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Kolbe T, Lassnig C, Poelzl A, Palme R, Auer KE, Rülicke T. Effect of Different Ambient Temperatures on Reproductive Outcome and Stress Level of Lactating Females in Two Mouse Strains. Animals (Basel) 2022; 12:ani12162141. [PMID: 36009730 PMCID: PMC9405067 DOI: 10.3390/ani12162141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/16/2022] [Indexed: 11/23/2022] Open
Abstract
Simple Summary The optimal temperature for laboratory mice has been under discussion for some time. Current standard temperature is 20 °C–24 °C but it has been suggested to elevate the standard to 30 °C, which is the thermoneutral zone for mice. In this study, the effect of different cage temperatures (20 °C, 25 °C, 30 °C) on reproduction and stress hormone metabolite excretion was evaluated in lactating females of two commonly used mouse strains. Pup loss was higher, and weights of mothers and pups were reduced at 30 °C compared to the lower temperatures. In addition, pups showed increased tail length at weaning under the high temperature (30 °C). There was no difference in stress hormone metabolite excretion in mice between temperature groups. We could not show any detrimental effects of the lower or higher cage temperature on stress hormone metabolite excretion, but found decreased reproductive outcome under the higher temperature. Abstract Ambient temperature is an important non-biotic environmental factor influencing immunological and oncological parameters in laboratory mice. It is under discussion which temperature is more appropriate and whether the commonly used room temperature in rodent facilities of about 21 °C represents a chronic cold stress or the 30 °C of the thermoneutral zone constitutes heat stress for the animals. In this study, we selected the physiological challenging period of lactation to investigate the influence of a cage temperature of 20 °C, 25 °C, and 30 °C, respectively, on reproductive performance and stress hormone levels in two frequently used mouse strains. We found that B6D2F1 hybrid mothers weaned more pups compared to C57BL/6N mothers, and that the number of weaned pups was reduced when mothers of both strains were kept at 30 °C. Furthermore, at 30 °C, mothers and pups showed reduced body weight at weaning and offspring had longer tails. Despite pronounced temperature effects on reproductive parameters, we did not find any temperature effects on adrenocortical activity in breeding and control mice. Independent of the ambient temperature, however, we found that females raising pups showed elevated levels of faecal corticosterone metabolites (FCMs) compared to controls. Peak levels of stress hormone metabolites were measured around birth and during the third week of lactation. Our results provide no evidence of an advantage for keeping lactating mice in ambient temperatures near the thermoneutral zone. In contrast, we found that a 30 °C cage temperature during lactation reduced body mass in females and their offspring and declined female reproductive performance.
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Affiliation(s)
- Thomas Kolbe
- Biomodels Austria, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
- Department IFA-Tulln, University of Natural Resources and Life Sciences, 1180 Vienna, Austria
- Correspondence:
| | - Caroline Lassnig
- Biomodels Austria, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Andrea Poelzl
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Kerstin E. Auer
- Institute of in vivo and in vitro Models, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Thomas Rülicke
- Department of Biomedical Sciences, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
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2
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Kuroyanagi A, Ukyo R, Kodama Y, Eto T, Okubo Y, Kobayashi I, Ieiri S, Morita T, Sakamoto SH. Body Temperature Measurement Reveals the Reproductive Profile of Female Apodemus speciosus under Laboratory and Field Conditions. MAMMAL STUDY 2022. [DOI: 10.3106/ms2021-0048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Akira Kuroyanagi
- Graduate School of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Rina Ukyo
- Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Yoshinobu Kodama
- Graduate School of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Takeshi Eto
- Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
| | - Yoshinobu Okubo
- Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Ikuo Kobayashi
- Sumiyoshi Livestock Science Station, Field Science Education Research Center, Faculty of Agriculture, University of Miyazaki, Miyazaki 880-0121, Japan
| | - Seiji Ieiri
- Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Tetsuo Morita
- Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
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3
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The effect of reproductive state on activity budget, feeding behavior, and urinary C-peptide levels in wild female Assamese macaques. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03058-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Abstract
The source of maternal energy supporting reproduction (i.e., stored or incoming) is an important factor determining different breeding strategies (capital, income or mixed) in female mammals. Key periods of energy storage and allocation might induce behavioral and physiological shifts in females, and investigating their distribution throughout reproduction helps in determining vulnerable phases shaping female reproductive success. Here, we examined the effects of reproductive state on activity budget, feeding behavior, and urinary C-peptide (uCP) levels, a physiological marker of energy balance, in 43 wild female Assamese macaques (Macaca assamensis). Over a 13-month study period, we collected 96,266 instantaneous records of activity and 905 urine samples. We found that early lactating females and non-gestating–non-lactating females follow an energy-saving strategy consisting of resting more at the expense of feeding and consuming mostly fruits which contributed to enhancing their energy intake and feeding efficiency. We found an opposite pattern in gestating and late lactating females who feed more at the expense of resting and consume mostly seeds, providing a fiber-rich diet. Storing food into cheek pouches increased throughout gestation while it decreased all along with lactation. Lastly, we found the highest uCP levels during late gestation. Our results reflect different feeding adaptations in response to the energetic costs of reproduction and suggest a critical role of fat accumulation before conception and metabolizing fat during gestation and lactation. Overall, our study provides an integrative picture of the energetics of reproduction in a seasonal species and contributes to our understanding of the diversity of behavioral and physiological adaptations shaping female reproductive success.
