Temperature- and body mass-related variation in cyclic gas exchange characteristics and metabolic rate of seven weevil species: Broader implications

2005 ◽  
Vol 51 (7) ◽  
pp. 789-801 ◽  
Author(s):  
C.J. Klok ◽  
S.L. Chown
Keyword(s):  
Gas Exchange ◽  
Metabolic Rate ◽  
Body Mass ◽  
Related Variation ◽  
Weevil Species ◽  
Gas Exchange Characteristics

scholarly journals Body mass-specific Na+-K+-ATPase activity in the medullary thick ascending limb: implications for species-dependent urine concentrating mechanisms

2018 ◽  
Vol 314 (4) ◽  
pp. R563-R573 ◽  
Author(s):  
Mun Aw ◽  
Tamara M. Armstrong ◽  
C. Michele Nawata ◽  
Sarah N. Bodine ◽  
Jeeeun J. Oh ◽  
...  
Keyword(s):  
Protein Expression ◽  
Atpase Activity ◽  
Metabolic Rate ◽  
Body Mass ◽  
Whole Body ◽  
Osmotic Gradient ◽  
Thick Ascending Limb ◽  
Rat Strains ◽  
Kangaroo Rat ◽  
Gene And Protein Expression

In general, the mammalian whole body mass-specific metabolic rate correlates positively with maximal urine concentration (Umax) irrespective of whether or not the species have adapted to arid or mesic habitat. Accordingly, we hypothesized that the thick ascending limb (TAL) of a rodent with markedly higher whole body mass-specific metabolism than rat exhibits a substantially higher TAL metabolic rate as estimated by Na+-K+-ATPase activity and Na+-K+-ATPase α1-gene and protein expression. The kangaroo rat inner stripe of the outer medulla exhibits significantly higher mean Na+-K+-ATPase activity (~70%) compared with two rat strains (Sprague-Dawley and Munich-Wistar), extending prior studies showing rat activity exceeds rabbit. Furthermore, higher expression of Na+-K+-ATPase α1-protein (~4- to 6-fold) and mRNA (~13-fold) and higher TAL mitochondrial volume density (~20%) occur in the kangaroo rat compared with both rat strains. Rat TAL Na+-K+-ATPase α1-protein expression is relatively unaffected by body hydration status or, shown previously, by dietary Na+, arguing against confounding effects from two unavoidably dissimilar diets: grain-based diet without water (kangaroo rat) or grain-based diet with water (rat). We conclude that higher TAL Na+-K+-ATPase activity contributes to relationships between whole body mass-specific metabolic rate and high Umax. More vigorous TAL Na+-K+-ATPase activity in kangaroo rat than rat may contribute to its steeper Na+ and urea axial concentration gradients, adding support to a revised model of the urine concentrating mechanism, which hypothesizes a leading role for vigorous active transport of NaCl, rather than countercurrent multiplication, in generating the outer medullary axial osmotic gradient.

Gas exchange characteristics and dry matter accumulation of soybean treated with Nod factors

2007 ◽  
Vol 164 (10) ◽  
pp. 1391-1393 ◽  
Author(s):  
Juan Jose Almaraz ◽  
Xiaomin Zhou ◽  
Alfred Souleimanov ◽  
Donald Smith
Keyword(s):  
Gas Exchange ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Nod Factors ◽  
Gas Exchange Characteristics

Fluctuations in O2 stores and gas exchange with passive changes in posture

1975 ◽  
Vol 39 (1) ◽  
pp. 47-53 ◽  
Author(s):  
J. A. Loeppky ◽  
U. C. Luft
Keyword(s):  
Cardiac Output ◽  
Gas Exchange ◽  
Metabolic Rate ◽  
Blood Volume ◽  
Mass Spectrometer ◽  
Rapid Loss ◽  
Pulmonary Capillary ◽  
O2 Transfer

To clarify the role of O2 stores in the fluctuations in VO2 observed with changing posture, O2 intake (Veo2) and pulmonary capillary O2 transfer (Vpco2) were calculated breath by breath with a box-balloon sprometer and mass spectrometer. Changes in O2 stores of the lungs (O2L) and blood (O2b) were computed assuming metabolic rate (Vco2) constant (O2L = Veo2 - Vpco2; O2b = Vpco2 - Vco2). Measurements were made before, during, and after passive tilt to 60 degrees and on return to recumbency after 10 min erect. From supine to upright O2L increased rapidly and O2b dropped slowly, creating a net deficit in Veo2 of 130 ml in 10 min. Return to supine caused rapid loss in O2L and gain in O2b with a net Veo2 excess of 117 ml. Shifts in O2b were 2.5 times greater but opposite to shifts in O2L. Changes in O2b result from shifts in blood volume and flow more than from changes in cardiac output. Refilling of O2b, matching loss while upright, caused transient hypoxia with significant hyperpnea.

