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Titon Junior B, Barsotti AMG, Titon SCM, Vaz RI, de Figueiredo AC, Vasconcelos-Teixeira R, Navas CA, Gomes FR. Baseline and stress-induced steroid plasma levels and immune function vary annually and are associated with vocal activity in male toads (Rhinella icterica). Gen Comp Endocrinol 2024; 354:114517. [PMID: 38615755 DOI: 10.1016/j.ygcen.2024.114517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 03/19/2024] [Accepted: 04/06/2024] [Indexed: 04/16/2024]
Abstract
Theoretical models predict that elevated androgen and glucocorticoid levels in males during the reproductive season promote immunosuppression. However, some studies report decreased stress response during this season. This study investigated annual variation in plasma corticosterone and testosterone levels, plasma bacterial killing ability (BKA), and neutrophil to lymphocyte ratio (NLR) in free-living male toads (Rhinella icterica). Toads were sampled in the field (baseline) and 1 h-post restraint over five months, and we considered the occurrence of vocal activity. Baseline corticosterone, testosterone, and BKA showed higher values during the reproductive period, specifically in calling male toads. The NLR was similar throughout the year, but higher values were observed in calling toads. Moreover, baseline NLR and BKA were positively correlated with both testosterone and corticosterone, suggesting higher steroid levels during reproduction are associated with enhanced cellular and humoral immunity. Despite fluctuation of baseline values, post-restraint corticosterone levels remained uniform over the year, indicating that toads reached similar maximum values throughout the year. Testosterone levels decreased following restraint before one specific reproductive period but increased in response to restraint during and after this period. Meanwhile, BKA decreased due to restraint only after the reproductive period, indicating immune protection and resilience to immunosuppression by stressors associated with steroid hormones during reproduction. Our results show that baseline and stress-induced hormonal and immune regulation varies throughout the year and are associated with vocal activity in R. icterica males, indicating a possible compromise between steroids and immune function in anuran males.
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Affiliation(s)
- Braz Titon Junior
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brasil.
| | | | | | - Renata Ibelli Vaz
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | - Aymam Cobo de Figueiredo
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | | | - Carlos A Navas
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | - Fernando Ribeiro Gomes
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brasil
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Anparasan L, Hobson KA. Tracing sources of carbon and hydrogen to stored lipids in migratory passerines using stable isotope (δ 13C, δ 2H) measurements. Oecologia 2021; 195:37-49. [PMID: 33389017 DOI: 10.1007/s00442-020-04827-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 12/09/2020] [Indexed: 11/29/2022]
Abstract
Using measurements of naturally occurring stable isotopes in feathers to determine avian origin and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, a major migratory fuel, has not been attempted. This study explores isotopic links between diet and stored lipids in captive white-throated sparrows (Zonotrichia albicollis) by providing isotopically distinct mixtures of carbohydrates/oils and drinking water and assessing the δ13C and δ2H values of stored lipid, breath CO2 (δ13C) and breath water vapour (δ2H). Stored lipid δ13C and δ2H values correlated with the isotopic values found in dietary carbohydrates/oils and drinking water treatments, respectively, indicating a clear traceable transfer of environmental dietary isotopic signals into body lipids. Dietary oils and carbohydrates contributed 80-82% of carbon and 44-46% of hydrogen, respectively, to stored lipids. Drinking water contributed 18-28% of hydrogen to stored lipids. Isotopic relationships were quantifiable using linear calibration algorithms which provide the basis for the construction of tissue isoscapes for migratory passerines. Breath CO2 δ13C values and breath water vapour δ2H values for fed and fasted birds reflected dietary sources. Breath CO2 δ13C values were higher for fasted birds than for fed birds by an average of 4.5‰ while breath water vapour δ2H values were lower for fasted birds by an average of 48.9‰. These results indicate that lipids and metabolites from their subsequent breakdown for fuel isotopically reflect dietary sources but complicate interpretation of such data, especially for wild migrating birds. Applications and limitations of these findings to the creation of "liposcapes" are examined.