Significance statement
To offset their substantial energetic investment in reproduction, mammalian females may modify their behavior and the way they extract energy from their environment. In addition, as a result of heightened energy expenditure, female reproduction might trigger physiological shifts. To date, most studies investigated the energetic costs of female reproduction using either a behavioral or a physiological approach. To arrive at a more comprehensive picture, we combined behavioral data with a physiological marker of energy balance, i.e., urinary C-peptide, in a seasonal primate species in its natural habitat. Our results indicate that throughout the reproductive cycle, behavioral and physiological adaptations operate concomitantly, inducing modifications in female activity budget, feeding behavior, and suggesting shifts in fat use. Overall, our results illustrate the relevance of combining data on behavior and hormones to investigate breeding strategies in coping with the energetic costs of reproduction.
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4
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Ohrnberger SA, Hambly C, Speakman JR, Valencak TG. Limits to sustained energy intake. XXXII. Hot again: dorsal shaving increases energy intake and milk output in golden hamsters ( Mesocricetus auratus). J Exp Biol 2020; 223:jeb230383. [PMID: 33188060 DOI: 10.1242/jeb.230383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022]
Abstract
Golden hamsters have four times the body size of mice, raise very large litters and are required to produce large quantities of milk during the 18-day lactation period. We have previously proposed that they may be prone to being limited by their heat dissipation capacity. Studies where lactating females are shaved to elevate their heat dissipation capacity have yielded conflicting data so far. With their short pregnancy of ∼18 days, the large litters and the reported high skin temperatures, they may serve as an ideal model to elucidate the role of epilation for energy budgets in lactating mammals. We shaved one group of lactating females dorsally on the sixth day of lactation, and tested if the elevated heat dissipation capacity would enable them to have higher energy intakes and better food-to-milk conversion rates. Indeed, we observed that females from the shaved group had 6% higher body mass and 0.78°C lower skin temperature than control females during lactation. When focusing on the phase of peak lactation, we observed significantly higher (10%) gross energy intake of food and 23.4% more milk energy output in the shaved females, resulting in 3.3 g higher individual pup weights. We conclude that shaving off the females' fur, even though restricted to the dorsal surface, had large consequences on female energy metabolism in lactation and improved milk production and pup growth in line with our previous work on heat dissipation limitation. Our new data from golden hamsters confirm heat dissipation as a limiting factor for sustained metabolic rate in lactation in some small mammals and emphasise the large effects of a relatively small manipulation such as fur removal on energy metabolism of lactating females.
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Affiliation(s)
- S A Ohrnberger
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
| | - C Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - J R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
- CAS Center of Excellence in Animal Evolution and Genetics, Kunming 650223, China
| | - T G Valencak
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
- College of Animal Sciences, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, 310058 Hangzhou, People's Republic of China
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5
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Xiao Y, Kronenfeld JM, Renquist BJ. Feed intake-dependent and -independent effects of heat stress on lactation and mammary gland development. J Dairy Sci 2020; 103:12003-12014. [PMID: 33041042 DOI: 10.3168/jds.2020-18675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 07/19/2020] [Indexed: 11/19/2022]
Abstract
With a growing population, a reliable food supply is increasingly important. Heat stress reduces livestock meat and milk production. Genetic selection of high-producing animals increases endogenous heat production, while climate change increases exogenous heat exposure. Both sources of heat exacerbate the risk of heat-induced depression of production. Rodents are valuable models to understand mechanisms conserved across species. Heat exposure suppresses feed intake across homeothermic species including rodents and production animal species. We assessed the response to early-mid lactation or late-gestation heat exposure on milk production and mammary gland development/function, respectively. Using pair-fed controls we experimentally isolated the feed intake-dependent and -independent effects of heat stress on mammary function and mass. Heat exposure (35°C, relative humidity 50%) decreased daily feed intake. When heat exposure occurred during lactation, hypophagia accounted for approximately 50% of the heat stress-induced hypogalactia. Heat exposure during middle to late gestation suppressed feed intake, which was fully responsible for the lowered mammary gland weight of dams at parturition. However, the impaired mammary gland function in heat-exposed dams measured by metabolic rate and lactogenesis could not be explained by depressed feed consumption. In conclusion, mice recapitulate the depressed milk production and mammary gland development observed in dairy species while providing insight regarding the role of feed intake. This opens the potential to apply genetic, experimental, and pharmacological models unique to mice to identify the mechanism by which heat is limiting animal production.
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Affiliation(s)
- Yao Xiao
- School of Animal and Comparative Biomedical Science, University of Arizona, Tucson 85721; Department of Animal Sciences, University of Florida, Gainesville 32611
| | - Jason M Kronenfeld
- School of Animal and Comparative Biomedical Science, University of Arizona, Tucson 85721
| | - Benjamin J Renquist
- School of Animal and Comparative Biomedical Science, University of Arizona, Tucson 85721.
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6
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Grattan DR, Ladyman SR. Neurophysiological and cognitive changes in pregnancy. HANDBOOK OF CLINICAL NEUROLOGY 2020; 171:25-55. [PMID: 32736755 DOI: 10.1016/b978-0-444-64239-4.00002-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The hormonal fluctuations in pregnancy drive a wide range of adaptive changes in the maternal brain. These range from specific neurophysiological changes in the patterns of activity of individual neuronal populations, through to complete modification of circuit characteristics leading to fundamental changes in behavior. From a neurologic perspective, the key hormone changes are those of the sex steroids, estradiol and progesterone, secreted first from the ovary and then from the placenta, the adrenal glucocorticoid cortisol, as well as the anterior pituitary peptide hormone prolactin and its pregnancy-specific homolog placental lactogen. All of these hormones are markedly elevated during pregnancy and cross the blood-brain barrier to exert actions on neuronal populations through receptors expressed in specific regions. Many of the hormone-induced changes are in autonomic or homeostatic systems. For example, patterns of oxytocin and prolactin secretion are dramatically altered to support novel physiological functions. Appetite is increased and feedback responses to metabolic hormones such as leptin and insulin are suppressed to promote a positive energy balance. Fundamental physiological systems such as glucose homeostasis and thermoregulation are modified to optimize conditions for fetal development. In addition to these largely autonomic changes, there are also changes in mood, behavior, and higher processes such as cognition. This chapter summarizes the hormonal changes associated with pregnancy and reviews how these changes impact on brain function, drawing on examples from animal research, as well as available information about human pregnancy.
