scholarly journals Environmental temperature and choline requirement in rats. I: Choline deficiency in rats at various temperatures

1966 ◽  
Vol 7 (1) ◽  
pp. 17-21
Author(s):  
J.S. Chahl ◽  
C.C. Kratzing
Author(s):  
F. G. Zaki

Choline-deficiency was induced in Holtzman young rats of both sexes by feeding them a high fat - low protein diet.Preliminary studies of the ultrastructural changes in the myocardium of these animals have been recently reported from this laboratory. Myocardial lesions first appeared in the form of intraventricular mural thrombi, loss of cross striation of muscle fibers and focal necrosis of muscle cells associated with interstitial myocarditis. Prolonged choline-deficiency induced cardiomegaly associated with pericardial edema.During the early phase of this nutritional disorder, heart mitochondria - despite of not showing any swelling similar to that usually encountered in liver mitochondria of the same animal - ware the most ubiquitous site of marked structural abnormalities. Early changes in mitochondria appeared as vacuolation, disorganization, disruption and loss of cristae. Degenerating mitochondria were often seen quite enlarged and their matrix was replaced by whorls of myelin figures resembling lysosomal structures especially where muscle fibers were undergoing necrosis. In some areas, mitochondria appeared to be unusually clumped together where some contained membranelined vacuoles and others enclosed dense bodies and granular inclusions.


2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.


Pathology ◽  
1970 ◽  
Vol 2 (2) ◽  
pp. 125-131 ◽  
Author(s):  
C.C. Kratzing ◽  
G.A. Wetzig ◽  
M. Boland
Keyword(s):  

2010 ◽  
Vol 30 (6) ◽  
pp. 612-614
Author(s):  
Xiao FANG ◽  
Lin LUO ◽  
Lei ZHANG ◽  
Hai-xia QI ◽  
Xiao-dong LIU ◽  
...  

2013 ◽  
Vol 41 (2) ◽  
pp. 218-229
Author(s):  
Fakhry S Salem ◽  
Amany AM Abd Allah ◽  
Sahar S Abd El-Hamied ◽  
Doaa I A Mostafa

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