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Affiliation(s)
- Libesha Anparasan
- Department of Biology, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada.
| | - Keith A Hobson
- Department of Biology, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada.,Environment and Climate Change Canada, Saskatoon, SK, S7N 3H5, Canada
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Rogers EJ, Sommers AS, McGuire LP. Seasonal Dynamics of Lipid Metabolism and Energy Storage in the Brazilian Free-Tailed Bat. Physiol Biochem Zool 2019; 92:386-395. [DOI: 10.1086/704107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Dorr BS, Hanson-Dorr KC, Assadi-Porter FM, Selen ES, Healy KA, Horak KE. Effects of Repeated Sublethal External Exposure to Deep Water Horizon Oil on the Avian Metabolome. Sci Rep 2019; 9:371. [PMID: 30674908 PMCID: PMC6344488 DOI: 10.1038/s41598-018-36688-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 11/23/2018] [Indexed: 12/19/2022] Open
Abstract
We assessed adverse effects of external sublethal exposure of Deepwater Horizon, Mississippi Canyon 252 oil on plasma and liver metabolome profiles of the double-crested cormorant (Phalacrocorax auritus), a large (1.5 to 3.0 kg) diving waterbird common in the Gulf of Mexico. Metabolomics analysis of avian plasma showed significant negative effects on avian metabolic profiles, in some cases after only two external exposures (26 g cumulative) to oil. We observed significant (p < 0.05) changes in intermediate metabolites of energy metabolism and fatty acid and amino acid metabolic pathways in cormorants after repeated exposure to oil. Exposure to oil increased several metabolites (glycine, betaine, serine and methionine) that are essential to the one-carbon metabolism pathway. Lipid metabolism was affected, causing an increase in production of ketone bodies, suggesting lipids were used as an alternative energy source for energy production in oil exposed birds. In addition, metabolites associated with hepatic bile acid metabolism were affected by oil exposure which was correlated with changes observed in bile acids in exposed birds. These changes at the most basic level of phenotypic expression caused by sublethal exposure to oil can have effects that would be detrimental to reproduction, migration, and survival in avian species.
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Affiliation(s)
- Brian S Dorr
- US Department of Agriculture, Wildlife Services, National Wildlife Research Center, MS State, MS, 39762, USA.
| | - Katie C Hanson-Dorr
- US Department of Agriculture, Wildlife Services, National Wildlife Research Center, MS State, MS, 39762, USA
| | - Fariba M Assadi-Porter
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Ebru Selin Selen
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Katherine A Healy
- US Fish and Wildlife Service, Deepwater Horizon Natural Resource Damage Assessment and Restoration Office, Fairhope, AL, 36532, USA
| | - Katherine E Horak
- US Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, CO, 80521, USA
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McClelland GB, Lyons SA, Robertson CE. Fuel Use in Mammals: Conserved Patterns and Evolved Strategies for Aerobic Locomotion and Thermogenesis. Integr Comp Biol 2018; 57:231-239. [PMID: 28859408 DOI: 10.1093/icb/icx075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
SYNOPSIS Effective aerobic locomotion depends on adequate delivery of oxygen and an appropriate allocation of metabolic substrates. The use of metabolic substrates during exercise follows a predictive pattern of lipid and carbohydrate oxidation that is similar in lowland native cursorial mammals. We have found that in two highland lineages of mice (Phyllotis and Peromyscus) the fuel use pattern is shifted to a greater reliance on carbohydrates compared to their lowland conspecifics and congenerics. However, there is variation between lineages in the importance of phenotypic plasticity in the expression of this metabolic phenotype. Moreover, this metabolic phenotype is independent of running aerobic capacity and can also be independent of thermogenic capacity. For example, wild-caught mice from a highland population of deer mice (Peromyscus maniculatus) housed in warm normoxic laboratory conditions maintain higher maximum cold-induced oxygen consumption in acute hypoxia than lowland congenerics, but shivering and non-shivering thermogenesis is supported by high rates of lipid oxidation. This is reflected in the consistently higher activities of oxidative and fatty acid oxidation enzymes in the gastrocnemius of highland deer mice compared to lowlanders, which are resistant to hypoxia acclimation. While a fixed trait in muscle aerobic capacity may reflect the pervasive and unremitting low PO2 at high altitudes, muscle capacities for substrate oxidation may be more flexible to match appropriate substrate use with changing energetic demands. How shivering thermogenesis and locomotion potentially interact in the matching of muscle metabolic capacities to appropriate substrate use is unclear. Perhaps it is possible that shivering serves as "training" to ensure muscles have the capacity to support locomotion or visa-versa.
