Renal function in anesthetized dormant and active bears

Brown, D C; Mulhausen, Robert; Andrew, David J.; Seal, Ulysses S.

doi:10.1152/ajplegacy.1971.220.1.293

Cited by 48 publications

(39 citation statements)

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“…This is a markedly different response than the pronounced and consistent reduction in GFR observed in other mammals under reduced nutritional intake Ž or transitioning into natural or forced fasts Pullman et al, 1954;Brown et al, 1971;Boim and . Schor, 1992;Bosch, 1995 . It is also contradictory to estimates of renal filtration in weanling elephant seals based upon creatinine clearance Ž .…”

Section: Discussionmentioning

confidence: 75%

“…Most mammals, including the confamilial harbor seal, consistently demonstrate a postprandial hyperfiltration and a reduction in filtration associated with the cessa-Ž tion of food and water consumption Hiatt and Hiatt, 1942;Pullman et al, 1954;Brown et al, 1971;Nelson et al, 1973;Hladky and Rink, 1986;. Boim and Schor, 1992;Bosch, 1995 . In this study, the broad variability in GFR and mass-specific GFR, independent of food and water abstention or consumption, defines neither a postprandial hyperfiltration, nor a hypofiltration due to fasting or water abstention.…”

Section: Discussionmentioning

confidence: 99%

“…Typically, glomerular filtration rate GFR in-Ž creases by as much as 200% after feeding Hladky . and Rink, 1986 and declines by up to 32% in Ž fasted or nutrient-deprived mammals Pullman et al, 1954;Brown et al, 1971;Boim and Schor, . 1992;Bosch, 1995 .…”

Section: Northern Elephant Seals Mirounga Angu-mentioning

confidence: 99%

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Renal function in suckling and fasting pups of the northern elephant seal

Houser

Crocker

Webb

et al. 2001

Comparative Biochemistry and Physiology Part A: Molecular &

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Elephant seals fast for prolonged periods without access to water. This is made possible, in part, by reductions in urine production. However, the mechanisms involved in reducing urine production are not understood. In this study, Ž . Ž . glomerular filtration rate GFR was measured in five northern elephant seal pups Mirounga angustirostris via the inulin clearance technique. Measurements were made during day 9 and day 18᎐22 of nursing and the second and eighth week of the postweaning fast. Plasma aldosterone and cortisol concentrations, quantified by radioimmunoassay, were measured in eight other weanlings during the second and eighth week of the fast. Mean GFR was 79.3" 29.3 mlrmin during the early suckling period and 78.2" 17.1, 89.8" 52.7, and 80.4" 12.2 mlrmin during the late suckling, early fasting and late fasting periods, respectively. Differences between nursing and fasting were insignificant, possibly because reduced protein oxidation during suckling and rapid recruitment of protein for tissue synthesis obviated the need for postprandial hyperfiltration. Alternatively, maintenance of GFR during fasting may facilitate urea concentration by compensating for reductions in the fractional excretion of urea. It is further hypothesized that aldosterone is primarily responsible for mediating renal water reabsorption in this system. ᮊ

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Section: Discussionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 99%

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Renal function in suckling and fasting pups of the northern elephant seal

Houser

Crocker

Webb

et al. 2001

Comparative Biochemistry and Physiology Part A: Molecular &

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“…Hibernators such as the American black bear (Ursus americanus; Brown et al 1971), the hedgehog (Erinaceus europaeus; Clausen and Storesund 1971), the little brown bat (Myotis lucifugus; Gustafson and Belt 1981), prairie dogs (Cynomys leucurus and Cynomys ludovicianus; Harlow and Braun 1995), and the yellow-bellied marmot (Marmota flaviventris; Kastner et al 1978) experience periods as long as 7 mo without food and water, but they are essentially metabolically inactive during this time. In contrast, camels (Camelus dromedarius) may withstand prolonged periods (2-3 wk) of food and water deprivation in arid and hot environments without exhibiting deleterious effects (Ben Goumi et al 1993;Yagil 1993).…”

