1.44, 1.92 and 2.40 μmol). In experiment 2, chicks received a dose of either the control solution, 2.40 μmol methylamine, 125 nmol L-DOPA (dopamine precursor) or a combination of methylamine plus L-DOPA. Experiments 3–7 were similar to experiment 2 except that 150 nmol 6-OHDA (dopamine synthase inhibitor), 5 nmol SCH23390 (D1 receptor antagonist), 5 nmol AMI-193 (D2 receptor antagonist), 6.4 nmol NGB2904 (D3 receptor antagonist) and 6 nmol L-741, 742 (D4 receptor antagonist) were used instead of 125 nmol L-DOPA, respectively. Cumulative food intake was determined until 2 h post-injection. According to the results, methylamine significantly decreased food intake in a dose dependent manner (p < 0.05). The inhibitory effect of methylamine on food intake was significantly attenuated by 6-OHDA, SCH23390 and AMI-193 (P < 0.05), but NGB2904 and L-741, 742 had no effect on food intake induced by methylamine. In addition, hypophagic effect of methylamine significantly amplified by L-DOPA (P < 0.05). These results suggest that methylamine decrease food intake and there is an interaction between methylamine and dopaminergic system via D1 and D2 receptors in chickens.     

Hypervitaminosis D in fur-bearing animals.

Investigations concerning the effect on fur-bearing animals of large doses of vitamin D3 were carried out. The material comprised 62 animals in all--10 silver foxes, 17 blue foxes and 35 mink (Table II). Daily doses of 5 IU vitamin D3/g body weight for two months did not produce clinical symptoms in the foxes. However, a short while after the dose was increased to 10 IU, the animals showed loss of appetite, had difficulty in moving, were apathetic and developed dark coloured faeces. Analysis of blood serum showed markedly raised calcium values (Table III). Calcium deposits were demonstrated in the kidneys and in some cases also in the musculature, gastric mucosa, bronchi and the larger blood vessels. No abnormal signs were shown by 30 mink which received 0.6--0.7 IU vitamin D3/g body weight for five months. PM findings were normal.     

家禽维生素D营养研究进展

维生素D是家禽需要的重要维生素之一。本文阐述了家禽维生素D的来源、新陈代谢和生物学功能、影响家禽维生素D需要量的因素以及维生素D的缺乏或过量对家禽生长发育和生产性能的影响 ,也为进一步研究维生素D提供了借鉴     

Effect of parenteral vitamin D3 on plasma 25-hydroxyvitamin D3 concentration in sheep

Vitamin D3 ranging in total amount from 10(5) iu (2.5 mg) to 9 X 10(5) iu (22.5 mg) was given intramuscularly either as a single injection or in three aliquots at three-weekly intervals to housed nonpregnant ewes on a vitamin D deficient diet. The effects on plasma concentrations of 25-hydroxyvitamin D3 (25-OHD3), the major metabolite of vitamin D, were monitored. The increase in plasma 25-OHD3 showed a large variation between animals and was related to, but not proportional to, the dose. None of the treatments produced 25-OHD3 concentrations greater than those in grazing sheep in summer. Repeated dosing provided for more efficient use of the injected vitamin D3.     

维生素D的免疫功能

维生素D是动物所必需的营养素,除对钙和骨代谢具有重要影响外,对免疫系统也有重要作用。1,25(OH)2维生素D3是维生素D的活性形式,1,25(OH)2维生素D3的生物学效应是由维生素D3受体(VDR)介导的。淋巴细胞、单核细胞、巨噬细胞等免疫细胞都有VDR的表达,这表明,维生素D对免疫系统功能有重要调节作用。     

Clostridium botulinum type D intoxication in a dairy herd in Ontario

Thirty-four Holstein cows died after exposure to Clostridium botulinum type D toxin, presumably from contaminated haylage. The presence of type D toxin in ruminal contents was confirmed by mouse inoculation. This is the first confirmation by direct toxin isolation of C. botulinum type D toxin in cattle in North America.     

2D versus 3D in the kinematic analysis of the horse at the trot

The handled trot of three Lusitano Purebred stallions was analyzed by using 2D and 3D kinematical analysis methods. Using the same capture and analysis system, 2D and 3D data of some linear (stride length, maximal height of the hoof trajectories) and angular (angular range of motion, inclination of bone segments) variables were obtained. A paired Student T-test was performed in order to detect statistically significant differences between data resulting from the two methodologies With respect to the angular variables, there were significant differences in scapula inclination, shoulder angle, cannon inclination and protraction-retraction angle in the forelimb variables, but none of them were statistically different in the hind limb. Differences between the two methods were found in most of the linear variables analyzed.     

