Respiration of thermogenic inflorescences of skunk cabbage Symplocarpus renifolius in heliox

Abstract

The respiration rate of the thermogenic inflorescences of Japanese skunk cabbage Symplocarpus renifolius can reach 300 nmol s g , which is sufficient to raise spadix temperature (T ) up to 15 °C above ambient air temperature (T ). Respiration rate is inversely related to T , such that the T achieves a degree of independence from T , an effect known as temperature regulation. Here, we measure oxygen consumption rate (Ṁo ) in air (21% O in mainly N ) and in heliox (21% O in He) to investigate the diffusive conductance of the network of gas-filled spaces and the thermoregulatory response. When T was clamped at 15 °C, the temperature that produces maximal Ṁo in this species, exposure to high diffusivity heliox increased mean Ṁo significantly from 137 ± 17 to 202 ± 43 nmol s g FW, indicating that respiration in air is normally limited by diffusion in the gas phase and some mitochondria are unsaturated. When T was clamped at 15 °C and T was allowed to vary, exposure to heliox reduced T 1 °C and increased Ṁo significantly from 116 ± 10 to 137 ± 19 nmol s g , indicating that enhanced heat loss by conduction and convection can elicit the thermoregulatory response.

A randomized single‐center controlled trial of synchronized intermittent mandatory ventilation with heliox in newborn infants with meconium aspiration syndrome

“…Heliox has been found to have unique advantages in the treatment of respiratory diseases. With the physical characteristic of low density, heliox makes it easier for oxygen to pass through the airway lumen narrowed due to inflammation in infants, which can effectively reduce respiratory resistance, increase the blood oxygen content and improve respiratory system symptoms in infants 11–16 . Another potential benefit of helium is its anti‐inflammatory properties 17 .…”

Perspectives on functions of AOX and UCP in floral thermogenesis

“…植物开花生热最早由 法国博物学家Lamarck在天南星科海芋属(Arum)中发 现. 随后, 研究者相继在木兰科(Magnoliaceae) [2,9,10] 、 泽泻科(Alismataceae) [ 4 ] 、五味子科(Schisandraceae) [11] 、苏铁科(Gycadaceae) [5] 、马兜铃科(Aristolochiaceae) [12] 、棕榈科(Aracaceae) [11] 、环花草科(Cyclanthaceae) [13] 、番荔枝科(Annonaceae) [14,15] 、莲科 (Nelumbonaceae) [16,17] 、菌花科(Hydnoraceae) [18] 以及大 花草科(Rafflesiaceae) [19] 等14科34属中发现开花生热 现象. 这些生热植物科属的发现表明, 开花生热现象在 植物中广泛存在, 也暗示着开花生热可能具有重要的 生物学功能.…”