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Affiliation(s)
- David R Grattan
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
| | - Sharon R Ladyman
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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7
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McCarthy R, Jungheim ES, Fay JC, Bates K, Herzog ED, England SK. Riding the Rhythm of Melatonin Through Pregnancy to Deliver on Time. Front Endocrinol (Lausanne) 2019; 10:616. [PMID: 31572299 PMCID: PMC6753220 DOI: 10.3389/fendo.2019.00616] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/27/2019] [Indexed: 12/15/2022] Open
Abstract
Pregnancy is influenced by the circadian ("circa" or approximately; diēm or day) system, which coordinates physiology and behavior with predictable daily changes in the environment such as light/dark cycles. For example, most species deliver around a particular time of day. In mammals, circadian rhythms are controlled by the master circadian pacemaker, the suprachiasmatic nucleus. One key way that the suprachiasmatic nucleus coordinates circadian rhythms throughout the body is by regulating production of the sleep-promoting hormone melatonin. Serum melatonin concentration, which peaks at night and is suppressed during the day, is one of the best biological indicators of circadian timing. Circadian misalignment causes maternal disturbances in the temporal organization of many physiological processes including melatonin synthesis, and these disturbances of the circadian system have been linked to an increased risk for pregnancy complications. Here, we review evidence that melatonin helps regulate the maternal and fetal circadian systems and the timing of birth. Finally, we discuss the potential for melatonin-based therapeutic strategies to alleviate poor pregnancy outcomes such as preeclampsia and preterm birth.
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Affiliation(s)
- Ronald McCarthy
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States
| | - Emily S. Jungheim
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States
| | - Justin C. Fay
- Department of Biology, University of Rochester, Rochester, NY, United States
| | - Keenan Bates
- Department of Biology, Washington University, St. Louis, MO, United States
| | - Erik D. Herzog
- Department of Biology, Washington University, St. Louis, MO, United States
| | - Sarah K. England
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States
- *Correspondence: Sarah K. England
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8
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Ladyman SR, Carter KM, Grattan DR. Energy homeostasis and running wheel activity during pregnancy in the mouse. Physiol Behav 2018; 194:83-94. [PMID: 29738792 DOI: 10.1016/j.physbeh.2018.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/13/2018] [Accepted: 05/04/2018] [Indexed: 01/08/2023]
Abstract
Pregnancy and lactation are metabolically challenging states, where the mother must supply all the energy requirements for the developing fetus and growing pups respectively. The aim of the current study was to characterize many aspects of energy homeostasis before and during pregnancy in the mouse, and to examine the role of voluntary activity on changes in energy expenditure during pregnancy. In a secondary aim, we evaluate measures of energy homeostasis during pregnancy in mice that successfully reared their litter or in mice that went on to abandon their litter, to determine if an impairment in pregnancy-induced adaptation of energy homeostasis might underlie the abandonment of pups soon after birth. During pregnancy, food intake was increased, characterized by increased meal size and duration but not number of meals per day. The duration of time spent inactive, predicted to indicate sleep behaviour, was increased both early and late in pregnancy compared to pre-pregnancy levels. Increased x + y beam breaks, as a measure of activity increased during pregnancy and this reflected an increase in ambulatory behaviour in mid pregnancy and an increase in non-ambulatory movement in late pregnancy. Energy expenditure, as measured by indirect calorimetry, increased across pregnancy, likely due to the growth and development of fetal tissue. There was also a dramatic reduction in voluntary wheel running as soon as the mice became pregnant. Compared with successful pregnancies and lactations, pregnancies where pups were abandoned soon after birth were associated with reduced body weight gain and an increase in running wheel activity at the end of pregnancy, but no difference in food intake or energy expenditure. Overall, during pregnancy there are multiple adaptations to change energy homeostasis, resulting in partitioning of provisions of energy to the developing fetus and storing energy for future metabolic demands.
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Affiliation(s)
- S R Ladyman
- Centre for Neuroendocrinology, Department of Anatomy School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
| | - K M Carter
- Centre for Neuroendocrinology, Department of Anatomy School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - D R Grattan
- Centre for Neuroendocrinology, Department of Anatomy School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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Crew RC, Waddell BJ, Maloney SK, Mark PJ. Diet-induced obesity reduces core body temperature across the estrous cycle and pregnancy in the rat. Chronobiol Int 2018; 35:1077-1087. [PMID: 29659304 DOI: 10.1080/07420528.2018.1458035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Obesity during pregnancy causes adverse maternal and fetal health outcomes and programs offspring for adult-onset diseases, including cardiovascular disease. Obesity also disrupts core body temperature (Tc) regulation in nonpregnant rodents; however, it is unknown whether obesity alters normal maternal Tc adaptations to pregnancy. Since Tc is influenced by the circadian system, and both obesity and pregnancy alter circadian biology, it was hypothesized that obesity disrupts the normal rhythmic patterns of Tc before and during gestation. Obesity was induced by cafeteria (CAF) feeding in female Wistar rats for 8 weeks prior to and during gestation, whereas control (CON) animals had free access to chow. Intraperitoneal temperature loggers measured daily Tc profiles throughout the study, while maternal body composition and leptin levels were assessed near term. Daily temperature profiles were examined for rhythmic features (mesor, amplitude and acrophase) by cosine regression analysis. CAF animals exhibited increased fat mass (93%) and associated hyperleptinemia (3.2-fold increase) compared to CON animals. CAF consumption reduced the average Tc (by up to 0.29°C) across the estrous cycle and most of pregnancy; however, Tc for CAF and CON animals converged toward the end of gestation. Obesity reduced the amplitude of Tc rhythms at estrus and proestrus and on day 8 of pregnancy, but increased the amplitude at day 20 of pregnancy. Photoperiod analysis revealed that obesity reduced Tc exclusively in the light period during pre-pregnancy but only during the dark period in late gestation. In conclusion, obesity alters rhythmic Tc profiles and reduces the magnitude of the Tc decline late in rat gestation, which may have implications for maternal health and fetal development.
