Effect of eccentric training on mitochondrial function and oxidative stress in the skeletal muscle of rats

The objective of the present study was to investigate the effects of eccentric training on the activity of mitochondrial respiratory chain enzymes, oxidative stress, muscle damage, and inflammation of skeletal muscle. Eighteen male mice (CF1) weighing 30-35 g were randomly divided into 3 groups (N = 6): untrained, trained eccentric running (16°; TER), and trained running (0°) (TR), and were submitted to an 8-week training program. TER increased muscle oxidative capacity (succinate dehydrogenase and complexes I and II) in a manner similar to TR, and TER did not decrease oxidative damage (xylenol and creatine phosphate) but increased antioxidant enzyme activity (superoxide dismutase and catalase) similar to TR. Muscle damage (creatine kinase) and inflammation (myeloperoxidase) were not reduced by TER. In conclusion, we suggest that TER improves mitochondrial function but does not reduce oxidative stress, muscle damage, or inflammation induced by eccentric contractions.

Histological and scanning electron microscopic study of the effect of cigarette smoke on the heart of male albino rats

Environmental tobacco smoke has been shown to cause heart diseases among non-smokers. Twenty one adult male albino rats were used to investigate the effect of cigarette smoke on the heart and to evaluate the possibility of recovery. Rats were divided into 3 equal groups. Rats of group I were considered as control Rats of group II were exposed to cigarette smoke for 4 weeks, while those of group III were exposed to cigarette smoke for 4 weeks then the exposure was stopped for another 4 weeks. Exposure to cigarette smoke resulted in affection of the coronaries. Some cardiac muscle fibers showed vacuolated cytoplasm, while other showed deeply stained acidophilic cytoplasm and psychotic nuclei. Scanning electron microscopic examination showed that some cardiac muscle fibers appeared necrotic with loss of their normal architecture. There was a decrease in succinic dehydrogenase enzyme activity and in the antiapoptotic Bcl-x [L]protein expression. Stopping the exposure for 4 weeks showed that few cardiac muscle fibers were still affected. Areas of fibrosis were seen between the cardiac muscle fibers in Mallroy stained sections and in the scanning electron microscopic study. There was an increase in scenic dehydrogenase enzyme activity and in the Bcl-x[L] protein expression in the cardiac muscle fibers in group III- that was left for 4 weeks for recovery after 4 weeks of exposure to cigarette smoke- in comparison to those of group II, but was still less than those of the control It is concluded that cigarette smoke affected the cardiac muscle and some of its effects could not be reversible

Cigarette smoking and spermatozoa II. effect of ascorbic acid supplementation on spermatozoa of cigarette smokers [histochemical study]

The thirty heavy smoking men investigated in the first portion of our work were randomly divided into two subgroups [each contained 15 men]. Each participant from the first subgroup of smokers took one 1000-mg tablet of ascorbic acid [AA] daily for 4 weeks. For the same period, the members of the second subgroup took placebo tablets, serving as negative controls. Also, another fifteen of the non-smokers participated as a separate group and each took one 1000-mg tablet of AA daily for 4 weeks, serving as positive controls. The histochemical differences between sperms of cigarette smokers and non-smokers in the first portion of this work were surveyed. Serum and seminal plasma ascorbic acid levels were measured. Statistically significant increases in the histochemical reactions and ascorbic acid levels in the treated subgroup were observed weekly. After the 4 weeks of supplementation, no significant difference was detected between the treated subgroup and non-smokers. However, no significant changes were observed in the non-smokers or the placebo subgroup indicating that increased ascorbic acid bioavailability was associated with the pronounced improvement in sperm activity. These useful effects of AA supplementation may be due to its reductive properties nullifying the possible iniurious effects of the reactive oxidants of nicotine or nicotine melabolites

Histopathological, ultra-structural and histochemical studies on the liver of schistosoma mansoni infected mice under the effect of triclabendazole

The present work investigated the effect of the fasciolicidal drug triclabendazole [TCBZ] on the liver of S. mansoni infected mice. The drug was given to normal as well as to S. mansoni infected mice. The work included histopathological, ultra-structural and histochemical studies. In the normal liver TCBZ induced the formation of scanty foci of inflammatory infiltrate. No changes were observed at the subcellular level or in the hepatocytes enzymes succinic dehydrogenase [SDH] and acid phosphatase [ACP]. The liver of S. mansoni infected mice revealed the classical histopathological picture of schistosomiasis. After TCBZ treatment, the granulomata involuted revealing fibrous transformation. The ultrastructural of hepatocytes of S. mansoni infected mice revealed distortion of the mitochondria, increased number of lysosomes and obliteration of Disse space. These electron microscopic [EM] changes were less obvious after TCBZ therapy denoting improvement of the hepatocellular insufficiency. Histochemically, an increase in ACP and a decrease in SDH activity were observed in S. mansoni infected liver. The activity of these enzymes returned to normal after treatment with TCBZ. It could be concluded that TCBZ has no direct toxic effect on the hepatocytes. In experimental schistosomiasis TCBZ improved the liver pathology and enzymatic activity of the hepatocytes

Effect of GABA, muscimol and picrotoxin given in third ventricle on serum cholinesterases and monoamine oxidase and on plasma succinic dehydrogenase in rats.

Effect of injection in third ventricle of GABA, the GABA agonist muscimol, and the GABA antagonist picrotoxin on the activities of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and monoamine oxidase (MAO) in serum and succinic dehydrogenase (SDH) in plasma has been studied. Surprisingly, the AChE, BuChE, MAO and SDH enzymes activity were inhibited by GABA and muscimol, while they were enhanced by picrotoxin.