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Affiliation(s)
- Grant B McClelland
- Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1
| | - Sulayman A Lyons
- Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1
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Energy metabolism during endurance flight and the post-flight recovery phase. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:431-438. [PMID: 28224277 DOI: 10.1007/s00359-017-1150-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/31/2016] [Accepted: 01/26/2017] [Indexed: 01/10/2023]
Abstract
Migrating birds are known to fly non-stop for thousands of kilometres without food or water intake and at a high metabolic rate thereby relying on energy stores which were built up preceding a flight bout. Hence, from a physiological point of view the metabolism of a migrant has to switch between an active fasting phase during flight and a fuelling phase during stopover. To meet the energetic and water requirements of endurance flight, migratory birds have to store an optimal fuel composition and they have to be able to quickly mobilize and deliver sufficient energy to the working flight muscles. After flight, birds have to recover from a strenuous exercise and sleeplessness, but, at the same time, they have to be alert to escape from predators and to prepare the next flight bout. In this overview, metabolic adaptations of free-ranging migrants to both phases will be presented and compared with results from windtunnel studies. The questions whether migratory strategy (long distance versus short distance) and diet composition influence the metabolic pathways will be discussed.
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Titon SCM, de Assis VR, Titon B, Barsotti AMG, Flanagan SP, Gomes FR. Calling rate, corticosterone plasma levels and immunocompetence of Hypsiboas albopunctatus. Comp Biochem Physiol A Mol Integr Physiol 2016; 201:53-60. [DOI: 10.1016/j.cbpa.2016.06.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 10/21/2022]
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8
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Price E, McGuire L, Fenton M, Guglielmo C. Flight muscle carnitine palmitoyl transferase activity varies with substrate chain length and unsaturation in the hoary bat (Lasiurus cinereus). CAN J ZOOL 2014. [DOI: 10.1139/cjz-2013-0141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fat is an important fuel for bats to support high metabolic rates in extended periods of flight. The fatty acid composition of adipose stores could affect whole animal exercise performance, as fatty acids vary in rates of mobilization and oxidation. A key step in the fatty acid oxidation pathway is transporting fatty acids from the cytosol into mitochondria, mediated by the enzyme carnitine palmitoyl transferase (CPT). Therefore, understanding the substrate preference patterns of CPT in bats is important for interpreting the consequences of adipose fatty acid profiles. We measured CPT activity with eight different fatty acyl CoA substrates (16:0, 16:1ω7, 18:0, 18:1ω9, 18:2ω6, 18:3ω3, 20:4ω6, and 22:6ω3) in the pectoralis muscle of migrating and nonmigrating hoary bats (Lasiurus cinereus (Beauvois, 1796)). The pattern of substrate preference was similar to the patterns previously reported for birds and rats and was not affected by migration. Generally, activity increased with the number of double bonds and was higher with 16 carbon fatty acids compared with 18 carbon fatty acids. Given the observed substrate variation in CPT activity, there is no evidence to suggest that recently reported seasonal changes in the adipose fatty acid composition of migrating hoary bats would lead to increased lipid oxidation rate, and may instead be a consequence of seasonal shifts in diet.
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Affiliation(s)
- E.R. Price
- Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada
| | - L.P. McGuire
- Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada
| | - M.B. Fenton
- Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada
| | - C.G. Guglielmo
- Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada
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Cornelius JM, Boswell T, Jenni-Eiermann S, Breuner CW, Ramenofsky M. Contributions of endocrinology to the migration life history of birds. Gen Comp Endocrinol 2013; 190:47-60. [PMID: 23602795 DOI: 10.1016/j.ygcen.2013.03.027] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 03/24/2013] [Accepted: 03/25/2013] [Indexed: 11/29/2022]
Abstract
Migration is a key life cycle stage in nearly 2000 species of birds and is a greatly appreciated phenomenon in both cultural and academic arenas. Despite a long research tradition concerning many aspects of migration, investigations of hormonal contributions to migratory physiology and behavior are more limited and represent a comparatively young research field. We review advances in our understanding of the hormonal mechanisms of migration with particular emphasis on the sub-stages of the migration life history: development, departure, flight and arrival. These sub-stages vary widely in their behavioral, ecological and physiological contexts and, as such, should be given appropriate individual consideration.
