Oxidative stress, as determined by increased lipid peroxidation, has been implicated in the pathology of myotoxicity. As a model system to study the response of muscle to oxidative insults, we have studied the effects of diisopropylphosphorofluoridate (DFP)-induced muscle hyperactivity on levels of nitric oxide (NO) and energy metabolites in rat skeletal muscles. In in vivo experiments, citrulline levels as indicators of NO and NO synthase (NOS), and ATP and phosphocreatine (PCr) as indicators of mitochondrial dysfunction, were determined using HPLC methods 15 min, 30 min, 60 min, 2 h, and 24 h after intoxication. Within 15 min of DFP exposure, with onset of fasciculations, citrulline levels were significantly elevated in all three muscles [soleus, extensor digitorum longus (EDL), and diaphragm]. Maximum increases in citrulline (272-288%) were noted 60 min after DFP injection. At this time point, acetylcholinesterase activity was reduced by 90-96% (soleus < diaphragm < EDL). The levels of ATP and PCr were maximally reduced (30-43%), and total adenine nucleotides, and total creatine compounds showed declines. The findings revealed that the increase in NOS activity and NO was greater than the decrease of ATP and PCr. Since memantine (MEM) has been shown to reduce nerve and muscle hyperactivity, we have studied the possible protective effect of MEM on the DFP-induced biochemical changes. Pretreatment with MEM (18 mg/kg s.c.) and atropine sulfate (16 mg/kg s.c.), 60 min and 15 min, respectively, before DFP injection prevented the increase in citrulline and muscle hyperactivity and the decrease in ATP and PCr. These data suggest that free radical reactions by depleting high-energy phosphates may be initiating the cascade of events leading to myotoxicity during DFP-induced muscle hyperactivity.
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http://dx.doi.org/10.1007/s00204-002-0400-4 | DOI Listing |
J Oral Facial Pain Headache
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Department of Maxillofacial Surgery, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania.
Osteoma is a rare benign tumor primarily affecting the craniofacial skeleton. Coronary osteomas in the coronoid process are uncommon and asymptomatic until they affect mandibular function. This report presents a case of coronoid osteoma with its diagnosis, treatment and surgical approach.
View Article and Find Full Text PDFZhonghua Wei Zhong Bing Ji Jiu Yi Xue
December 2024
The Fifth Clinical Medical College, Henan University of Traditional Chinese Medicine, Zhengzhou 450003, Henan, China.
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Aesthetic Plast Surg
January 2025
Department of Plastic Surgery, Peking University 3rd Hospital, Beijing, 100191, China.
Background: Gender-affirming surgery (GAS) for transgender females developed relatively late and limited in China due to some reasons. To introduce GAS surgical experiences for Chinese transgender females is necessary.
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Mov Disord Clin Pract
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View Article and Find Full Text PDFOne of the long-standing questions in cell signaling field to identify and characterize key signaling nodes out of a complex network. Phospholipase Cγ1 ( ) was identified as the most frequently mutated gene in adult T-cell leukemia/lymphoma, suggesting a critical function of PLCG1 in driving T cell activation. However, it remains unclear how these mutations regulate T cell physiology and pathology.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!