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Affiliation(s)
- Rachael C Crew
- a School of Human Sciences , The University of Western Australia , Perth , Australia
| | - Brendan J Waddell
- a School of Human Sciences , The University of Western Australia , Perth , Australia
| | - Shane K Maloney
- a School of Human Sciences , The University of Western Australia , Perth , Australia
| | - Peter J Mark
- a School of Human Sciences , The University of Western Australia , Perth , Australia
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10
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Ohrnberger SA, Brinkmann K, Palme R, Valencak TG. Dorsal shaving affects concentrations of faecal cortisol metabolites in lactating golden hamsters. Naturwissenschaften 2018; 105:13. [PMID: 29335818 PMCID: PMC5769818 DOI: 10.1007/s00114-017-1536-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/20/2017] [Accepted: 12/22/2017] [Indexed: 11/04/2022]
Abstract
Breeding of golden hamsters is classically performed at thermal conditions ranging from 20 to 24 °C. However, growing evidence suggests that lactating females suffer from heat stress. We hypothesised that shaving females dorsally to maximise heat dissipation may reduce stress during reproduction. We thus compared faecal cortisol metabolites (FCM) from shaved golden hamster mothers with those from unshaved controls. We observed significantly lower FCM levels in the shaved mothers (F1,22 = 8.69, p = 0.0075) pointing to lower stress due to ameliorated heat dissipation over the body surface. In addition, we observed 0.4 °C lower mean subcutaneous body temperatures in the shaved females, although this effect did not reach significance (F1,22 = 1.86, p = 0.18). Our results suggest that golden hamsters having body masses being more than four times that of laboratory mice provide a very interesting model to study aspects of lactation and heat production at the same time.
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Affiliation(s)
- Sarah A Ohrnberger
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Katharina Brinkmann
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Rupert Palme
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Teresa G Valencak
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
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11
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Mark PJ, Crew RC, Wharfe MD, Waddell BJ. Rhythmic Three-Part Harmony: The Complex Interaction of Maternal, Placental and Fetal Circadian Systems. J Biol Rhythms 2017; 32:534-549. [PMID: 28920512 DOI: 10.1177/0748730417728671] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
From the perspective of circadian biology, mammalian pregnancy presents an unusual biological scenario in which an entire circadian system (i.e., that of the fetus) is embodied within another (i.e., that of the mother). Moreover, both systems are likely to be influenced at their interface by a third player, the placenta. Successful pregnancy requires major adaptations in maternal physiology, many of which involve circadian changes that support the high metabolic demands of the growing fetus. A functional role for maternal circadian adaptations is implied by the effects of circadian disruption, which result in pregnancy complications including higher risks for miscarriage, preterm labor, and low birth weight. Various aspects of fetal physiology lead to circadian variation, at least in late gestation, but it remains unclear what drives this rhythmicity. It likely involves contributions from the maternal environment and possibly from the placenta and the developing intrinsic molecular clocks within fetal tissues. The role of the placenta is of particular significance because it serves not only to relay signals about the external environment (via the mother) but may also exhibit its own circadian rhythmicity. This review considers how the fetus may be influenced by dynamic circadian signals from the mother and the placenta during gestation, and how, in the face of these changing influences, a new fetal circadian system emerges. Particular emphasis is placed on the role of endocrine signals, most notably melatonin and glucocorticoids, as mediators of maternal-fetal circadian interactions, and on the expression of the clock gene in the 3 compartments. Further study is required to understand how the mother, placenta, and fetus interact across pregnancy to optimize circadian adaptations that support adequate growth and development of the fetus and its transition to postnatal life in a circadian environment.
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Affiliation(s)
- Peter J Mark
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Rachael C Crew
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Michaela D Wharfe
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Brendan J Waddell
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
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12
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Gellén B, Zelena D, Usdin TB, Dobolyi Á. The parathyroid hormone 2 receptor participates in physiological and behavioral alterations of mother mice. Physiol Behav 2017; 181:51-58. [PMID: 28890271 DOI: 10.1016/j.physbeh.2017.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/06/2017] [Accepted: 09/06/2017] [Indexed: 11/18/2022]
Affiliation(s)
- Barbara Gellén
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, Hungary
| | - Dóra Zelena
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
| | - Ted B Usdin
- Section on Fundamental Neuroscience, National Institute of Mental Health, NIH, Bethesda, MD, USA
| | - Árpád Dobolyi
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, Hungary; Laboratory of Neuromorphology and Human Brain Tissue Bank, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary.
