昆虫は酸素の毒性を避けるために断続的に呼吸します

Stefan K Hetz¹, Timothy J Bradley

¹Department of Animal Physiology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany.

Nature

|February 4, 2005

まとめ

昆虫の螺旋は循環的に開き,二酸化炭素 (CO2) を放出し,酸素 (O2) の毒性を防ぐ. この絶え間ないガス交換は,代謝需要とO2の有害な効果をバランスとします.

科学分野:

昆虫の生理学昆虫の生理学
呼吸器ガスの交換
環境への適応環境への適応

背景:

陸上の昆虫は,気管系をスパイラクルでガス交換に利用しています.
多くの昆虫は,長期にわたるスパイラキュラー閉塞で不連続なガス交換を示します.
このパターンの既存の仮説には,水資源の保存と低酸素/高気圧環境への適応が含まれています.

研究の目的:

昆虫における不連続のガス交換に関する新しい説明を提案する.
昆虫の呼吸を調節する酸素毒性の役割を調査する.
CO2除去とO2曝露のバランスを探すために.

主な方法:

昆虫の気管系内のガス拡散の理論モデル化.
O2とCO2の生理学的部分圧力の分析.
酸化ストレスメカニズムに基づいた仮説の構想.

主要な成果:

昆虫の呼吸器系からのCO2の拡散は,生理学的CO2レベルでのO2の侵入よりも遅い.
スピラクルが閉ざされたときに,イントラケアルCO2が蓄積される.
CO2の放出のためにスパイラクルの開口が必要であり,一時的に高いO2被曝につながります.

結論:

絶え間ないガス交換は,内二酸化炭素の蓄積を管理するための戦略です.
サイクリックなスパイラル開口は,CO2除去とO2毒性の軽減のバランスをとる結果です.
このパターンは,代謝要件と酸化ダメージ予防の間の進化的妥協を反映しています.

さらに関連する動画

07:10

At-Risk Butterfly Captive Propagation Programs to Enhance Life History Knowledge and Effective Ex Situ Conservation Techniques

Published on: February 11, 2020

06:00

Electroantennography-based Bio-hybrid Odor-detecting Drone using Silkmoth Antennae for Odor Source Localization

Published on: August 27, 2021

関連する概念動画

01:47

Osmoregulation in Insects

Malpighian tubules are specialized structures found in the digestive systems of many arthropods, including most insects, that handle excretion and osmoregulation. The tubules are typically arranged in pairs and have a convoluted structure that increases their surface area.

02:39

Predator-Prey Interactions

Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.Although predation is commonly associated with carnivory, for...

01:30

Alterations in Respiration II

There are numerous types of normal and abnormal respiration. Based on ventilatory movements, breathing patterns are classified as regular, deep, or shallow. Examples include Biot's breathing, Cheyne-Stokes respiration, Kussmaul's breathing, hyperventilation, and hypoventilation. Each pattern is clinically significant and aids in evaluating patients.
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes include...

01:24

External and Internal Respiration

External respiration occurs in the lungs, and it is the first step in the journey of oxygen inside the body. When we inhale, oxygen enters our lungs and diffuses across the thin alveolar membrane. The alveoli are tiny, air-filled sacs that provide a vast surface area for gas exchange. Oxygen in the alveoli has a higher partial pressure (105 mmHg) than in the adjacent pulmonary capillaries (40 mmHg), establishing a pressure gradient. As a result, oxygen molecules move from the alveoli into the...

01:17

Other Factors Affecting Respiration Centers

Breathing is primarily an involuntary activity regulated by the brainstem respiratory centers. However, it can also be consciously controlled, allowing us to hold our breath or take deeper breaths when needed. This voluntary control is facilitated by the cerebral motor cortex, which bypasses the medullary centers to stimulate the respiratory muscles directly.
However, the ability to hold one's breath voluntarily is not limitless. When the CO2 concentration in the blood reaches a critical level,...

01:30

Acute Respiratory Failure-III

Hypercapnic respiratory failure, also known as Type 2 or ventilatory respiratory failure, is a severe condition characterized by the body's inability to effectively remove carbon dioxide (CO2) from the bloodstream. It leads to an arterial CO2 pressure (PaCO2) exceeding 45 mmHg and a blood pH above 7.35. This situation indicates that the body's ventilatory demand, or the ventilation needed to maintain normal PaCO2 levels, surpasses its supply or the maximum gas flow achievable without causing...

関連する実験動画