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López-Arjona M, Cerón JJ, Mateo SV, Contreras-Aguilar MD, Martínez-Subiela S. Validation of two immunoassays for oxytocin measurements in human saliva. PLoS One 2024; 19:e0297539. [PMID: 38635553 PMCID: PMC11025789 DOI: 10.1371/journal.pone.0297539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/09/2024] [Indexed: 04/20/2024] Open
Abstract
The objective of this research was to develop and validate two immunoassays for oxytocin measurement in human saliva, one using a monoclonal and the other a polyclonal antibody against oxytocin, whose affinity for oxytocin was tested by an antibody mapping epitope analysis. These assays were analytically validated and used to compare oxytocin concentrations with those obtained with a commercial kit before and after the extraction or reduction/alkylation (R/A) treatments to saliva samples. The assays were also used to evaluate changes in salivary oxytocin concentrations following a physical effort and an induced psychological stress, which have previously been described as situations that cause an increase in salivary oxytocin. Both assays showed to be precise and accurate in the validation studies, and the antibodies used showed a defined binding region in case of the monoclonal antibody, whereas the polyclonal antibody showed binding events through all the oxytocin sequence. Although the monoclonal and polyclonal assays showed a positive correlation, they give results in a different range of magnitude. Both assays showed significant increases in oxytocin concentrations when applied after the physical effort and the psychological stress. This study shows that a variability in the reported values of oxytocin can occur depending on the assay and indicates that the use of different types of antibodies can give a different range of values when measuring oxytocin in saliva.
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Affiliation(s)
- Marina López-Arjona
- Department of Animal and Food Science, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - José Joaquín Cerón
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Regional Campus of International Excellence ‘Campus Mare Nostrum’, University of Murcia, Murcia, Spain
| | - Sandra V. Mateo
- Molecular Inflammation Group, University Clinical Hospital Virgen de la Arrixaca, Biomedical Research Institute of Murcia (IMIB-Pascual Parrilla), Murcia, Spain
| | - María Dolores Contreras-Aguilar
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Regional Campus of International Excellence ‘Campus Mare Nostrum’, University of Murcia, Murcia, Spain
| | - Silvia Martínez-Subiela
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Regional Campus of International Excellence ‘Campus Mare Nostrum’, University of Murcia, Murcia, Spain
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Moscovice LR, Sobczak B, Niittynen T, Koski SE, Gimsa U. Changes in salivary oxytocin in response to biologically-relevant events in farm animals: method optimization and usefulness as a biomarker. Front Physiol 2024; 15:1370557. [PMID: 38567114 PMCID: PMC10985263 DOI: 10.3389/fphys.2024.1370557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 02/21/2024] [Indexed: 04/04/2024] Open
Abstract
Although best known for its established role in mediating parturition and lactation, the highly-conserved neuropeptide hormone oxytocin also mediates a range of social and stress-buffering processes across mammalian species. Measurements of peripheral oxytocin in plasma have long been considered the gold standard, but there is increasing interest in developing methods to detect oxytocin non-invasively in saliva. Here we present an analytical and biological validation of a novel method to measure salivary oxytocin (sOXT) in an under-studied research group: farm animals. Given their similarities with humans in physiology and brain, methods that can identify valued social contexts and social relationships for farm animals and investigate their function have implications for clinical research as well as for animal welfare science. However, current methods to measure sOXT vary greatly in terms of sample collection, pre-measurement processing and measurement and more rigorous standardization and validation of methods is critical to determine the utility of sOXT as a biomarker of salient social events and related emotions. We optimized a method for extracting sOXT in pigs and horses and measured sOXT in extracted samples using a commercially available enzyme-immunoassay. Extracted samples were within acceptable ranges for precision (CVs < 15.2%), parallelism and recovery (94%-99%) in both species. Salivary oxytocin increased in samples collected during birth in pigs (Friedmans, p = 0.02) and horses (Wilcoxon, p = 0.02). Salivary oxytocin tended to decrease in sows after a 90-min separation from their piglets (Wilcoxon, p = 0.08). We conclude that sOXT can be reliably linked to physiological events that are mediated by the oxytocinergic system in farm animals, but that more research is needed to determine whether sOXT is a reliable trait marker for more general oxytocin system activation in response to salient social events. Future research should characterize how individual attributes and salivary parameters influence sOXT measurement and should emphasize reporting of analytical and biological validations to increase acceptance of non-invasive methods.