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13
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Wharfe MD, Wyrwoll CS, Waddell BJ, Mark PJ. Pregnancy Suppresses the Daily Rhythmicity of Core Body Temperature and Adipose Metabolic Gene Expression in the Mouse. Endocrinology 2016; 157:3320-31. [PMID: 27409644 DOI: 10.1210/en.2016-1177] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Maternal adaptations in lipid metabolism are crucial for pregnancy success due to the role of white adipose tissue as an energy store and the dynamic nature of energy needs across gestation. Because lipid metabolism is regulated by the rhythmic expression of clock genes, it was hypothesized that maternal metabolic adaptations involve changes in both adipose clock gene expression and the rhythmic expression of downstream metabolic genes. Maternal core body temperature (Tc) was investigated as a possible mechanism driving pregnancy-induced changes in clock gene expression. Gonadal adipose tissue and plasma were collected from C57BL/6J mice before and on days 6, 10, 14, and 18 of pregnancy (term 19 d) at 4-hour intervals across a 24-hour period. Adipose expression of clock genes and downstream metabolic genes were determined by quantitative RT-PCR, and Tc was measured by intraperitoneal temperature loggers. Adipose clock gene expression showed robust rhythmicity throughout pregnancy, but absolute levels varied substantially across gestation. Rhythmic expression of the metabolic genes Lipe, Pnpla2, and Lpl was clearly evident before pregnancy; however, this rhythmicity was lost with the onset of pregnancy. Tc rhythm was significantly altered by pregnancy, with a 65% decrease in amplitude by term and a 0.61°C decrease in mesor between days 6 and 18. These changes in Tc, however, did not appear to be linked to adipose clock gene expression across pregnancy. Overall, our data show marked adaptations in the adipose clock in pregnancy, with an apparent decoupling of adipose clock and lipolytic/lipogenic gene rhythms from early in gestation.
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Affiliation(s)
- Michaela D Wharfe
- School of Anatomy, Physiology, and Human Biology, The University of Western Australia, Perth 6009, Australia
| | - Caitlin S Wyrwoll
- School of Anatomy, Physiology, and Human Biology, The University of Western Australia, Perth 6009, Australia
| | - Brendan J Waddell
- School of Anatomy, Physiology, and Human Biology, The University of Western Australia, Perth 6009, Australia
| | - Peter J Mark
- School of Anatomy, Physiology, and Human Biology, The University of Western Australia, Perth 6009, Australia
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Chi QS, Wan XR, Geiser F, Wang DH. Fasting-induced daily torpor in desert hamsters (Phodopus roborovskii). Comp Biochem Physiol A Mol Integr Physiol 2016; 199:71-77. [PMID: 27215346 DOI: 10.1016/j.cbpa.2016.05.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 05/12/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
Abstract
Daily torpor is frequently expressed in small rodents when facing energetically unfavorable ambient conditions. Desert hamsters (Phodopus roborovskii, ~20g) appear to be an exception as they have been described as homeothermic. However, we hypothesized that they can use torpor because we observed reversible decreases of body temperature (Tb) in fasted hamsters. To test this hypothesis we (i) randomly exposed fasted summer-acclimated hamsters to ambient temperatures (Tas) ranging from 5 to 30°C or (ii) supplied them with different rations of food at Ta 23°C. All desert hamsters showed heterothermy with the lowest mean Tb of 31.4±1.9°C (minimum, 29.0°C) and 31.8±2.0°C (minimum, 29.0°C) when fasted at Ta of 23°C and 19°C, respectively. Below Ta 19°C, the lowest Tb and metabolic rate increased and the proportion of hamsters using heterothermy declined. At Ta 5°C, nearly all hamsters remained normothermic by increasing heat production, suggesting that the heterothermy only occurs in moderately cold conditions, perhaps to avoid freezing at extremely low Tas. During heterothermy, Tbs below 31°C with metabolic rates below 25% of those during normothermia were detected in four individuals at Ta of 19°C and 23°C. Consequently, by definition, our observations confirm that fasted desert hamsters are capable of shallow daily torpor. The negative correlation between the lowest Tbs and amount of food supply shows that heterothermy was mainly triggered by food shortage. Our data indicate that summer-acclimated desert hamsters can express fasting-induced shallow daily torpor, which may be of significance for energy conservation and survival in the wild.
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Affiliation(s)
- Qing-Sheng Chi
- State Key Laboratory of Integrated Management for Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xin-Rong Wan
- State Key Laboratory of Integrated Management for Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, New South Wales 2351, Australia
| | - De-Hua Wang
- State Key Laboratory of Integrated Management for Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
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15
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Książek A, Konarzewski M. Heat dissipation does not suppress an immune response in laboratory mice divergently selected for basal metabolic rate (BMR). ACTA ACUST UNITED AC 2016; 219:1542-51. [PMID: 26944492 DOI: 10.1242/jeb.129312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 03/01/2016] [Indexed: 01/01/2023]
Abstract
The capacity for heat dissipation is considered to be one of the most important constraints on rates of energy expenditure in mammals. To date, the significance of this constraint has been tested exclusively under peak metabolic demands, such as during lactation. Here, we used a different set of metabolic stressors, which do not induce maximum energy expenditures and yet are likely to expose the potential constraining effect of heat dissipation. We compared the physiological responses of mice divergently selected for high (H-BMR) and low basal metabolic rate (L-BMR) to simultaneous exposure to the keyhole limpet haemocyanin (KLH) antigen and high ambient temperature (Ta). At 34°C (and at 23°C, used as a control), KLH challenge resulted in a transient increase in core body temperature (Tb) in mice of both line types (by approximately 0.4°C). Warm exposure did not produce line-type-dependent differences in Tb (which was consistently higher by ca. 0.6°C in H-BMR mice across both Ta values), nor did it result in the suppression of antibody synthesis. These findings were also supported by the lack of between-line-type differences in the mass of the thymus, spleen or lymph nodes. Warm exposure induced the downsizing of heat-generating internal organs (small intestine, liver and kidneys) and an increase in intrascapular brown adipose tissue mass. However, these changes were similar in scope in both line types. Mounting a humoral immune response in selected mice was therefore not affected by ambient temperature. Thus, a combined metabolic challenge of high Ta and an immune response did not appreciably compromise the capacity to dissipate heat, even in the H-BMR mice.
