Serum concentrations of vitamin D metabolites, vitamins A and E, and carotenoids in six canid and four ursid species at four zoos

Crissey, Susan D.; Ange, Kimberly; Slifka, Kerri A.; Bowen, Phyllis E.; Stacewicz‐Sapuntzakis, Maria; Langman, Craig B.; Sadler, William; Ward, Ann

doi:10.1016/s1095-6433(00)00289-0

Cited by 17 publications

(12 citation statements)

References 22 publications

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“…Dogs have been found to have no to moderate concentrations of BC in circulation when consuming unsupplemented omnivorous diets that likely contain some carotenoids [173–176]. Dogs have colorless fat [147], so it appears that they do not accumulate BC in their adipose.…”

Section: Species Differences In β-Carotene Metabolismmentioning

confidence: 99%

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Meeting the Vitamin A Requirement: The Efficacy and Importance ofβ-Carotene in Animal Species

Green

Fascetti

2016

The Scientific World Journal

106

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Vitamin A is essential for life in all vertebrate animals. Vitamin A requirement can be met from dietary preformed vitamin A or provitamin A carotenoids, the most important of which is β-carotene. The metabolism of β-carotene, including its intestinal absorption, accumulation in tissues, and conversion to vitamin A, varies widely across animal species and determines the role that β-carotene plays in meeting vitamin A requirement. This review begins with a brief discussion of vitamin A, with an emphasis on species differences in metabolism. A more detailed discussion of β-carotene follows, with a focus on factors impacting bioavailability and its conversion to vitamin A. Finally, the literature on how animals utilize β-carotene is reviewed individually for several species and classes of animals. We conclude that β-carotene conversion to vitamin A is variable and dependent on a number of factors, which are important to consider in the formulation and assessment of diets. Omnivores and herbivores are more efficient at converting β-carotene to vitamin A than carnivores. Absorption and accumulation of β-carotene in tissues vary with species and are poorly understood. More comparative and mechanistic studies are required in this area to improve the understanding of β-carotene metabolism.

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Section: Species Differences In β-Carotene Metabolismmentioning

confidence: 99%

“…Crissey et al [176] analyzed serum from 6 captive wild canid species (African wild dog, arctic fox, gray wolf, maned wolf, Mexican wolf, and red wolf) and found no detectable carotenoids in any samples. Their analysis included BC, lutein, β -cryptoxanthin, lycopene, and α -carotene.…”

Section: Species Differences In β-Carotene Metabolismmentioning

confidence: 99%

Meeting the Vitamin A Requirement: The Efficacy and Importance ofβ-Carotene in Animal Species

Green

Fascetti

2016

The Scientific World Journal

106

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“…Little is known about 25OHD levels in bears, as only total 25OHD has been measured previously [15]–[17] with a non-significant decrease being reported during hibernation [15].…”

Section: Introductionmentioning

confidence: 99%

Vitamin D Status and Bone and Connective Tissue Turnover in Brown Bears (Ursus arctos) during Hibernation and the Active State

et al. 2011

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BackgroundExtended physical inactivity causes disuse osteoporosis in humans. In contrast, brown bears (Ursus arctos) are highly immobilised for half of the year during hibernation without signs of bone loss and therefore may serve as a model for prevention of osteoporosis.AimTo study 25-hydroxy-vitamin D (25OHD) levels and bone turnover markers in brown bears during the hibernating state in winter and during the active state in summer. We measured vitamin D subtypes (D2 and D3), calcitropic hormones (parathyroid hormone [PTH], 1,25-dihydroxy-vitamin D [1,25(OH)2D]) and bone turnover parameters (osteocalcin, ICTP, CTX-I), PTH, serum calcium and PIIINP.Material and MethodsWe drew blood from seven immobilised wild brown bears during hibernation in February and in the same bears while active in June.ResultsSerum 25-hydroxy-cholecalciferol (25OHD3) was significantly higher in the summer than in the winter (22.8±4.6 vs. 8.8±2.1 nmol/l, two tailed p - 2p = 0.02), whereas 25-hydroxy-ergocalciferol (25OHD2) was higher in winter (54.2±8.3 vs. 18.7±1.7 nmol/l, 2p<0.01). Total serum calcium and PTH levels did not differ between winter and summer. Activated 1,25(OH)2D demonstrated a statistically insignificant trend towards higher summer levels. Osteocalcin levels were higher in summer than winter, whereas other markers of bone turnover (ICTP and CTX-I) were unchanged. Serum PIIINP, which is a marker of connective tissue and to some degree muscle turnover, was significantly higher during summer than during winter.ConclusionsDramatic changes were documented in the vitamin D3/D2 ratio and in markers of bone and connective tissue turnover in brown bears between hibernation and the active state. Because hibernating brown bears do not develop disuse osteoporosis, despite extensive physical inactivity we suggest that they may serve as a model for the prevention of this disease.