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Affiliation(s)
- J M Cornelius
- Department of Neurobiology, Physiology and Behavior, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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10
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de Assis VR, Navas CA, Mendonça MT, Gomes FR. Vocal and territorial behavior in the Smith frog (Hypsiboas faber): Relationships with plasma levels of corticosterone and testosterone. Comp Biochem Physiol A Mol Integr Physiol 2012; 163:265-71. [DOI: 10.1016/j.cbpa.2012.08.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 08/05/2012] [Accepted: 08/07/2012] [Indexed: 11/24/2022]
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12
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Price ER, Staples JF, Milligan CL, Guglielmo CG. Carnitine palmitoyl transferase activity and whole muscle oxidation rates vary with fatty acid substrate in avian flight muscles. J Comp Physiol B 2010; 181:565-73. [PMID: 21153644 DOI: 10.1007/s00360-010-0542-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 11/05/2010] [Accepted: 11/26/2010] [Indexed: 11/27/2022]
Abstract
Birds primarily fuel migratory flights with fat, and the composition of that fat has the potential to affect overall lipid oxidation rates. We measured the whole muscle lipid oxidation rates in extensor digitorum communis muscles from white-throated sparrows (Zonotrichia albicollis Gmelin) incubated for 20 min at 20°C with radiolabeled stearate (18:0), oleate (18:1ω9), or linoleate (18:2ω6). Lipid oxidation rates were ~40% higher with linoleate than oleate (oleate: 36 ± 8.54 μmol CO(2) g(-1) h(-1)), and ~75% lower with stearate compared with oleate, indicating that maximal lipid oxidation rates can indeed be affected by the type of fatty acid supplied to the muscle. Additionally, we investigated the activity of the mitochondrial fatty acid transport-associated enzyme carnitine palmitoyl transferase (CPT) in pectoralis muscles of 5 bird species (Zonotrichia albicollis, Philomachus pugnax, Sturnus vulgaris, Taeniopygia guttata, Passer domesticus). Activity was measured in homogenized samples using various fatty acyl-CoA substrates (16:0, 16:1, 18:0, 18:1ω9, 18:2ω6, 18:3ω3, 18:3ω6, 20:0, 20:4ω6, 22:6ω3) in a spectrophotometric assay. CPT activity increased with the degree of unsaturation and decreased with chain length. CPT activity did not differ between ω3 and ω6 isomers of 18:3, nor was the pattern of CPT substrate preference different between captive white-throated sparrows in a migratory (i.e., displaying Zugunruhe) or non-migratory state. These findings can explain previously observed differences in peak performance induced by dietary fat composition and suggest that lipid supply is limiting to maximal exercise performance in birds.
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Affiliation(s)
- Edwin R Price
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada.
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Price ER. Dietary lipid composition and avian migratory flight performance: Development of a theoretical framework for avian fat storage. Comp Biochem Physiol A Mol Integr Physiol 2010; 157:297-309. [DOI: 10.1016/j.cbpa.2010.05.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 05/31/2010] [Accepted: 05/31/2010] [Indexed: 10/19/2022]
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Guglielmo CG. Move That Fatty Acid: Fuel Selection and Transport in Migratory Birds and Bats. Integr Comp Biol 2010; 50:336-45. [DOI: 10.1093/icb/icq097] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Carvalho JE, Gomes FR, Navas CA. Energy substrate utilization during nightly vocal activity in three species of Scinax (Anura/Hylidae). J Comp Physiol B 2008; 178:447-56. [DOI: 10.1007/s00360-007-0236-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 11/13/2007] [Accepted: 11/30/2007] [Indexed: 11/30/2022]
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McClelland GB. Fat to the fire: the regulation of lipid oxidation with exercise and environmental stress. Comp Biochem Physiol B Biochem Mol Biol 2005; 139:443-60. [PMID: 15544967 DOI: 10.1016/j.cbpc.2004.07.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 07/20/2004] [Accepted: 07/20/2004] [Indexed: 11/22/2022]
Abstract
Lipids are an important fuel for submaximal aerobic exercise. The ways in which lipid oxidation is regulated during locomotion is an area of active investigation. Indeed, the integration between cellular regulation of lipid metabolism and whole-body exercise performance is a fascinating but often overlooked research area. Additionally, the interaction between environmental stress, exercise, and lipid oxidation has not been sufficiently examined. There are many functional and structural steps as fatty acids are mobilized, transported, and oxidized in working muscle, which may serve either as regulatory points for responding to acute or chronic stimuli or as raw material for natural selection. At the whole-animal level, the partitioning of lipids and carbohydrates across exercise intensities is remarkably similar among mammals, which suggests that there is conservation in regulatory mechanisms. Conversely, the proportions of circulatory and intramuscular fuels differ between species and across exercise intensities. Responses to acute and chronic environmental stress likely involve the interaction of genetic and nongenetic changes in the fatty acid pathway. Determining which of these factors help regulate the fatty acid pathway and what impact they have on whole-animal lipid oxidation and performance is an important area of future research. Using an integrative approach to complete the information loop from gene to physiological function provides the most powerful mode of analysis.
