Differential responses of soil hydrolytic and oxidative enzyme activities to the natural forest conversion

A new model of stretch-induced growth is evaluated in four chicken wing muscles stretched to different extents by a spring-loaded tubular assembly. Muscles grew in length and cross section in proportion to the extent to which they were stretched. Longitudinal growth was essentially completed within 1 wk, while muscles grew in cross section through at least 5 wk of stretch. The muscles were neither denervated nor immobilized, and muscle activity as measured by EMG was not increased. Oxidative enzyme activities increased substantially with stretch in the patagialis (PAT), a twitch muscle, but were relatively unchanged in the slow-tonic anterior latissimus dorsi (ALD). Stretch altered mitochondrial enzyme proportions in the PAT, but had little effect in the ALD. Capillary density was unchanged with stretch in the PAT, but decreased in the ALD. Capillary density was unchanged with stretch in the PAT, but decreased in the ALD. Capillary-to-fiber ratio, however, increased in both muscles. We conclude that muscles grow and adapt enzymatically due to stretch, but that these responses are dissimilar in twitch and tonic muscles.

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Effect of land use on soil enzyme activities at karst area in Nanchuan, Chongqing, Southwest China

Plant Soil and Environment ◽

10.17221/599/2013-pse ◽

2014 ◽

Vol 60 (No. 1) ◽

pp. 15-20 ◽

Cited By ~ 12

Author(s):

Q. Li ◽

Liang JH ◽

He YY ◽

Hu QJ ◽

S. Yu

Keyword(s):

Land Use ◽

Land Use Change ◽

Enzyme Activities ◽

Soil Enzyme ◽

Natural Forest ◽

Karst Area ◽

Soil Enzyme Activities ◽

Soil Urease ◽

Rock Desertification ◽

Clear Change

The study of soil enzyme activities under different land use is of importance for exploration of the soil quality evolution and its evaluation during the revegetation at karst area in Nanchuan, Chongqing, China. Seven kinds of land use were chosen as subject, aiming at revealing the changes in soil enzyme activities through experimental and statistical analysis. The results showed that different land use significantly influenced the enzyme activities. Soil urease, invertase, catalase and amylase behaved the different change. A descending order of urease activity was artificial forest, natural forest, shrubbery, grassland, slope field into terrace, rock desertification and farmland. As to invertase and amylase, they have no clear change orderliness with land use change. Moreover, no significant change was observed in catalase activity and the lower value was found in natural forest. The above results cannot reflect the land use effect on the enzyme activities. According to the soil enzyme index (SEI), it can be seen that the SEI changed with an order of natural forest > artificial forest > grassland > shrubbery > farmland > slope field into terrace > rock desertification, which can objectively and fully evaluate the land use change in soil enzyme.

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Increase in myoglobin content and decrease in oxidative enzyme activities by leg muscle immobilization in man

Acta Physiologica Scandinavica ◽

10.1111/j.1748-1716.1988.tb08358.x ◽

1988 ◽

Vol 132 (4) ◽

pp. 515-517 ◽

Cited By ~ 29

Author(s):

E. Jansson ◽

C. Sylvén ◽

I. Arvidsson ◽

E. Eriksson

Keyword(s):

Enzyme Activities ◽

Oxidative Enzyme ◽

Leg Muscle

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Metabolic variation among alpha-motoneurons innervating different muscle-fiber types. I. Oxidative enzyme activity

Journal of Neurophysiology ◽

10.1152/jn.1984.51.3.529 ◽

1984 ◽

Vol 51 (3) ◽

pp. 529-537 ◽

Cited By ~ 52

Author(s):

D. W. Sickles ◽

T. G. Oblak

Keyword(s):