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Affiliation(s)
- Aneta Książek
- Institute of Biology, University of Białystok, Ciołkowskiego 1J, Białystok 15-245, Poland
| | - Marek Konarzewski
- Institute of Biology, University of Białystok, Ciołkowskiego 1J, Białystok 15-245, Poland
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16
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Gamo Y, Bernard A, Troup C, Munro F, Derrer K, Jeannesson N, Campbell A, Gray H, Miller J, Dixon J, Mitchell SE, Hambly C, Vaanholt LM, Speakman JR. Limits to sustained energy intake XXIV: impact of suckling behaviour on the body temperatures of lactating female mice. Sci Rep 2016; 6:25665. [PMID: 27157478 PMCID: PMC4860708 DOI: 10.1038/srep25665] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/06/2016] [Indexed: 11/29/2022] Open
Abstract
The objective of this study was to investigate the potential causes of high body temperature (Tb) during lactation in mice as a putative limit on energy intake. In particular we explored whether or not offspring contributed to heat retention in mothers while suckling. Tb and physical activity were monitored in 26 female MF1 mice using intraperitoneally implanted transmitters. In addition, maternal behaviour was scored each minute for 8 h d(-1) throughout lactation. Mothers that raised larger litters tended to have higher Tb while nursing inside nests (P < 0.05), suggesting that nursing offspring may have influenced heat retention. However, Tb during nursing was not higher than that recorded during other behaviours. In addition, the highest Tb during the observation period was not measured during nursing behaviour. Finally, there was no indication that mothers discontinued suckling because of a progressive rise in their Tb while suckling. Tb throughout lactation was correlated with daily increases in energy intake. Chronic hyperthermia during lactation was not caused by increased heat retention due to surrounding offspring. Other factors, like metabolic heat produced as a by-product of milk production or energy intake may be more important factors. Heat dissipation limits are probably not a phenomenon restricted to lactation.
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Affiliation(s)
- Y. Gamo
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - A. Bernard
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - C. Troup
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - F. Munro
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - K. Derrer
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - N. Jeannesson
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - A. Campbell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - H. Gray
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - J. Miller
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - J. Dixon
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - S. E. Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - C. Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - L. M. Vaanholt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - J. R. Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beichen Xi Lu, Chaoyang, Beijing, People’s Republic of China
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17
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Sadowska ET, Król E, Chrzascik KM, Rudolf AM, Speakman JR, Koteja P. Limits to sustained energy intake. XXIII. Does heat dissipation capacity limit the energy budget of lactating bank voles? ACTA ACUST UNITED AC 2016; 219:805-15. [PMID: 26747907 DOI: 10.1242/jeb.134437] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/28/2015] [Indexed: 01/13/2023]
Abstract
Understanding factors limiting sustained metabolic rate (SusMR) is a central issue in ecological physiology. According to the heat dissipation limit (HDL) theory, the SusMR at peak lactation is constrained by the maternal capacity to dissipate body heat. To test that theory, we shaved lactating bank voles (Myodes glareolus) to experimentally elevate their capacity for heat dissipation. The voles were sampled from lines selected for high aerobic exercise metabolism (A; characterized also by increased basal metabolic rate) and unselected control lines (C). Fur removal significantly increased the peak-lactation food intake (mass-adjusted least square means ± s.e.; shaved: 16.3 ± 0.3 g day(-1), unshaved: 14.4 ± 0.2 g day(-1); P<0.0001), average daily metabolic rate (shaved: 109 ± 2 kJ day(-1), unshaved: 97 ± 2 kJ day(-1); P<0.0001) and metabolisable energy intake (shaved: 215 ± 4 kJ day(-1), unshaved: 185 ± 4 kJ day(-1); P<0.0001), as well as the milk energy output (shaved: 104 ± 4 kJ day(-1); unshaved: 93 ± 4 kJ day(-1); P=0.021) and litter growth rate (shaved: 9.4 ± 0.7 g 4 days(-1), unshaved: 7.7 ± 0.7 g 4 days(-1); P=0.028). Thus, fur removal increased both the total energy budget and reproductive output at the most demanding period of lactation, which supports the HDL theory. However, digestive efficiency was lower in shaved voles (76.0 ± 0.3%) than in unshaved ones (78.5 ± 0.2%; P<0.0001), which may indicate that a limit imposed by the capacity of the alimentary system was also approached. Shaving similarly affected the metabolic and reproductive traits in voles from the A and C lines. Thus, the experimental evolution model did not reveal a difference in the limiting mechanism between animals with inherently different metabolic rates.
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Affiliation(s)
- Edyta T Sadowska
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
| | - Elżbieta Król
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Katarzyna M Chrzascik
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
| | - Agata M Rudolf
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beichen Xi Lu, Chaoyang, Beijing 100101, People's Republic of China
| | - Paweł Koteja
- Institute of Environmental Sciences, Jagiellonian University, ul. Gronostajowa 7, Kraków 30-387, Poland
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18
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Speakman JR, Al-Jothery AH, Król E, Hawkins J, Chetoui A, Saint-Lambert A, Gamo Y, Shaw SC, Valencak T, Bünger L, Hill W, Vaanholt L, Hambly C. Limits to sustained energy intake. XXII. Reproductive performance of two selected mouse lines with different thermal conductance. J Exp Biol 2014; 217:3718-32. [DOI: 10.1242/jeb.103705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Abstract
Maximal sustained energy intake (SusEI) appears limited, but the factors imposing the limit are disputed. We studied reproductive performance in two lines of mice selected for high and low food intake (MH and ML, respectively), and known to have large differences in thermal conductance (29% higher in the MH line at 21°C). When these mice raised their natural litters, their metabolisable energy intake significantly increased over the first 13 days of lactation and then reached a plateau. At peak lactation, MH mice assimilated on average 45.3 % more energy than ML mice (222.9±7.1 and 153.4±12.5 kJ day-1, N=49 and 24, respectively). Moreover, MH mice exported on average 62.3 kJ day-1 more energy as milk than ML mice (118.9±5.3 and 56.6±5.4 kJ day-1, N= subset of 32 and 21, respectively). The elevated milk production of MH mice enabled them to wean litters (65.2±2.1 g) that were on average 50.2% heavier than litters produced by ML mothers (43.4±3.0 g), and pups that were on average 27.2% heavier (9.9±0.2 and 7.8±0.2 g, respectively). Lactating mice in both lines had significantly longer and heavier guts compared to non-reproductive mice. However, inconsistent with the central limit hypothesis, the ML mice had significantly longer and heavier intestines than MH mice. An experiment where the mice raised litters of the opposing line demonstrated that lactation performance was not limited by offspring growth capacity. Our findings are consistent with the idea that the SusEI at peak lactation is constrained by the capacity of the mothers to dissipate body heat.