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Affiliation(s)
- Grant B McClelland
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, Canada L8S 4K1.
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17
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Belmonte MA, Aoki MS. Triacilglicerol intramuscular: um importante substrato energético para o exercício de endurance. REV BRAS MED ESPORTE 2005. [DOI: 10.1590/s1517-86922005000200008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Os ácidos graxos são uma importante fonte de energia para exercício de endurance. Os ácidos graxos plasmáticos encontram-se disponíveis para as fibras musculares sob a forma de ácidos graxos associados à albumina ou agregados à molécula de triacilglicerol (TAG) encontrada nas lipoproteínas. Entretanto, além dessas fontes plasmáticas, a hidrólise do TAG encontrado no músculo também pode contribuir com a oferta de ácidos graxos durante o exercício de endurance. O objetivo do presente trabalho foi realizar uma extensa revisão da literatura sobre a importância do TAG intramuscular como substrato energético. A revisão da literatura sugere que a contribuição dos estoques endógenos de TAG durante a realização do exercício de endurance é bastante relevante. Além disso, pode-se concluir que uma adaptação induzida pelo treinamento de endurance é o aumento dos estoques intramusculares de TAG. Após o treinamento de endurance, também é observado aumento na capacidade de utilização desses estoques. Apesar de parecer importante, a contribuição do TAG intramuscular ainda é motivo de controvérsia na literatura. Essa discrepância de resultados está relacionada às metodologias empregadas para estimar a sua oxidação no exercício. A fim de esgotar este assunto de maneira apropriada, mais pesquisas, com novos métodos (ex.: utilização de isótopos, ressonância magnética nuclear e microscopia eletrônica), precisam ser conduzidas.
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Guglielmo CG, Haunerland NH, Hochachka PW, Williams TD. Seasonal dynamics of flight muscle fatty acid binding protein and catabolic enzymes in a migratory shorebird. Am J Physiol Regul Integr Comp Physiol 2002; 282:R1405-13. [PMID: 11959683 DOI: 10.1152/ajpregu.00267.2001] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We developed an ELISA to measure heart-type fatty acid binding protein (H-FABP) in muscles of the western sandpiper (Calidris mauri), a long-distance migrant shorebird. H-FABP accounted for almost 11% of cytosolic protein in the heart. Pectoralis H-FABP levels were highest during migration (10%) and declined to 6% in tropically wintering female sandpipers. Premigratory birds increased body fat, but not pectoralis H-FABP, indicating that endurance flight training may be required to stimulate H-FABP expression. Juveniles making their first migration had lower pectoralis H-FABP than adults, further supporting a role for flight training. Aerobic capacity, measured by citrate synthase activity, and fatty acid oxidation capacity, measured by 3-hydroxyacyl-CoA-dehydrogenase and carnitine palmitoyl transferase activities, did not change during premigration but increased during migration by 6, 12, and 13%, respectively. The greater relative induction of H-FABP (+70%) with migration than of catabolic enzymes suggests that elevated H-FABP is related to the enhancement of uptake of fatty acids from the circulation. Citrate synthase, 3-hydroxyacyl-CoA-dehydrogenase, and carnitine palmitoyl transferase were positively correlated within individuals, suggesting coexpression, but enzyme activities were unrelated to H-FABP levels.
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Affiliation(s)
- Christopher G Guglielmo
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6.