Hypercalcemia and hypervitaminosis D in two lambs

Twin 17-day-old crossbred male lambs were examined to determine the cause of weakness and failure to thrive. Hypercalcemia attributable to hypervitaminosis D was diagnosed. The milk replacer or an accidental overdose of an injectable vitamin D product was suspected to be the source, although a definite cause was not confirmed. Lambs responded favorably to palliative treatment (administration of saline [0.9% NaCl] solution to induce calcium diuresis) and changing the diet to another milk replacer.     

Pathology of experimental vitamin D deficiency in chickens and effects of treatment with vitamin D metabolites

Structural changes in bone, parathyroid, and ultimobranchial body were examined in three groups of chicks fed a vitamin D-deficient diet; one group was treated with vitamin D3 and another with 1,25(OH)2D3. Diets were fed from day of hatching until 5 weeks old, when deficient chicks were near death due to hypocalcemic tetany, loss of fat and muscle, and marked bone deformities. In deficient chicks, parathyroid mass increased linearly to 7.5 times normal at 5 weeks. Parathyroid cells were irregular and vacuolated, with few granules. 1,25(OH)2D3 had normal parathyroids until the fifth week, when parathyroid mass increased greatly. There were few differences in length of growth cartilage, but marked changes in length of metaphyses. Deficient chicks had metaphyses nearly five times longer than vitamin D3-treated chicks. Metaphyses in chicks given 1,25(OH)2D3 were twice as long as those of vitamin D-treated chicks at 5 weeks. Both osteoblasts and osteoclasts were more numerous in deficient chicks. These studies suggest that vitamin D3 is more effective than 1,25(OH)2D3 in preventing parathyroid and bone lesions of vitamin D deficiency.     

维生素D受体在体外培养SD大鼠脂肪细胞中的表达

为了探索维生素D受体(VDR)在SD大鼠脂肪细胞分化过程中的表达规律,采用Ⅱ型胶原酶消化法进行SD大鼠脂肪细胞的分离培养,并将其诱导分化为成熟的脂肪细胞,分别在细胞生长至单层汇合后的第0、4、8、12、16天收集细胞样品。对VDR和脂滴进行荧光染色,同时采用Western blot对脂肪细胞分化过程中的VDR蛋白表达量进行分析,采用real-time PCR定量分析脂肪细胞分化过程中的VDR表达量。结果显示,随SD大鼠脂肪细胞的分化,细胞中脂滴逐渐增加,VDR mRNA和蛋白的表达量与脂质积累过程呈负相关性,表明VDR的表达在脂肪细胞分化过程中有一定的变化规律,其可能以负反馈的调节机制参与了脂肪细胞的分化过程。     

Pathology of experimental vitamin D deficiency in turkeys and the effects of various vitamin D supplements.

One-day-old poults fed a vitamin D3-deficient diet were examined for clinical, biochemical, and morphological changes at 14 days of age. Changes in these parameters were compared at 15.5 and 17 days of age after one of the following vitamin D-replacement therapies was provided: water-soluble vitamin-mineral packs that contained vitamin D3; vitamin D3 in the feed; or vitamin D, 1,25-dihydroxyvitamin D3 in the feed. The vitamin D3-deficient poults were lame and had significant decreases in weight gain and in longitudinal skeletal growth. None of the therapies alleviated all these changes, but clinical lameness subsided in poults provided 1,25-dihydroxyvitamin D3. Calcium concentrations were significantly improved by all therapies. Treatment with vitamin D3 in the feed and water significantly increased 25-hydroxyvitamin D3 concentrations in vitamin D-deficient poults. The growth plate zones, with the exception of the mineralized hypertrophied zone, were all increased in length and not modified by treatment. However, the mineralized hypertrophied zones in the 1,25-dihydroxy-vitamin D3 group and the group receiving vitamin D3 in the water were comparable to that in the controls on day 15.5.     

VD在骨骼外系统中的作用及其研究进展

以往普遍认为VD的主要功能是调节Ca离子来促进骨骼的生长和预防佝偻病,但最近几年的研究发现,VD不仅在骨骼疾病中起到重要作用,还与多种骨骼外疾病密切相关,包括一些心血管疾病、代谢紊乱有关的疾病、恶性肿瘤、过敏性疾病、自身免疫性疾病、生殖方面影响等。目前对VD生物学功能的研究比较全面和深入,但大部分是针对人体和小鼠的基础研究,对诸如牛、猪、犬、猫等不同动物VD的骨骼外系统生物学功能的研究较少。在查阅相关文献的基础上,通过对VD在血压、免疫调节、内分泌、子宫内膜和骨骼肌方面的生物学功能和研究进展进行总结,为不同动物VD在骨骼外系统生物学功能的研究提供一定参考。