Effect of dietary restriction on sperm characteristic and oxidative status on testicular tissue in young rats exposed to long-term heat stress

Andrologia ◽  
2014 ◽  
Vol 47 (9) ◽  
pp. 1055-1061 ◽  
Author(s):  
N. Aydilek ◽  
O. Varisli ◽  
A. Kocyigit ◽  
A. Taskin ◽  
M. S. Kaya
2015 ◽  
Vol 27 (1) ◽  
pp. 225
Author(s):  
N. Aydilek ◽  
O. Varisli ◽  
M. S. Kaya ◽  
A. Kocyigit ◽  
A. Taskin

The objective was to evaluate effects of dietary restriction on oxidative status and sperm parameters in rats exposed to long-term heat stress. Forty healthy Sprague-Dawley rats (2.5 months old) were equally allocated into 4 groups (with respect to diet and temperature): room temperature (22°C)-ad libitum; room temperature-dietary restriction (40%); high temperature (38°C)-ad libitum; and high temperature-dietary restriction. At the end of the 9th week, some oxidants (lipid hydroperoxide, total oxidant status, oxidative stress index) and some antioxidants (total antioxidant status, sulfhydryl groups, ceruloplasmin, paraoxonase and arylesterase activities) were measured in testicular tissues. In addition, concentration, motility, volume, abnormal sperm count, acrosome and membrane integrity of epididymal sperm were also evaluated. All data were analysed by 2-way ANOVA (P < 0.05). High temperature did not significantly affect most oxidative and antioxidative parameters (except for sulfhydryl groups and ceruloplasmin), yet it impaired all sperm values. Neither sperm values nor oxidative status, with the exception of sulfhydryl groups, ceruloplasmin and arylesterase in the testis tissue, were significantly affected by dietary restriction. We concluded that long-term heat stress did not significantly affect testicular oxidative status in young rats, although sperm were sensitive to heat stress. Furthermore, dietary restriction failed to improve sperm quality and oxidative status, except some individual antioxidant parameters in young rats exposed to long-term heat stress.


2016 ◽  
Vol 32 (3) ◽  
pp. 161-161
Author(s):  
Faruk Bozkaya ◽  
Mehmet Osman Atlı ◽  
Aydin Guzeloglu ◽  
Seyit Ali Kayis ◽  
Mehmet Salih Kaya ◽  
...  

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.


2021 ◽  
pp. 102876
Author(s):  
Maria Emilia Fernandez ◽  
Maria Carla Labaque ◽  
Gabriel Orso ◽  
Raúl Hector Marin ◽  
Jackelyn Melissa Kembro

Author(s):  
Kazuho Isono ◽  
Ryo Tsukimoto ◽  
Satoshi Iuchi ◽  
Akihisa Shinozawa ◽  
Izumi Yotsui ◽  
...  

Abstract Plants are often exposed not only to short-term (S-) heat stress but also to diurnal long-term (L-) heat stress over several consecutive days. To reveal the mechanisms underlying L-heat stress tolerance, we here used a forward genetic screening for sensitive to long-term heat (sloh) mutants and isolated sloh4. The mutant was hypersensitive to L- but not S-heat stress. The causal gene of sloh4 was identical to MIP3 encoding a member of the MAIGO2 (MAG2) tethering complex, which is composed of the MAG2, MIP1, MIP2, and MIP3 subunits and is localized at the endoplasmic reticulum (ER) membrane. Although sloh4/mip3 was hypersensitive to L-heat stress, the sensitivity of the mag2-3 and mip1–1 mutants was similar to that of the wild type. Under L-heat stress, the ER stress and the following unfolded protein response (UPR) were more pronounced in sloh4 than in the wild type. Transcript levels of bZIP60-regulated UPR genes were strongly increased in sloh4 under L-heat stress. Two processes known to be mediated by INOSITOL REQUIRING ENZYME1 (IRE1)—accumulation of the spliced bZIP60 transcript and a decrease in the transcript levels of PR4 and PRX34, encoding secretory proteins—were observed in sloh4 in response to L-heat stress. These findings suggest that misfolded proteins generated in sloh4 under L-heat stress may be recognized by IRE1 but not bZIP28, resulting in initiation of the UPR via activated bZIP60. Therefore, it would be possible that only MIP3 in MAG2 complex has an additional function in L-heat tolerance, which is not related to the ER–Golgi vesicle tethering.


Zygote ◽  
2019 ◽  
Vol 27 (6) ◽  
pp. 432-435
Author(s):  
Thais Rose dos Santos Hamilton ◽  
Gabriela Esteves Duarte ◽  
José Antonio Visintin ◽  
Mayra Elena Ortiz D’Ávila Assumpção

SummaryLong-term heat stress (HS) induced by testicular insulation generates oxidative stress (OS) on the testicular environment; consequently activating antioxidant enzymes such as superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GPx). The aim of this work was to immunolocalize antioxidant enzymes present in different cells within the seminiferous tubule when rams were submitted to HS. Rams were divided into control (n = 6) and treated group (n = 6), comprising rams subjected to testicular insulation for 240 h. After the testicular insulation period, rams were subjected to orchiectomy. Testicular fragments were submitted to immunohistochemistry for staining against SOD, GR and GPx enzymes. We observed immunolocalization of GPx in more cell types of the testis after HS and when compared with other enzymes. In conclusion, GPx is the main antioxidant enzyme identified in testicular cells in an attempt to maintain oxidative balance when HS occurs.


2013 ◽  
Vol 33 (3) ◽  
pp. 216-222 ◽  
Author(s):  
Muzaffer Tas ◽  
Suleyman Dasdag ◽  
Mehmet Zulkuf Akdag ◽  
Umut Cirit ◽  
Korkut Yegin ◽  
...  

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