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Brown bears (Ursus arctos) hibernate for 5–7 months without eating, drinking, urinating, and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematological features of blood from hibernating and active free-ranging subadult brown bears with a focus on conservation of health and energy. We found that total plasma protein concentration increased during hibernation, even though the concentrations of most individual plasma proteins decreased, as did the white blood cell types. Strikingly, antimicrobial defense proteins increased in concentration. Central functions in hibernation involving the coagulation response and protease inhibition, as well as lipid transport and metabolism, were upheld by increased levels of very few key or broad specificity proteins. The changes in coagulation factor levels matched the changes in activity measurements. A dramatic 45-fold increase in sex hormone-binding globulin levels during hibernation draws, for the first time, attention to its significant but unknown role in maintaining hibernation physiology. We propose that energy for the costly protein synthesis is reduced by three mechanisms as follows: (i) dehydration, which increases protein concentration without de novo synthesis; (ii) reduced protein degradation rates due to a 6 °C reduction in body temperature and decreased protease activity; and (iii) a marked redistribution of energy resources only increasing de novo synthesis of a few key proteins. The comprehensive global data identified novel biochemical strategies for bear adaptations to the extreme condition of hibernation and have implications for our understanding of physiology in general.

Brown bears (Ursus arctos) hibernate for 5-7 months without eating, drinking, urinating and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematologic features of blood from hibernating and active free-ranging subadult brown bears with a focus on conservation of health and energy. We found that total plasma protein concentration increased during hibernation, even though the concentrations of most individual plasma proteins decreased, as did the white blood cell types. Strikingly, antimicrobial defense proteins increased in concentration. Central functions in hibernation involving the coagulation response and protease inhibition, as well as lipid transport and metabolism, were upheld by increased levels of very few key or broad-specificity proteins. The changes in coagulation factor levels matched the changes in activity measurements. A dramatic 45-fold increase in sex-hormone-binding-globulin SHBG levels during hibernation draws, for the first time, attention to its significant but unknown role in maintaining hibernation physiology. We propose that energy for the costly protein synthesis is reduced by three mechanisms, (i) dehydration, which increases protein concentration without de novo synthesis; (ii) reduced protein degradation rates due to a 6 °C reduction in body temperature, and decreased protease activity; and (iii) a marked redistribution of energy resources only increasing de novo synthesis of few key proteins. This comprehensive global data identified novel biochemical strategies for bear adaptations to the extreme condition of hibernation, and have implications for our understanding of physiology in general., Funding Agency:Lundbech Foundation R126-2012-12408Aalborg University

[EN] To alleviate the deleterious effect of heat stress during summer conditions on male rabbits’ reproduction, 40 V Line adult rabbit bucks (on av. 8 mo old) were divided into 4 experimental groups and exposed to temperatures ranging from 23 to 36°C. Bucks in the 1st, 2nd, 3rd, and 4th group were supplemented with 0, 50, 100 or 150 mg of Chinese royal jelly (RJ)/kg twice per week, respectively, over a 20-wk period. Semen quality and blood biochemical constituents were evaluated. RJ at any dose exhibited a significant increase (P<0.05) in rabbits’ sperm concentration, total sperm output, sperm motility, live sperm and normal sperm compared to the untreated controls. Plasma total protein, albumin, globulin, glucose and high density lipids (HDL) concentrations were significantly (P<0.05) boosted in the RJ groups compared to the controls. In contrast, RJ treatment resulted in a significant (P<0.05) reduction in plasma total lipids, triglycerides, cholesterol and low density lipids (LDL) concentrations. Treatment with RJ significantly boosted (P<0.05) testosterone concentration in the RJ groups to reach 110, 120 and 128%, respectively, of the control group. Improved kidney and liver functions were observed in the RJ bucks groups where plasma creatinine, urea concentrations, aspartate aminotransferase and alanine aminotransferase enzyme activities were significantly (P<0.05) decreased by RJ treatments. Treating bucks subjected to heat stress by different RJ doses increased (P<0.05) total antioxidant capacity to 106, 111 and 115% of basal, but significantly reduced (P<0.05) malondialdehyde and thiobarbituric acid reactive substances compared to the untreated. It was concluded that Chinese royal jelly supplementation for heat-stressed male rabbits can counteract summer infertility and improve their physiological status.

[EN] To alleviate the deleterious effect of heat stress during summer conditions on male rabbits’ reproduction, 40 V Line adult rabbit bucks (on av. 8 mo old) were divided into 4 experimental groups and exposed to temperatures ranging from 23 to 36°C. Bucks in the 1st, 2nd, 3rd, and 4th group were supplemented with 0, 50, 100 or 150 mg of Chinese royal jelly (RJ)/kg twice per week, respectively, over a 20-wk period. Semen quality and blood biochemical constituents were evaluated. RJ at any dose exhibited a significant increase (P<0.05) in rabbits’ sperm concentration, total sperm output, sperm motility, live sperm and normal sperm compared to the untreated controls. Plasma total protein, albumin, globulin, glucose and high density lipids (HDL) concentrations were significantly (P<0.05) boosted in the RJ groups compared to the controls. In contrast, RJ treatment resulted in a significant (P<0.05) reduction in plasma total lipids, triglycerides, cholesterol and low density lipids (LDL) concentrations. Treatment with RJ significantly boosted (P<0.05) testosterone concentration in the RJ groups to reach 110, 120 and 128%, respectively, of the control group. Improved kidney and liver functions were observed in the RJ bucks groups where plasma creatinine, urea concentrations, aspartate aminotransferase and alanine aminotransferase enzyme activities were significantly (P<0.05) decreased by RJ treatments. Treating bucks subjected to heat stress by different RJ doses increased (P<0.05) total antioxidant capacity to 106, 111 and 115% of basal, but significantly reduced (P<0.05) malondialdehyde and thiobarbituric acid reactive substances compared to the untreated. It was concluded that Chinese royal jelly supplementation for heat-stressed male rabbits can counteract summer infertility and improve their physiological status.