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“…In contrast, the majority of plasma vitamin A in dog (70%) is transported as retinyl esters associated with lipoproteins, and only 30% as retinol bound to RBP4 [32]. Predominant reliance on lipoprotein bound retinyl esters for delivery of vitamin A to target organs is a peculiarity of members of the canid family that clearly distinguishes them from other mammals [35]. Consistent with the reports that only 30% of serum vitamin A is transported in dog as RBP4-retinol, we determined that serum RBP4 concentrations in dog were significantly lower than that in cynomolgus monkey (Fig 3).…”

Section: Discussionmentioning

confidence: 99%

Comparative pharmacokinetics and pharmacodynamics of the advanced Retinol-Binding Protein 4 antagonist in dog and cynomolgus monkey

et al. 2020

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Accumulation of lipofuscin bisretinoids in the retina contributes to pathogenesis of macular degeneration. Retinol-Binding Protein 4 (RBP4) antagonists reduce serum retinol concentrations thus partially reducing retinol delivery to the retina which decreases bisretinoid synthesis. BPN-14136 is a novel RBP4 antagonist with good in vitro potency and selectivity and optimal rodent pharmacokinetic (PK) and pharmacodynamic (PD) characteristics. To select a non-rodent species for regulatory toxicology studies, we conducted PK and PD evaluation of BPN-14136 in dogs and non-human primates (NHP). PK properties were determined following oral and intravenous administration of BPN-14136 in beagle dogs and cynomolgus monkeys. Dynamics of plasma RBP4 reduction in response to compound administration was used as a PD marker. BPN-14136 exhibited favorable PK profile in both species. Dosenormalized exposure was significantly higher in NHP than in dog. Baseline concentrations of RBP4 were considerably lower in dog than in NHP, reflecting the atypical reliance of canids on non-RBP4 mechanisms of retinoid trafficking. Oral administration of BPN-14136 to NHP induced a strong 99% serum RBP4 reduction. Dynamics of RBP4 lowering in both species correlated with compound exposure. Despite adequate PK and PD characteristics of BPN-14136 in dog, reliance of canids on non-RBP4 mechanisms of retinoid trafficking precludes evaluation of on-target toxicities for RBP4 antagonists in this species. Strong RBP4 lowering combined with good PK attributes and high BPN-14136 exposure achieved in NHP, along with the biology of retinoid trafficking that is similar to that of humans, support the choice of NHP as a non-rodent safety species.

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Serum concentrations of vitamin D metabolites, vitamins A and E, and carotenoids in six canid and four ursid species at four zoos

Cited by 17 publications

References 22 publications

Meeting the Vitamin A Requirement: The Efficacy and Importance ofβ-Carotene in Animal Species

Meeting the Vitamin A Requirement: The Efficacy and Importance ofβ-Carotene in Animal Species

Vitamin D Status and Bone and Connective Tissue Turnover in Brown Bears (Ursus arctos) during Hibernation and the Active State

Comparative pharmacokinetics and pharmacodynamics of the advanced Retinol-Binding Protein 4 antagonist in dog and cynomolgus monkey

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