Effect of dietary glycine and benzoate level on benzoate metabolism in mink (Mustela vision), blue fox (Alopex lagopus), and raccoon dog (Nyctereutes procyonoides).

Growth hormone (G H ) promotes growth and endochondral ossification, but it is also important in the response to fasting due to its effects of increasing gluconeogenesis and lipolysis. In this study eleven raccoon dogs and blue foxes were followed for six months and their body mass and GH levels were measured. In November half of the animals of both species were put to a three-week fast. There were no significant differences in the GH levels between the animals of different ages and the subadults and adults both had quite low GH levels in the summer. Fasting had no effect on the GH levels of the raccoon dogs, but the fasting blue foxes had lower GH concentrations than the controls in Nov 16th. The control blue foxes experienced a significant increase in the GH levels in early November and the fasting blue foxes in late November. The GH concentrations of all the raccoon dogs rose in early December. As fasting did not cause an elevation in the GH levels but the concentrations increased with decreasing temperature and shortening daylength, the autumnal GH secretion of these species could be regulated by endogenous seasonal rhythms entrained by exogenous Zeitgebers such as temperature or photoperiod. The autumnal increase of GH levels contributes to the response to fasting as an adaptation to survive the winter months with inadequate nutrition. The raccoon dog which spends the coldest part of the winter in winter sleep seems to be better adapted to a total fast than the actively wintering blue fox.

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Pineal Gland Morphology in Relation to Age and Season in Three Canidae Species

Journal of Morphological Sciences ◽

10.1055/s-0039-1698373 ◽

2019 ◽

Vol 36 (04) ◽

pp. 247-254

Author(s):

Svetlana Kalinina ◽

Viktor Ilyukha ◽

Lyudmila Uzenbaeva

Keyword(s):

Pineal Gland ◽

Morphological Changes ◽

Nyctereutes Procyonoides ◽

Raccoon Dog ◽

Silver Fox ◽

Reticular Fibers ◽

Different Ages ◽

Blue Fox ◽

Species Specific ◽

Insight Into

Abstract Introduction The aim of the present study was to determine the morphological features of the pineal gland in three closely related Canidae species (raccoon dog, Nyctereutes procyonoides Gray, 1834; silver fox, Vulpes vulpes L., 1758; and blue fox, Vulpes lagopus L., 1758) of different ages during the breeding (spring) and nonbreeding (winter) periods. Materials and Methods Histological analysis of the pineal glands of canids was performed. Results The morphological changes in the pineal gland detected in the current study are either age-associated, including increase in the reticular fibers and vascularization in the studied species, as well as increase in the amount of the protruding septae in the blue fox, or seasonally related, including an increase in the number and size of blood vessels. The present work reported two types of pigments: lipofuscin (primarily in the silver fox) and melanin (primarily in the raccoon dog and in the blue fox). The pineal gland in the blue fox is characterized by the ability to form corpora arenacea. Conclusions The present study provides the first insight into the morphological changes of the pineal gland in three closely related Canidae species of different ages during the breeding (spring) and nonbreeding (winter) periods, and showed some species-specific features of gland morphology. The aspects concerning the biogenesis of the calcium concretions and the factors influencing the accumulation of pigments need further investigation.

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Species- and age-dependent distribution of retinol and α-tocopherol in the Canidae family during the cold season

Biological Communications ◽

10.21638/spbu03.2021.304 ◽

2021 ◽

Vol 66 (3) ◽

Author(s):

Irina Baishnikova ◽

Tatiana Ilyina ◽

Viktor Ilyukha ◽

Konstantin Tirronen

Keyword(s):

Vulpes Vulpes ◽

Interspecific Hybrids ◽

Cold Season ◽

The Body ◽

Kidney Cortex ◽

Nyctereutes Procyonoides ◽

Raccoon Dog ◽

Silver Fox ◽

Age Related ◽

Blue Fox

Vitamins A and E are known as nutrients involved in metabolic processes and facilitating the adaptation of animals. The metabolism of these vitamins is closely related to lipid metabolism, which has seasonal variations in animals inhabiting northern latitudes. The aim of this study was to investigate the concentrations of retinol (vitamin A) and α-tocopherol (vitamin E) in the cold season (October to February) in tissues of Canidae species that have different ecological characteristics: the blue fox (Vulpes syn. Alopex lagopus), silver fox (Vulpes vulpes), their interspecific hybrids (Vulpes×Vulpes), raccoon dog (Nyctereutes procyonoides), and grey wolf (Canis lupus). In addition, age-related differences in the levels of these vitamins were determined. Results showed the distribution of retinol and α-tocopherol in the body of the canids was similar, with larger amounts being found in the liver and kidney cortex, which play a regulatory role in the metabolism of these nutrients. The higher retinol level in the liver of wolves and interspecific hybrids of blue fox and silver fox, as compared to the retinol level in the liver of other species, might be species-specific and could also be attributed to dietary differences. The blue fox and raccoon dog both have a higher capacity for α-tocopherol accumulation in the cold season, apparently due to their ability to store substantial fat reserves. Retinol and α-tocopherol levels were generally higher in the tissues of mature animals.

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