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Jessop TS, Knapp R, Whittier JM, Limpus CJ. Dynamic endocrine responses to stress: evidence for energetic constraints and status dependence in breeding male green turtles. Gen Comp Endocrinol 2002; 126:59-67. [PMID: 11944967 DOI: 10.1006/gcen.2001.7769] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During reproduction, male vertebrates may exhibit a continuum of interactions between sex and adrenal steroids during stressful events, the outcome of which may be important in either reducing or promoting male reproductive success. We studied adult male green turtles (Chelonia mydas) to examine if they altered plasma corticosterone (CORT) and androgen levels in response to a standardized capture/restraint stressor as potential mechanisms to maintain reproductive activity during stressful events. At the population level, we found that migrant breeding males had a significantly smaller CORT response to the capture/restraint stressor compared to nonbreeding males and that this decreased response coincided with the generally poorer body condition of migrant breeders. In contrast, plasma androgen levels decreased significantly in response to the capture/restraint stressor in migrant breeding males, but not in nonbreeding and pre-migrant breeding males. For individual migrant breeding males, the magnitude of their CORT and androgen responses to the capture/restraint stressor was highly correlated with their body condition and body length, respectively. Our results demonstrate that male green turtles exhibit complex interactions in their endocrine responses to a capture/restraint stressor and that variation in these interactions is associated with differences in males' reproductive, energetic, and physical state. We hypothesize that interplay between physical status and plasma hormone responses to stressors could have important consequences for male green turtle reproduction.
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Affiliation(s)
- Tim S Jessop
- Department of Zoology, University of Oklahoma, Norman, Oklahoma 73019, USA.
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Ressel SJ. Ultrastructural design of anuran muscles used for call production in relation to the thermal environment of a species. J Exp Biol 2001; 204:1445-57. [PMID: 11273806 DOI: 10.1242/jeb.204.8.1445] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
I examined the aerobic trunk muscles, which are used for call production, of male frogs from species that breed in different thermal environments to test the hypothesis that cold-adapted frogs should have fewer capillaries per unit mitochondrial volume in oxidative muscles than warm-adapted frogs because of reduced mitochondrial function at low temperatures. The species of interest were the cold-temperate Pseudacris crucifer and the warm-tropical Hyla microcephala in the family Hylidae, and the cold-temperate Rana sylvatica and the warm-temperate Rana clamitans in the family Ranidae. Trunk-muscle mitochondrial volume, V(V)(mt,f), was proportionally higher in species with higher mean calling rates (number of notes per hour), irrespective of the familial affinity of a species and the thermal environment in which it vocalized. Trunk-muscle capillary length density, J(V)(c,f), was significantly lower in P. crucifer than in H. microcephala because of significantly higher mean fiber area, a-(f). Conversely, trunk-muscle J(V)(c,f) was similar in the two ranid species. Using total capillary length, J(c), and total mitochondrial volume, V(mt,m), as a measure of maximal oxygen supply and demand, respectively, in trunk muscles, J(c)-to-V(mt,m) ratios were significantly lower in cold-adapted P. crucifer (4.3 km cm(−)(3)) and R. sylvatica (4.8 km cm(−)(3)) than in warm-adapted H. microcephala (7.1 km cm(−)(3)) and R. clamitans (6.4 km cm(−)(3)). In contrast, J(c)-to-V(mt,m) ratios in the more anaerobic gastrocnemius muscle of these species was not related to the thermal environment of a species, which may reflect capillaries conforming to microcirculatory functions, e.g. lactate removal, that take precedence over oxygen delivery. Mitochondrial cristae surface area, S(V)(im,mt), in P. crucifer trunk and gastrocnemius muscles (37.7+/−1.6 and 35.9+/−1.5 m(2)cm(−)(3) respectively) was, on average, similar to mammalian values, suggesting equivalent structural capacities of muscle mitochondria in these two taxa. Taken together, the present data suggest that trunk-muscle respiratory design may reflect a capillary supply commensurate with maximal levels of oxygen delivery set by mitochondria operating at different environmental temperatures. P. crucifer and H. microcephala trunk muscles were also characterized by a high lipid content, which contrasted with a near absence of trunk-muscle lipids in R. sylvatica and R. clamitans. The extraordinarily high lipid content of P. crucifer trunk muscles (26 % of muscle volume) may serve as an auxiliary oxygen pathway to mitochondria and thus compensate in part for this tissue's reduced capillary/fiber interface. The effect of potentially high depletion rates of trunk-muscle lipid stores on metabolic rates of male frogs while calling is discussed.
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Affiliation(s)
- S J Ressel
- Department of Ecology and Evolutionary Biology, U-43, University of Connecticut, Storrs, CT 06269-3043, USA.