[EN] To alleviate the deleterious effect of heat stress during summer conditions on male rabbits’ reproduction, 40 V Line adult rabbit bucks (on av. 8 mo old) were divided into 4 experimental groups and exposed to temperatures ranging from 23 to 36°C. Bucks in the 1st, 2nd, 3rd, and 4th group were supplemented with 0, 50, 100 or 150 mg of Chinese royal jelly (RJ)/kg twice per week, respectively, over a 20-wk period. Semen quality and blood biochemical constituents were evaluated. RJ at any dose exhibited a significant increase (P<0.05) in rabbits’ sperm concentration, total sperm output, sperm motility, live sperm and normal sperm compared to the untreated controls. Plasma total protein, albumin, globulin, glucose and high density lipids (HDL) concentrations were significantly (P<0.05) boosted in the RJ groups compared to the controls. In contrast, RJ treatment resulted in a significant (P<0.05) reduction in plasma total lipids, triglycerides, cholesterol and low density lipids (LDL) concentrations. Treatment with RJ significantly boosted (P<0.05) testosterone concentration in the RJ groups to reach 110, 120 and 128%, respectively, of the control group. Improved kidney and liver functions were observed in the RJ bucks groups where plasma creatinine, urea concentrations, aspartate aminotransferase and alanine aminotransferase enzyme activities were significantly (P<0.05) decreased by RJ treatments. Treating bucks subjected to heat stress by different RJ doses increased (P<0.05) total antioxidant capacity to 106, 111 and 115% of basal, but significantly reduced (P<0.05) malondialdehyde and thiobarbituric acid reactive substances compared to the untreated. It was concluded that Chinese royal jelly supplementation for heat-stressed male rabbits can counteract summer infertility and improve their physiological status.

[EN] To alleviate the deleterious effect of heat stress during summer conditions on male rabbits’ reproduction, 40 V Line adult rabbit bucks (on av. 8 mo old) were divided into 4 experimental groups and exposed to temperatures ranging from 23 to 36°C. Bucks in the 1st, 2nd, 3rd, and 4th group were supplemented with 0, 50, 100 or 150 mg of Chinese royal jelly (RJ)/kg twice per week, respectively, over a 20-wk period. Semen quality and blood biochemical constituents were evaluated. RJ at any dose exhibited a significant increase (P<0.05) in rabbits’ sperm concentration, total sperm output, sperm motility, live sperm and normal sperm compared to the untreated controls. Plasma total protein, albumin, globulin, glucose and high density lipids (HDL) concentrations were significantly (P<0.05) boosted in the RJ groups compared to the controls. In contrast, RJ treatment resulted in a significant (P<0.05) reduction in plasma total lipids, triglycerides, cholesterol and low density lipids (LDL) concentrations. Treatment with RJ significantly boosted (P<0.05) testosterone concentration in the RJ groups to reach 110, 120 and 128%, respectively, of the control group. Improved kidney and liver functions were observed in the RJ bucks groups where plasma creatinine, urea concentrations, aspartate aminotransferase and alanine aminotransferase enzyme activities were significantly (P<0.05) decreased by RJ treatments. Treating bucks subjected to heat stress by different RJ doses increased (P<0.05) total antioxidant capacity to 106, 111 and 115% of basal, but significantly reduced (P<0.05) malondialdehyde and thiobarbituric acid reactive substances compared to the untreated. It was concluded that Chinese royal jelly supplementation for heat-stressed male rabbits can counteract summer infertility and improve their physiological status.

[EN] To alleviate the deleterious effect of heat stress during summer conditions on male rabbits’ reproduction, 40 V Line adult rabbit bucks (on av. 8 mo old) were divided into 4 experimental groups and exposed to temperatures ranging from 23 to 36°C. Bucks in the 1st, 2nd, 3rd, and 4th group were supplemented with 0, 50, 100 or 150 mg of Chinese royal jelly (RJ)/kg twice per week, respectively, over a 20-wk period. Semen quality and blood biochemical constituents were evaluated. RJ at any dose exhibited a significant increase (P<0.05) in rabbits’ sperm concentration, total sperm output, sperm motility, live sperm and normal sperm compared to the untreated controls. Plasma total protein, albumin, globulin, glucose and high density lipids (HDL) concentrations were significantly (P<0.05) boosted in the RJ groups compared to the controls. In contrast, RJ treatment resulted in a significant (P<0.05) reduction in plasma total lipids, triglycerides, cholesterol and low density lipids (LDL) concentrations. Treatment with RJ significantly boosted (P<0.05) testosterone concentration in the RJ groups to reach 110, 120 and 128%, respectively, of the control group. Improved kidney and liver functions were observed in the RJ bucks groups where plasma creatinine, urea concentrations, aspartate aminotransferase and alanine aminotransferase enzyme activities were significantly (P<0.05) decreased by RJ treatments. Treating bucks subjected to heat stress by different RJ doses increased (P<0.05) total antioxidant capacity to 106, 111 and 115% of basal, but significantly reduced (P<0.05) malondialdehyde and thiobarbituric acid reactive substances compared to the untreated. It was concluded that Chinese royal jelly supplementation for heat-stressed male rabbits can counteract summer infertility and improve their physiological status.