Advancing Our Understanding of How Cardiovascular Control, Function and Plasticity Influence Fish Performance and Ecophysiology

增进我们对心血管控制、功能和可塑性如何影响鱼类性能和生态生理学的理解

• 批准号: RGPIN-2022-03790
• 负责人: Gamperl, Anthony
• 金额: $ 5.68万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761574
• 关键词: Advancing; Our; Understanding; How; Cardiovascular

The cardiorespiratory system (gills, heart, blood, blood vessels) is critical to the survival of fish as it ensures adequate oxygen and nutrient delivery to the tissues. In addition, it is important that these nutrients and oxygen are used efficiently by mitochondria (the 'powerhouses' of cells) so that enough energy is produced to meet the fish's demands (even under stressful conditions). My research program examines how metabolic rate, heart function, blood vessel physiology, mitochondrial function and stress physiology differ between fish species/populations, and how this allows them to survive under challenging conditions; including climate change. While we have made tremendous progress in understanding fish cardiorespiratory function and its relationship to performance / survival over the past decade, this research has left many important questions unanswered. My trainees (6 graduate and 5 undergraduate students, and 1 post-doc) and I will address a number of these in this grant. Three fundamental questions in fish cardiovascular physiology are: 1) what factors determine between individual, and between species, differences in maximum heart rate and function?; 2) what limits heart function at high temperatures?; and 3) what mechanisms constrain the capacity of fishes to increase stroke volume (how much blood is pumped per heart beat) as temperatures change. We will address all of these questions. Recent studies in my lab have also shown that fish exposed to low oxygen levels (hypoxia) are unable to increase their heart rate when exposed to high temperatures, and that this makes them susceptible to heat waves. Thus, we will perform several experiments to examine the physiological and control mechanisms leading to this limitation. Further, we will investigate whether the capacity of the fish to extract oxygen from their blood, and mitochondrial function, are key determinants of how tolerant they are of severe hypoxic (low oxygen) conditions and high temperatures, respectively. Finally, we will conduct a number of studies on very small coronary vessels (i.e., microvessels, the ones that are most important in controlling blood flow to tissues), and similar vessels in the gonads (ovaries and testes) of fish. The former studies are a continuation of previous work, and are critical to perform as coronary blood flow is key to cardiac performance under stressful conditions. The studies on gonad vessels will be performed because blood flow to these organs is important for egg and sperm development / quality (i.e., producing the next generation), respectively, and data on coronary vessels may not reflect how temperature or various hormones affect vessel dilation/constriction, and thus blood flow, in other tissues. Collectively, this research will greatly enhance our knowledge of how the fish cardiorespiratory system responds to both acute and chronic stressors, and will have important implications for fish management and conservation.

心肺系统（g，心脏，血液，血管）对于鱼的存活至关重要，因为它可以确保足够的氧气和养分向组织。此外，重要的是，这些营养素和氧气由线粒体（细胞的“电荷”）有效地使用，以便产生足够的能量来满足鱼的需求（即使在压力很大的条件下）。我的研究计划研究了鱼类/种群之间的代谢率，心脏功能，血管生理学，线粒体功能和压力生理的不同，以及这如何允许它们在具有挑战性的条件下生存；包括气候变化。尽管我们在过去十年中了解鱼心肺功能及其与绩效 /生存的关系方面取得了巨大进展，但这项研究使许多重要的问题尚未得到解决。我的学员（6名毕业生和5名本科生，以及大约1名），我将在这笔赠款中处理其中的许多。 鱼类心血管生理学的三个基本问题是：1）个体和物种之间的哪些因素，最大心率和功能的差异？ 2）什么限制了高温下心脏功能？ 3）随着温度的变化，哪些机制限制了鱼类增加中风量的能力（每次心跳加血量多少）。我们将解决所有这些问题。 在我的实验室中，最近的研究还表明，暴露于低氧水平（缺氧）的鱼在暴露于高温时无法提高心率，这使其容易受到热波。因此，我们将执行几个实验，以检查导致这种限制的生理和控制机制。此外，我们将研究鱼从血液中提取氧气的能力以及线粒体功能是否是它们的耐受性的关键决定因素，它们分别具有严重的低氧（低氧）条件和高温。最后，我们将对非常小的冠状动脉血管（即微量花序，在控制流向组织的血流中最重要的血液）以及鱼类中类似血管（卵巢和睾丸）中的类似血管进行多项研究。以前的研究是先前工作的延续，并且对于冠状动脉血流而言至关重要，这是在压力条件下的心脏表现的关键。将对性腺血管进行研究，因为这些器官的血流分别对于卵和精子发育 /质量（即产生下一代）很重要，冠状血管的数据可能不会反映温度或各种激素如何影响血管扩张 /约束，从而在其他组织中如何影响血管的膨胀 /约束。 总的来说，这项研究将大大增强我们对鱼心肺系统如何对急性和慢性压力源做出反应的了解，并将对鱼类管理和保护具有重要意义。