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Emerson SB, Hess DL. Glucocorticoids, androgens, testis mass, and the energetics of vocalization in breeding male frogs. Horm Behav 2001; 39:59-69. [PMID: 11161884 DOI: 10.1006/hbeh.2000.1635] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Male advertisement vocalization in frogs is known to be one of the energetically most expensive activities of ectothermic vertebrates. Glucocorticoids have marked effects on energy metabolism, and, generally, plasma concentrations of glucocorticoids increase during the course of prolonged exercise bouts. Androgen concentrations are also known to vary considerably among breeding male frogs. Intraspecific and interspecific comparisons were used to test for a relationship among androgen concentration, corticosterone concentration, testis mass, and the energetics of vocalization in natural populations of calling male frogs. The results of this study indicate that: (1) intraspecific variation in androgen and corticosteroid concentrations in breeding male frogs is positively correlated as a result of both interindividual variation in the amount of performed vocalization and the relationship between calling effort of an individual male and the level of calling in other males, (2) interspecific variation in corticosteroid concentration of calling male frogs is correlated with the relative energy expended in the species-specific vocalization, and (3) when differences in testis mass are controlled for, vocalization effort is correlated with androgen concentration among species of breeding male frogs. These findings are in contrast to some recent work reported from laboratory experiments on calling frogs.
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Affiliation(s)
- S B Emerson
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, Utah 84112, USA
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Torrella J, Fouces V, Palomeque J, Viscor G. Capillarity and fiber types in locomotory muscles of wild common coots,Fulica atra. J Morphol 1998; 237:147-164. [DOI: 10.1002/(sici)1097-4687(199808)237:2<147::aid-jmor6>3.0.co;2-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Guglielmo CG, Haunerland NH, Williams TD. Fatty acid binding protein, a major protein in the flight muscle of migrating western sandpipers. Comp Biochem Physiol B Biochem Mol Biol 1998; 119:549-55. [PMID: 9734338 DOI: 10.1016/s0305-0491(98)00016-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Migratory flight in birds is fueled primarily by fatty acid oxidation imposing a requirement for high rates of fatty acid: (a) transport; (b) uptake; and (c) delivery to intracellular sites of beta-oxidation. Muscle fatty acid binding protein (M-FABP) is a cytosolic protein involved in the intracellular transport of fatty acids. Its expression appears to be correlated with muscle fatty acid oxidation capacity. The M-FABP was isolated for the first time from a long distance migrant bird using: (i) size exclusion; (ii) anion exchange; and (iii) hydroxyapatite chromatography. M-FABP has a molecular weight of approximately 14,000 Da and an isoelectric point of pH 4.8. A partial amino acid sequence of the protein demonstrated homology to M-FABPs from other species (80% identical to human heart FABP). It was estimated that M-FABP comprises approximately 14 and 21% of total cytosolic protein of the pectoralis and heart, respectively; the highest values yet reported from any vertebrate muscle. The abundance of M-FABP in these tissues suggests that the protein may play a key role in fatty acid supply during endurance flight. Thus, it is proposed that a seasonal increase in M-FABP expression could be a component of physiological preparation for migration.
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Affiliation(s)
- C G Guglielmo
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.
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Grafe TU. Energetics of vocalization in the African reed frog (Hyperolius marmoratus). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART A, PHYSIOLOGY 1996; 114:235-43. [PMID: 8759146 DOI: 10.1016/0300-9629(95)02132-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Rates of oxygen consumption and carbon dioxide release were measured in calling and resting painted reed frogs, Hyperolius marmoratus. O2 consumption increased linearly with call rate and reached 0.91 ml/g . h at average call rates of 3100 calls/hr. The respiratory quotient (RQ = VCO2/VO2) was calculated to evaluate which metabolic substrates--lipids or carbohydrates--are utilized. Males that were not fed for a week had significantly lower RQ's during calling (0.75) than recently fed males (0.89) and thus utilized approximately twice as much lipid to fuel calling. Whole-body lipid reserves of males collected in the field varied considerably. Lipid stores alone would be sufficient to provide energy for a median of 15 nights of calling activity at a high density chorus.
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Affiliation(s)
- T U Grafe
- Section of Neurobiology and Behavior, Cornell University, Ithaca, N.Y., USA. . wuerzberg.de
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Carbohydrate and calling: Depletion of muscle glycogen and the chorusing dynamics of the neotropical treefrog Hyla microcephala. Behav Ecol Sociobiol 1995. [DOI: 10.1007/bf00164158] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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