scholarly journals Role of Ferrous Sulfate (FeSO4) in Resistance to Cadmium Stress in Two Rice (Oryza sativa L.) Genotypes

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1693
Author(s):  
Javaria Afzal ◽  
Muhammad Hamzah Saleem ◽  
Fatima Batool ◽  
Ali Mohamed Elyamine ◽  
Muhammad Shoaib Rana ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gas Exchange ◽  
Plant Growth ◽  
Photosynthetic Pigments ◽  
Ferrous Sulfate ◽  
Oryza Sativa L ◽  
Enzymatic Antioxidants ◽  
Cd Stress ◽  
Ultra Structure ◽  
Gas Exchange Characteristics

The impact of heavy metal, i.e., cadmium (Cd), on the growth, photosynthetic pigments, gas exchange characteristics, oxidative stress biomarkers, and antioxidants machinery (enzymatic and non-enzymatic antioxidants), ions uptake, organic acids exudation, and ultra-structure of membranous bounded organelles of two rice (Oryza sativa L.) genotypes (Shan 63 and Lu 9803) were investigated with and without the exogenous application of ferrous sulfate (FeSO4). Two O. sativa genotypes were grown under different levels of CdCl2 [0 (no Cd), 50 and 100 µM] and then treated with exogenously supplemented ferrous sulfate (FeSO4) [0 (no Fe), 50 and 100 µM] for 21 days. The results revealed that Cd stress significantly (p < 0.05) affected plant growth and biomass, photosynthetic pigments, gas exchange characteristics, affected antioxidant machinery, sugar contents, and ions uptake/accumulation, and destroy the ultra-structure of many membranous bounded organelles. The findings also showed that Cd toxicity induces oxidative stress biomarkers, i.e., malondialdehyde (MDA) contents, hydrogen peroxide (H2O2) initiation, and electrolyte leakage (%), which was also manifested by increasing the enzymatic antioxidants, i.e., superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) and non-enzymatic antioxidant compounds (phenolics, flavonoids, ascorbic acid, and anthocyanin) and organic acids exudation pattern in both O. sativa genotypes. At the same time, the results also elucidated that the O. sativa genotypes Lu 9803 are more tolerant to Cd stress than Shan 63. Although, results also illustrated that the exogenous application of ferrous sulfate (FeSO4) also decreased Cd toxicity in both O. sativa genotypes by increasing antioxidant capacity and thus improved the plant growth and biomass, photosynthetic pigments, gas exchange characteristics, and decrease oxidative stress in the roots and shoots of O. sativa genotypes. Here, we conclude that the exogenous supplementation of FeSO4 under short-term exposure of Cd stress significantly improved plant growth and biomass, photosynthetic pigments, gas exchange characteristics, regulate antioxidant defense system, and essential nutrients uptake and maintained the ultra-structure of membranous bounded organelles in O. sativa genotypes.

scholarly journals LEAF GAS EXCHANGE CHARACTERISTICS OF FOUR PAPAYA GENOTYPES DURING DIFFERENT STAGES OF DEVELOPMENT

2001 ◽  
Vol 23 (3) ◽  
pp. 522-525 ◽  
Author(s):  
ELIEMAR CAMPOSTRINI ◽  
OSVALDO KIYOSHI YAMANISHI ◽  
CARLOS A. MARTINEZ
Keyword(s):  
Gas Exchange ◽  
Carica Papaya ◽  
Leaf Gas Exchange ◽  
Carbon Dioxide Concentration ◽  
Field Capacity ◽  
Experimental Period ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Loam Soil ◽  
Gas Exchange Characteristics

In this research, was used four papaya (Carica papaya L.) genotypes: three from the 'Solo ( Sunrise Solo TJ, Sunrise Solo 72/12 and Baixinho de Santa Amália) group and one from the 'Formosa' group (Know-You 01). They were grown in plastic pots containing a sandy-clay-loam soil subjected to pH correction and fertilization, under greenhouse conditions. Throughout the experimental period plants were subjected to periodic irrigation to maintain the soil humitidy around field capacity. The experiment was conducted 73 days after sowing. In all genotypes, leaf gas exchange characteristics were determined. The net photosynthetic rate (A, mumol m-2 s-1 ), stomatal conductance (g s mol m-2 s-1), leaf temperature (T I, 0C) and intercellular carbon dioxide concentration (ci, muL L-1) on the 4th, 5th, 6th, 7th, 8th and 9th leaves from the plant apex were determined. No significant differences were observed for A, g s, c i, or Tl either among the leaves sampled from any of the genotypes. A was positively correlated with g s and in the other hand T I and g s were negatively correlated. The results suggest that, for 73 DAP, all the sampled papaya leaves functioned as sources of organs.

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