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Affiliation(s)
- Liza R. Moscovice
- Psychophysiology Working Group, Research Institute for Farm Animal Biology, Dummerstorf, Germany
| | - Birgit Sobczak
- Psychophysiology Working Group, Research Institute for Farm Animal Biology, Dummerstorf, Germany
| | - Taru Niittynen
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Sonja E. Koski
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Ulrike Gimsa
- Psychophysiology Working Group, Research Institute for Farm Animal Biology, Dummerstorf, Germany
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Berget B, Vas J, Pedersen G, Uvnäs-Moberg K, Newberry RC. Oxytocin levels and self-reported anxiety during interactions between humans and cows. Front Psychol 2023; 14:1252463. [PMID: 37780173 PMCID: PMC10536144 DOI: 10.3389/fpsyg.2023.1252463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 09/01/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction Positive social interactions with farm animals may have therapeutic benefits on humans by increasing brain oxytocin secretion, as inferred from circulating oxytocin levels. The aim of this observational study was to investigate acute changes in human plasma oxytocin levels and state anxiety associated with interactions with dairy cows. Methods Data were collected from 18 healthy female nursing students who performed stroking and brushing of an unfamiliar cow for 15 min. Blood samples were drawn before entering the cowshed (T1, baseline), and after 5 (T2) and 15 (T3) min of interaction with a cow. At T1 and T3, the students filled out the Norwegian version of the Spielberger State-Trait Anxiety Inventory-State Subscale (STAI-SS). Results Across participants, no significant changes in average plasma oxytocin concentration were detected between time points (p>0.05). There was, however, a modest decline in the STAI-SS scores between T1 and T3 (p=0.015) and a positive correlation between the change in individual level of state anxiety between T1 and T3 and the change in OT concentration of the same individual between T2 and T3 (p = 0.045). Discussion The results suggest that friendly social interactions with cows are beneficial in lowering state anxiety, but any relationship with release of OT into the circulation was complex and variable across individuals. The acute reduction in state anxiety lends support to the value of interacting with farm animals in the context of Green Care for people with mental health challenges.
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Affiliation(s)
- Bente Berget
- Faculty of Health and Social Sciences, Department of Health, Social and Welfare Studies, University of South-Eastern Norway, Borre, Norway
- Department of Health and Society, NORCE Norwegian Research Centre AS, Kristiansand, Norway
| | - Judit Vas
- Faculty of Biosciences, Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Gunn Pedersen
- Faculty of Biosciences, Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Kerstin Uvnäs-Moberg
- Department of Animal Environment and Health, Section of Anthrozoology and Applied Ethology, Swedish University of Agricultural Sciences, Skara, Sweden
| | - Ruth C. Newberry
- Faculty of Biosciences, Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway
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López-Arjona M, Botía M, Martínez-Subiela S, Cerón JJ. Oxytocin measurements in saliva: an analytical perspective. BMC Vet Res 2023; 19:96. [PMID: 37507690 PMCID: PMC10386254 DOI: 10.1186/s12917-023-03661-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Oxytocin has traditionally been known for its physiological effects on muscle contraction associated with birth and lactation, but in the last years is widely used as a biomarker of "positive experiences" in psychology and behavior. Different types of samples have been used for oxytocin measurements with saliva samples having the particular advantage of an easy and non-stressful collection. However, the low concentration of oxytocin in saliva can represent a limitation for its use. For this reason, sensitive assays and even a previous sample treatment in some cases are required for saliva oxytocin quantification. In addition, the lack of standardized and generally agreed-upon approach to peripheral oxytocin measurement leads to large discrepancies between different laboratories, that use different sample treatment protocols and different assays. The main objectives of this review are to describe the current status of the use of saliva for oxytocin measurement, provide details of the different sample processing techniques that can be applied and inform about the analytical techniques and assays available in different animal species, and also in humans for comparative purposes. It is expected that this information can contribute to an increase in the knowledge about the measurements of oxytocin in saliva and to its wider use in the future.