Optical Density ◽

Muscle Fiber ◽

Enzyme Activities ◽

Tibialis Anterior ◽

Fiber Type ◽

Ventral Horn ◽

Oxidative Enzyme ◽

Muscle Fiber Types ◽

Fiber Types ◽

Fast Twitch

We have examined the oxidative metabolism of rat alpha-motoneurons innervating muscles composed predominantly of one muscle-fiber type. Intramuscular injections of horseradish peroxidase (HRP) into the tensor fasciae latae (TFL) (approximately 94% fast-twitch glycolytic fibers, FG), tibialis anterior (TA) (approximately 66% fast-twitch oxidative-glycolytic, FOG; 32% FG), and soleus (SOL) (approximately 84% slow-twitch oxidative, SO) muscles permitted identification of motoneurons innervating these muscles. gamma-Motoneurons (less than 25-micron average soma diameter) were eliminated from the sampling. The alpha-motoneurons innervating the TFL were considered as FG, those innervating the tibialis anterior as FOG, and those of the soleus as SO. Alternate 5-micron serial cryostat sections were processed for HRP and nicotinamide adenine dinucleotide-diapharase (NADH-D) (oxidative enzyme) activities. Controls were included to assure reliability of reaction product quantitation. Motoneuron pools of each muscle were characterized by their shape and location within the ventral horn. Cells identified on HRP sections as innervating each of the muscles were located on sections processed for NADH-D activity. The optical density of motoneurons in sections processed for NADH-D activity was measured with a Zeiss Zonax MPM 03 microdensitometer. The mean relative NADH-D activities (optical density) of alpha-motoneurons innervating the TFL (FG), TA (FOG), and SOL(SO) muscles were 0.261, 0.305, and 0.447, respectively. Although some overlap in distribution of enzyme activities was observed, statistical analysis indicated significant differences between the NADH-D activities of each type of alpha-motoneuron. This is the first report of any metabolic difference in alpha-motoneurons belonging to different motor-unit types.(ABSTRACT TRUNCATED AT 250 WORDS)

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Loss of soil organic carbon following natural forest conversion to Chinese fir plantation

Forest Ecology and Management ◽

10.1016/j.foreco.2019.117476 ◽

2019 ◽

Vol 449 ◽

pp. 117476 ◽

Cited By ~ 4

Author(s):

Zhijie Yang ◽

Shidong Chen ◽

Xioafei Liu ◽

Decheng Xiong ◽

Chao Xu ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Chinese Fir ◽

Natural Forest ◽

Forest Conversion ◽

Chinese Fir Plantation

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Whole body and muscle energy metabolism in preruminant calves: effects of nutrient synchrony and physical activity

British Journal Of Nutrition ◽

10.1017/s0007114507433098 ◽

2007 ◽

Vol 97 (4) ◽

pp. 667-675 ◽

Cited By ~ 6

Author(s):

Joost J. G. C. van den Borne ◽

Jean-François Hocquette ◽

Martin W. A. Verstegen ◽

Walter J. J. Gerrits

Keyword(s):

Physical Activity ◽

Heat Production ◽

Enzyme Activities ◽

Citrate Synthase ◽

Human Subjects ◽

Fat Content ◽

Oxidative Enzyme ◽

Whole Body ◽

Muscle Energy ◽

Body Heat

The effects of asynchronous availability of amino acids and glucose on muscle composition and enzyme activities in skeletal muscle were studied in preruminant calves. It was hypothesized that decreased oxidative enzyme activities in muscle would explain a decreased whole body heat production with decreasing nutrient synchrony. Preruminant calves were assigned to one of six degrees of nutrient synchrony, step-wise separating the intake of protein and lactose over the two daily meals. Calves at the most synchronous treatment received two identical meals daily. At the most asynchronous treatment, 85 % of the daily protein and 20 % of the daily lactose supply were fed in one meal and the remainder in the other meal. Daily intakes of all dietary ingredients were identical for all treatments. Oxidative enzyme activities and fat content increased with decreasing nutrient synchrony inM. Rectus Abdominis(RA), but not inM. Semitendinosus. Cytochrome-c-oxidase activity was positively correlated with fat content in RA (r0·49;P < 0·01). Oxidative enzyme activities in both muscles were not correlated with average daily heat production, but citrate synthase activity in RA was positively correlated (P < 0·01) with the circadian amplitude (r0·53) and maximum (r0·61) of heat production associated with physical activity. In conclusion, this study indicates that muscle energy stores are regulated by nutrient synchrony. The lack of correlation between muscle oxidative enzyme activities and average daily heat production was in contrast with findings in human subjects. Therefore, oxidative enzyme activity in muscle should not be used as an indicator for whole body heat production in growing calves.

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