Section: Introductionmentioning

confidence: 99%

Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

Ortiz¹,

Crocker²,

Houser³

et al. 2006

Physiological and Biochemical Zoology

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The University of Chicago Press ABSTRACTThe renin-angiotensin-aldosterone system (RAAS) appears to contribute significantly to osmoregulation of fasting northern elephant seal (Mirounga angustirostris) pups; however, RAAS has not been characterized in fasting adult seals. Therefore, this study examined the contribution of RAAS to water turnover rates in fasting adult male northern elephant seals. Blood samples were obtained twice during their breeding fast at an interval of 6.5 wk, and water efflux rate was estimated by isotopic dilution during the same period. Serum electrolytes (Na ϩ , K ϩ , Cl Ϫ ) and osmolality were unaltered between the two sampling periods, indicating ionic and osmotic homeostasis during the fast. Despite the lack of an increase in vasopressin, serum angiotensin II and aldosterone were increased and were significantly and positively correlated. Changes in aldosterone concentration and water efflux rate were significantly and negatively correlated, suggesting that the greater the increase in aldosterone, the smaller the loss of water. Adult male seals maintain ionic and osmotic homeostasis similar to that of fasting weaned pups, and this homeostasis appears to be mediated, at least in part, by RAAS, which probably contributes to increased water retention as well. The hormonal mechanisms by which northern elephant seals maintain water and electrolyte balance during fasting conditions appear to be similar regardless of age.

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“…CRE is good indicator of renal function, with high values indicating impaired function (Stockham and Scott 2008). During hibernation, the glomerular filtration rate (GFR) in bears decreases by about 70% (Brown et al 1971). Besides, CRE is not metabolised and is cleared only by the kidney.…”

Section: Animalsmentioning

confidence: 99%

Blood chemistry reference intervals of captive Asiatic black bears (Ursus thibetanus)

Jeong¹,

Um²,

Lee³

et al. 2017

Vet. Med. - Czech

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Data on blood chemistry values can make fundamental contributions to our understanding of physiological changes. However, there is a lack of information regarding blood chemistry in Asiatic black bears (Ursus thibetanus). Thus, the objects of this study were to determine reference ranges for 29 blood chemistry variables, and to evaluate differences between age groups and between seasons. Blood samples (n = 138) were collected from 44 (20 males, 24 females; age range, 1-15 years) clinically healthy, captive Asiatic black bears (Ursus thibetanus) in the Republic of Korea. Young and adult bears showed significantly higher levels of creatinine and total cholesterol, and lower levels of blood urea nitrogen, blood urea nitrogen/creatinine ratio, lactate dehydrogenase and creatine kinase MB during hibernation compared to during non-hibernation. Adults also showed significantly higher levels of triglyceride, but lower levels of inorganic phosphorus, aspartate transaminase, alkaline phosphatase, high density lipoprotein cholesterol and creatine phosphokinase during hibernation than during non-hibernation. During hibernation, the urea nitrogen/creatinine ratio and levels of alkaline phosphatase, lactate dehydrogenase, and creatine phosphokinase in young bears were significantly higher than in adults, whereas creatinine levels were lower than in adults. During non-hibernation, the urea nitrogen/creatinine ratio and levels of calcium, alkaline phosphatase, lactate dehydrogenase, creatine phosphokinase and creatine kinase MB in young bears were significantly higher, whereas creatinine, total protein, albumin, gamma-glutamyl transferase and haemoglobin levels were lower than in adults. The results of this study provide reference values that will aid in understanding the physiology of Asiatic black bears and in assessing the health of these animals in captive environments.Keywords: Asiatic black bear; reference ranges; hibernation; blood chemistry; captivity; health assessment List of abbreviations ALB = albumin, ALP = alkaline phosphatase, ALT = alanine aminotransferase, AMY = amylase, AST = aspartate aminotransferase, BUN = blood urea nitrogen, CKMB = creatine kinase MB, CPK = creatine phosphokinase, CRE = creatinine, CRP = C-reactive protein, DBIL = direct bilirubin, GGT = gamma-glutamyl transferase, GLU = glucose, Hb = haemoglobin, HDLC = high density lipoprotein cholesterol, IP = inorganic phosphorus, LDH = lactate dehydrogenase, TBIL = total bilirubin, TCHO = total cholesterol, TG = triglyceride, TP = total protein, U/C = blood urea nitrogen to creatinine ratio, UA = uric acidBlood chemistry values can play a fundamental role in facilitating an understanding of physiological changes and in assessing potential health problems at both individual and population levels (Geffre et al. 2009;Friedrichs et al. 2012). Previously, blood chemistry data have been report-

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Renal function in anesthetized dormant and active bears

Cited by 48 publications

References 0 publications

Renal function in suckling and fasting pups of the northern elephant seal

Renal function in suckling and fasting pups of the northern elephant seal

Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

Blood chemistry reference intervals of captive Asiatic black bears (Ursus thibetanus)

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