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Affiliation(s)
- Marina López-Arjona
- Department of Animal and Food Science, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain.
| | - María Botía
- Interdisciplinary Laboratory of Clinical Analysis, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia (Interlab-UMU), University of Murcia, Campus de Espinardo s/n, Murcia, 30100, Spain
| | - Silvia Martínez-Subiela
- Interdisciplinary Laboratory of Clinical Analysis, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia (Interlab-UMU), University of Murcia, Campus de Espinardo s/n, Murcia, 30100, Spain
| | - José Joaquín Cerón
- Interdisciplinary Laboratory of Clinical Analysis, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia (Interlab-UMU), University of Murcia, Campus de Espinardo s/n, Murcia, 30100, Spain
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Miller SL, Serpell JA, Dalton KR, Waite KB, Morris DO, Redding LE, Dreschel NA, Davis MF. The Importance of Evaluating Positive Welfare Characteristics and Temperament in Working Therapy Dogs. Front Vet Sci 2022; 9:844252. [PMID: 35445102 PMCID: PMC9014261 DOI: 10.3389/fvets.2022.844252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/28/2022] [Indexed: 11/20/2022] Open
Abstract
To date, investigations of the welfare of therapy dogs have focused largely on examining physiological and behavioral measures that could indicate if the animal is experiencing stress or distress. However, this approach does not fully address the definition of welfare which is often described as existing on a continuum from negative (or stressful) to positive. With therapy dogs, it would be worth addressing if they experience positive emotional affect while working since the quality and efficacy of animal-assisted interventions for the human recipient is likely to be influenced by the animal's emotional state during the interaction. The purpose of this review is to articulate how objective measurements of the HPA axis and measurements of behavioral observations and standardized questions can be used to evaluate positive welfare in therapy dogs. A potentially relevant indicator of positive welfare is the peripheral concentration of the neurohormone oxytocin, which has been found to increase in systemic circulation within a variety of species during positive social and affiliative contexts, including during human-dog interaction. Oxytocin is also a negative-feedback regulator of the Hypothalamic-Pituitary-Adrenal (HPA) axis, which culminates with the production of the stress hormone cortisol. Cortisol is widely used as a physiological indicator to assess negative welfare states in animals, including therapy dogs. Observable behavior during interactions with humans that may convey enjoyment could provide indicators of positive welfare in dogs such as engagement in play, or human-directed affiliative behaviors including leaning against, nudging, or licking the patient. However, in assessing positive welfare, it is also critical to consider that all animal behavioral displays and physiological responses are dependent on the dog's individual (and breed) temperament. Temperament directly drives how the animal copes and responds to its current physical and social environment, including during stressful situations such as when therapy dogs interact with unfamiliar humans in novel healthcare settings. Coupled with both positive and negative physiological and behavioral welfare indicators, questionnaire data can provide further context to, and enhance interpretations of, therapy dog welfare assessment results. Overall, to date, no studies have measured all of these factors to assess therapy dog welfare.