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Affiliation(s)
| | | | | | | | | | | | - Yuko Gamo
- University of Aberdeen, United Kingdom
| | | | | | - Lutz Bünger
- Scotland's Rural College (SRUC), United Kingdom
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19
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Speakman JR, Garratt M. Oxidative stress as a cost of reproduction: Beyond the simplistic trade-off model. Bioessays 2013; 36:93-106. [DOI: 10.1002/bies.201300108] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- John R. Speakman
- Key State Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
- Institute of Biological and Environmental sciences; University of Aberdeen; Aberdeen Scotland UK
| | - Michael Garratt
- Evolution and Ecology Research Group and School of Biological, Earth and Environmental Sciences; The University of New South Wales; Sydney NSW Australia
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20
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Valencak TG, Wright P, Weir A, Mitchell SE, Vaanholt LM, Hambly C, Król E, Speakman JR. Limits to sustained energy intake. XXI. Effect of exposing the mother, but not her pups, to a cold environment during lactation in mice. ACTA ACUST UNITED AC 2013; 216:4326-33. [PMID: 23997194 DOI: 10.1242/jeb.092023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The capacity of females to dissipate heat may constrain sustained energy intake during lactation. However, some previous experiments supporting this concept have confounded the impact of temperature on the mothers with the impact on the pups. We aimed to separate these effects in lactating laboratory mice (MF1 strain) by giving the mothers access to cages at two ambient temperatures (10 and 21°C) joined by a tube. Food was available only in the cold cage, but females could also choose go to this cage to cool down while their pups were housed in the warmer cage. Control animals had access to the same configuration of cages but with both maintained at 21°C. We hypothesised that if females were limited by heat dissipation, alleviating the heat load by providing a cool environment would allow them to dissipate more heat, take in more food, generate more milk and hence wean heavier litters. We measured maternal energy budgets and monitored time courses of core body temperature and physical activity. To minimise the variance in energy budgets, all litters were adjusted to 12 (±1) pups. Females in the experimental group had higher energy intake (F1,14=15.8, P=0.0014) and higher assimilated energy (F1,13=10.7, P=0.006), and provided their pups with more milk (F1,13=6.65, P=0.03), consistent with the heat dissipation limit theory. Yet, despite keeping demand constant, mean pup growth rates were similar (F1,13=0.06, P=0.8); thus, our data emphasise the difficulties of inferring milk production indirectly from pup growth.
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Affiliation(s)
- Teresa G Valencak
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beichen Xi Lu, Chaoyang, 100101 Beijing, People's Republic of China
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21
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Gamo Y, Troup C, Mitchell SE, Hambly C, Vaanholt LM, Speakman JR. Limits to sustained energy intake. XX. Body temperatures and physical activity of female mice during lactation. ACTA ACUST UNITED AC 2013; 216:3751-61. [PMID: 23788704 DOI: 10.1242/jeb.090308] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Lactating animals consume greater amounts of food than non-reproductive animals, but energy intake appears to be limited in late lactation. The heat dissipation limit theory suggests that the food intake of lactating mice is limited by the capacity of the mother to dissipate heat. Lactating mice should therefore have high body temperatures (Tb), and changes in energy intake during lactation should be reflected by variation in Tb. To investigate these predictions, 26 mice (Mus musculus) were monitored daily throughout lactation for food intake, body mass, litter size and litter mass. After weaning, 21 days postpartum, maternal food intake and body mass were monitored for another 10 days. Maternal activity and Tb were recorded every minute for 23 h a day using implanted transmitters (vital view). Energy intake increased to a plateau in late lactation (days 13-17). Daily gain in pup mass declined during this same period, suggesting a limit on maternal energy intake. Litter size and litter mass were positively related to maternal energy intake and body mass. Activity levels were constantly low, and mice with the largest increase in energy intake at peak lactation had the lowest activity. Tb rose sharply after parturition and the circadian rhythm became compressed within a small range. Tb during the light period increased considerably (1.1 ° C higher than in baseline), and lactating mice faced chronic hyperthermia, despite their activity levels in lactation being approximately halved. Average Tb increased in relation to energy intake as lactation progressed, but there was no relationship between litter size or litter mass and the mean Tb at peak lactation. These data are consistent with the heat dissipation limit theory, which suggests performance in late lactation is constrained by the ability to dissipate body heat.
