Alterations in TNF-α and its receptors expression in cows undergoing heat stress

Pereira

Wang

et al. 2021

Self Cite

Infrared thermography (IRT) is a non-ionizing, non-invasive technique that permits evaluating the comfort levels of animals, a topic of concern due to the growing interest in determining the state of health and welfare of production animals. The operating principle of IRT is detecting the heat irradiated in anatomical regions characterized by a high density of near-surface blood vessels that can regulate temperature gain or loss from/to the environment by modifying blood flow. This is essential for understanding the various vascular thermoregulation mechanisms of different species, such as rodents and ruminants’ tails. The usefulness of ocular, nasal, and vulvar thermal windows in the orbital (regio orbitalis), nasal (regio nasalis), and urogenital (regio urogenitalis) regions, respectively, has been demonstrated in cattle. However, recent evidence for the river buffalo has detected discrepancies in the data gathered from distinct thermal regions in these large ruminants, suggesting a limited sensitivity and specificity when used with this species due to various factors: the presence of hair, ambient temperature, and anatomical features, such as skin thickness and variations in blood supplies to different regions. In this review, a literature search was conducted in Scopus, Web of Science, ScienceDirect, and PubMed, using keyword combinations that included “infrared thermography”, “water buffalo”, “river buffalo” “thermoregulation”, “microvascular changes”, “lacrimal caruncle”, “udder”, “mastitis”, and “nostril”. We discuss recent findings on four thermal windows—the orbital and nasal regions, mammary gland in the udder region (regio uberis), and vulvar in the urogenital region (regio urogenitalis)—to elucidate the factors that modulate and intervene in validating thermal windows and interpreting the information they provide, as it relates to the clinical usefulness of IRT for cattle (Bos) and the river buffalo (Bubalus bubalis).

Section: Environmental Influence On the Physiological Responses Of Thermoregulationmentioning

confidence: 99%

Section: Perspectives and Areas Of Opportunitymentioning

confidence: 99%

“…The neuroendocrine response to heat stress negatively affects behavior and productive and reproductive efficiency, with consequences for milk and meat production, growth, and fertility [ 104 ]. Moreover, heat stress has been shown to affect the gene expression of cytokines and their receptors, consequently affecting immune functions [ 118 , 119 ]. Hence, it is essential to acknowledge the influence of ambient temperature on the thermoregulation of the river buffalo, but also factors of this kind when measuring thermal and microvascular changes in animals.…”

Section: Environmental Influence On the Physiological Responses Of Thermoregulationmentioning

confidence: 99%

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Clinical Applications and Factors Involved in Validating Thermal Windows Used in Infrared Thermography in Cattle and River Buffalo to Assess Health and Productivity

Pereira

Wang

et al. 2021

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“…Faced with febrile processes, both mammals and birds present behaviors such as loss of appetite, social isolation, and, in more severe conditions, reduced activity, mainly due to the effect of cytokines [ 7 , 99 ]. The development of these behaviors that facilitate the detection of sick animals allows them to save energy in the short-term, reduce the transmission of infection, and ensure the efficient functioning of NK cells and interleukin 2 to respond to the antigen challenge [ 7 , 100 , 101 , 102 , 103 ].…”

Section: How Does An Animal With a Fever Thermoregulate? (Neurophysiological Responses To Temperature Control)mentioning

confidence: 99%

Pathophysiology of Fever and Application of Infrared Thermography (IRT) in the Detection of Sick Domestic Animals: Recent Advances

Wang

Titto

et al. 2021

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Body-temperature elevations are multifactorial in origin and classified as hyperthermia as a rise in temperature due to alterations in the thermoregulation mechanism; the body loses the ability to control or regulate body temperature. In contrast, fever is a controlled state, since the body adjusts its stable temperature range to increase body temperature without losing the thermoregulation capacity. Fever refers to an acute phase response that confers a survival benefit on the body, raising core body temperature during infection or systemic inflammation processes to reduce the survival and proliferation of infectious pathogens by altering temperature, restriction of essential nutrients, and the activation of an immune reaction. However, once the infection resolves, the febrile response must be tightly regulated to avoid excessive tissue damage. During fever, neurological, endocrine, immunological, and metabolic changes occur that cause an increase in the stable temperature range, which allows the core body temperature to be considerably increased to stop the invasion of the offending agent and restrict the damage to the organism. There are different metabolic mechanisms of thermoregulation in the febrile response at the central and peripheral levels and cellular events. In response to cold or heat, the brain triggers thermoregulatory responses to coping with changes in body temperature, including autonomic effectors, such as thermogenesis, vasodilation, sweating, and behavioral mechanisms, that trigger flexible, goal-oriented actions, such as seeking heat or cold, nest building, and postural extension. Infrared thermography (IRT) has proven to be a reliable method for the early detection of pathologies affecting animal health and welfare that represent economic losses for farmers. However, the standardization of protocols for IRT use is still needed. Together with the complete understanding of the physiological and behavioral responses involved in the febrile process, it is possible to have timely solutions to serious problem situations. For this reason, the present review aims to analyze the new findings in pathophysiological mechanisms of the febrile process, the heat-loss mechanisms in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of IRT.

“…Interestingly, although their structure has been studied in great detail, we still do not fully understand the mechanism by which TRP opens and closes its gates from the moment a thermal stimulus is perceived. Against this backdrop, the goals of this review are to analyze and contrast recent scientific findings on the morphology, physiology, and neurotransmission mechanisms of TRP, and their function in thermoregulation in non-human animals, as well as enhance our understanding of their functionality and fundamental role in maintaining the body temperature of animals and those susceptible to thermal stress—as can occur during transport [ 27 , 28 , 29 ].…”

Section: Introductionmentioning

confidence: 99%

Transient Receptor Potential (TRP) and Thermoregulation in Animals: Structural Biology and Neurophysiological Aspects

Lezama-García

Pereira

et al. 2022

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This review presents and analyzes recent scientific findings on the structure, physiology, and neurotransmission mechanisms of transient receptor potential (TRP) and their function in the thermoregulation of mammals. The aim is to better understand the functionality of these receptors and their role in maintaining the temperature of animals, or those susceptible to thermal stress. The majority of peripheral receptors are TRP cation channels formed from transmembrane proteins that function as transductors through changes in the membrane potential. TRP are classified into seven families and two groups. The data gathered for this review include controversial aspects because we do not fully know the mechanisms that operate the opening and closing of the TRP gates. Deductions, however, suggest the intervention of mechanisms related to G protein-coupled receptors, dephosphorylation, and ligands. Several questions emerge from the review as well. For example, the future uses of these data for controlling thermoregulatory disorders and the invitation to researchers to conduct more extensive studies to broaden our understanding of these mechanisms and achieve substantial advances in controlling fever, hyperthermia, and hypothermia.