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Affiliation(s)
- Sharmaine L Miller
- One Health Laboratory, Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States
| | - James A Serpell
- Department of Clinical Sciences & Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - Kathryn R Dalton
- One Health Laboratory, Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States
| | - Kaitlin B Waite
- One Health Laboratory, Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States
| | - Daniel O Morris
- Department of Clinical Sciences & Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - Laurel E Redding
- Department of Clinical Studies-New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, PA, United States
| | - Nancy A Dreschel
- Department of Animal Science, Pennsylvania State University, University Park, PA, United States
| | - Meghan F Davis
- One Health Laboratory, Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States.,Department of Molecular and Comparative Pathobiology and Division of Infectious Diseases, Johns Hopkins School of Medicine, Baltimore, MD, United States
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Ogi A, Naef V, Santorelli FM, Mariti C, Gazzano A. Oxytocin Receptor Gene Polymorphism in Lactating Dogs. Animals (Basel) 2021; 11:ani11113099. [PMID: 34827831 PMCID: PMC8614403 DOI: 10.3390/ani11113099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 01/29/2023] Open
Abstract
Simple Summary Oxytocin is commonly known for its role in mammalian bonding. Several studies have proved that polymorphisms of the oxytocin receptor gene are related to complex social behaviors in humans, but studies on the possible correlation between canine social behavior and oxytocin are mainly focused on the human–dog bond, and there are no data on the possible correlation between oxytocin receptor gene polymorphism and the maternal behavior of this species. Since mother–litter interactions could have a severe impact in determining later behavior in domestic dogs, the aim of this work was to investigate the possible correlation between salivary oxytocin, maternal care and the one known single-nucleotide polymorphism (rs8679684) located in the untranslated regulatory region of the oxytocin receptor gene in 19 lactating Labrador Retriever dogs. A significant correlation between oxytocin receptor gene polymorphism, peripheral oxytocin and maternal behavior in dogs was found. This implies that a more functional oxytocinergic system would lead to better mothering in dogs. Abstract Genetic variations in the oxytocinergic system, known to regulate social behavior throughout the evolution of mammals, are believed to account for differences in mammalian social behavior. Particularly, polymorphic variants of the oxytocin receptor (OXTR) gene have been associated with behavioral variations in both humans and dogs. In this study, we offered evidence of the correlation between levels of salivary oxytocin (sOXT), maternal behavior and a single-nucleotide gene variant in OXTR (rs8679684) in nineteen lactating Labrador Retriever dogs. Carriers of at least one copy of the minor A allele showed higher levels of sOXT and maternal care in comparison with the homozygous T allele carriers. Considering the relevance of mother care in newborn development, these findings could help us to better understand the possible impact of variants in the OXTR gene in selecting dams.
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Affiliation(s)
- Asahi Ogi
- Department of Veterinary Sciences, University of Pisa, 56124 Pisa, Italy; (C.M.); (A.G.)
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, 56128 Calambrone, Italy; (V.N.); (F.M.S.)
- Correspondence:
| | - Valentina Naef
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, 56128 Calambrone, Italy; (V.N.); (F.M.S.)
| | - Filippo Maria Santorelli
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, 56128 Calambrone, Italy; (V.N.); (F.M.S.)
| | - Chiara Mariti
- Department of Veterinary Sciences, University of Pisa, 56124 Pisa, Italy; (C.M.); (A.G.)
| | - Angelo Gazzano
- Department of Veterinary Sciences, University of Pisa, 56124 Pisa, Italy; (C.M.); (A.G.)
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Akiyama J, Ohta M. Hormonal and Neurological Aspects of Dog Walking for Dog Owners and Pet Dogs. Animals (Basel) 2021; 11:ani11092732. [PMID: 34573698 PMCID: PMC8465204 DOI: 10.3390/ani11092732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/03/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022] Open
Abstract
The hormone oxytocin is involved in various aspects of the relationship between humans and animals. Dog walking is a common activity for dog owners and their dogs. The walk, of course, should be good for the health of the dog as well as its owner. In Experiment I, we assessed whether salivary oxytocin and cortisol in dog owners changed because of walking their dogs. Ten owners walked with their dogs and walked alone. Similar to other previous research, walking with a dog did not significantly change oxytocin and cortisol. Therefore, in Experiment II, we investigated the effect of dog walking on brain noradrenergic and GABAergic neural activity, as indicated by salivary MHPG and GABA, in 14 dog owners. Walking with a dog reduced salivary MHPG compared to walking alone, and MHPG was correlated negatively with GABA. Thus, dog walking activated GABAergic nerves in the brain and suppressed noradrenergic nerves, effectively relieving stress.
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Affiliation(s)
- Junko Akiyama
- Department of Animal Health Technology, Yamazaki University of Animal Health Technology, Tokyo 192-0364, Japan;
| | - Mitsuaki Ohta
- School of Veterinary Medicine, Azabu University, Sagamihara-shi 252-5201, Japan
- Correspondence:
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