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Affiliation(s)
- Y Gamo
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
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22
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Stead N. SUSTAINED ENERGY INTAKE DEBATE GETS MORE COMPLEX. J Exp Biol 2013. [DOI: 10.1242/jeb.089235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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23
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Duah OA, Monney KA, Hambly C, Król E, Speakman JR. Limits to sustained energy intake. XVII. Lactation performance in MF1 mice is not programmed by fetal number during pregnancy. J Exp Biol 2013; 216:2339-48. [DOI: 10.1242/jeb.078428] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
SUMMARY
Several studies have suggested that lactation performance may be programmed by the number of fetuses during pregnancy, whereas other studies indicate that processes during lactation are more important. As gestation litter size and litter size in lactation are usually strongly correlated, separating the roles of pregnancy and lactation in lactation performance is difficult. To break this link, we experimentally manipulated litter size of MF1 mice to five or 16 pups per litter by cross-fostering. Litter size and mass at birth were recorded on day 1 of lactation prior to litter size manipulation. Maternal body mass and food intake, litter size and litter mass were measured daily throughout. After weaning, the potential differential utilisation of body tissues of the mothers was investigated. Relationships between maternal mass and food intake, including asymptotic daily food intake at peak lactation, offspring traits and other maternal parameters suggested that the number of fetuses the females had carried during pregnancy had no effect on lactation performance. Litter mass increases depended only on maternal food intake, which was highly variable between individuals, but was independent of fetal litter size. The sizes of key organs and tissues like the liver and alimentary tract were not related to maximal food intake at peak lactation or to fetal litter size, but the masses of the pelage, mammary glands and retroperitoneal fat pad were. These data suggest that while growth of the mammary glands and associated structures may be initiated in gestation, and vary in relation to the number of placentas, the ultimate sizes and activities of the tissues depends primarily on factors during lactation.
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Affiliation(s)
- Osei A. Duah
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - Kweku A. Monney
- School of Biological Sciences, Department of Entomology and Wildlife, University of Cape Coast, Cape Coast, Ghana
| | - Catherine Hambly
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - Elzbieta Król
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- Mammal Research Institute PAS, 17-230 Białowieża, Poland
| | - John R. Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beichen Xi Lu, Chaoyang, Beijing 100101, People's Republic of China
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24
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Zhao ZJ, Król E, Moille S, Gamo Y, Speakman JR. Limits to sustained energy intake. XV. Effects of wheel running on the energy budget during lactation. J Exp Biol 2013; 216:2316-27. [DOI: 10.1242/jeb.078402] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SUMMARY
The capacity of animals to dissipate heat may constrain sustained energy intake during lactation. We examined these constraints at peak lactation in MF1 mice that had ad libitum access to food, or that had to run a pre-set target on running wheels to obtain ad libitum access to food. The voluntary distance run decreased sharply during pregnancy and peak lactation. When lactating females were provided with 80% of their estimated food requirements, and had to run pre-set distances of 2, 4 or 6 km before given access to additional ad libitum food, most of them did not complete the running target during late lactation and the mice with the highest targets failed to reach their targets earlier in lactation. There were consequently significant group differences in asymptotic food intake (2 km, 16.97±0.40 g day−1; 4 km, 14.29±0.72 g day−1; and 6 km, 12.65±0.45 g day−1) and weaned litter masses (2 km, 71.11±2.39 g; 4 km, 54.63±4.28 g and 6 km, 47.18±2.46 g). When the females did run sufficiently to gain ad libitum food access, their intake did not differ between the different distance groups or from controls that were not required to run. Thus, despite being physically capable of running the distances, mice could not exercise sufficiently in lactation to gain regular ad libitum access to food, probably because of the risks of hyperthermia when combining heat production from exercise with thermogenesis from lactation.
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Affiliation(s)
- Zhi-Jun Zhao
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou 325027, People's Republic of China
| | - Elzbieta Król
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- Mammal Research Institute PAS, 17-230 Białowieża, Poland
| | - Sophie Moille
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - Yuko Gamo
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - John R. Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- Institute of Genetics and Developmental Biology, State Key Laboratory of Molecular Developmental Biology, Chinese Academy of Sciences, Beichen Xi Lu, Chaoyang, Beijing 100101, People's Republic of China
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25
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Yang DB, Li L, Wang LP, Chi QS, Hambly C, Wang DH, Speakman JR. Limits to sustained energy intake. XIX. A test of the heat dissipation limitation hypothesis in Mongolian gerbils (Meriones unguiculatus). ACTA ACUST UNITED AC 2013; 216:3358-68. [PMID: 23737554 DOI: 10.1242/jeb.085233] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We evaluated factors limiting lactating Mongolian gerbils (Meriones unguiculatus) at three temperatures (10, 21 and 30°C). Energy intake and daily energy expenditure (DEE) increased with decreased ambient temperature. At peak lactation (day 14 of lactation), energy intake increased from 148.7±5.7 kJ day(-1) at 30°C to 213.1±8.2 kJ day(-1) at 21°C and 248.7±12.3 kJ day(-1) at 10°C. DEE increased from 105.1±4.0 kJ day(-1) at 30°C to 134.7±5.6 kJ day(-1) at 21°C and 179.5±8.4 kJ day(-1) at 10°C on days 14-16 of lactation. With nearly identical mean litter sizes, lactating gerbils at 30°C exported 32.0 kJ day(-1) less energy as milk at peak lactation than those allocated to 10 or 21°C, with no difference between the latter groups. On day 14 of lactation, the litter masses at 10 and 30°C were 12.2 and 9.3 g lower than those at 21°C, respectively. Lactating gerbils had higher thermal conductance of the fur and lower UCP-1 levels in brown adipose tissue than non-reproductive gerbils, independent of ambient temperature, suggesting that they were attempting to avoid heat stress. Thermal conductance of the fur was positively related to circulating prolactin levels. We implanted non-reproductive gerbils with mini-osmotic pumps that delivered either prolactin or saline. Prolactin did not influence thermal conductance of the fur, but did reduce physical activity and UCP-1 levels in brown adipose tissue. Transferring lactating gerbils from warm to hot conditions resulted in reduced milk production, consistent with the heat dissipation limit theory, but transferring them from warm to cold conditions did not elevate milk production, consistent with the peripheral limitation hypothesis, and placed constraints on pup growth.
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Affiliation(s)
- Deng-Bao Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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