Organisms surveil and respond to their environment using behaviors entrained by metabolic cues that reflect food availability. Mitochondria act as metabolic hubs and at the center of mitochondrial energy production is the protonmotive force (PMF), an electrochemical gradient generated by metabolite consumption. The PMF serves as a central integrator of mitochondrial status, but its role in governing metabolic signaling is poorly understood.
View Article and Find Full Text PDFDuring maturation oocytes undergo a recently discovered mitochondrial proteome remodeling event in flies, frogs, and humans. This oocyte mitochondrial remodeling, which includes substantial changes in electron transport chain (ETC) subunit abundance, is regulated by maternal insulin signaling. Why oocytes undergo mitochondrial remodeling is unknown, with some speculating that it might be an evolutionarily conserved mechanism to protect oocytes from genotoxic damage by reactive oxygen species (ROS).
View Article and Find Full Text PDFComp Biochem Physiol B Biochem Mol Biol
February 2024
Reactive oxygen species (ROS) are a key output of the skeletal muscle mitochondrial information processing system both at rest and during exercise. In skeletal muscle, mitochondrial ROS release depends on multiple factors; however, fiber-type specific differences remain ambiguous in part owing to the use of mitochondria from mammalian muscle that consist of mixed fibers. To elucidate fiber-type specific differences, we used mitochondria isolated from rainbow trout (Oncorhynchus mykiss) red and white skeletal muscles that consist of spatially distinct essentially pure red and white fibers.
View Article and Find Full Text PDFMitochondria are a main source of cellular energy. Oxidative phosphorylation (OXPHOS) is the major process of aerobic respiration. Enzyme complexes of the electron transport chain (ETC) pump protons to generate a protonmotive force (Δp) that drives OXPHOS.
View Article and Find Full Text PDFMitochondrial reactive oxygen species (ROS) homeostasis is intricately linked to energy conversion reactions and entails regulation of the mechanisms of ROS production and removal. However, there is limited understanding of how energy demand modulates ROS balance. Skeletal muscle experiences a wide range of energy requirements depending on the intensity and duration of exercise and therefore is an excellent model to probe the effect of altered energy demand on mitochondrial ROS production.
View Article and Find Full Text PDFComp Biochem Physiol B Biochem Mol Biol
March 2022
Mitochondria are key cellular sources of reactive oxygen species (ROS) and contain at least 12 known sites on multiple enzymes that convert molecular oxygen to superoxide and hydrogen peroxide (HO). Quantitation of site-specific ROS emission is critical to understand the relative contribution of different sites and the pathophysiologic importance of mitochondrial ROS. However, factors that affect mitochondrial ROS emission are not well understood.
View Article and Find Full Text PDFComp Biochem Physiol C Toxicol Pharmacol
February 2022
Aquatic organisms are frequently exposed to multiple stressors including low dissolved oxygen (O) and metals such as cadmium (Cd). Reduced O concentration and Cd exposure alter cellular function in part by impairing energy metabolism and dysregulating reactive oxygen species (ROS) homeostasis. However, little is known about the role of mitochondrial glycerol 3-phosphate dehydrogenase (mGPDH) in ROS homeostasis in fish and its response to environmental stress.
View Article and Find Full Text PDFFree Radic Biol Med
February 2021
Oxygen (O) deprivation and metals are common environmental stressors and their exposure to aquatic organisms can induce oxidative stress by disrupting cellular reactive oxygen species (ROS) homeostasis. Mitochondria are a major source of ROS in the cell wherein a dozen sites located on enzymes of the electron transport system (ETS) and substrate oxidation produce superoxide anion radicals (O˙‾) or hydrogen peroxide (HO). Sites located on ETS enzymes can generate ROS by forward electron transfer (FET) and reverse electron transfer (RET) reactions; however, knowledge of how exogenous stressors modulate site-specific ROS production is limited.
View Article and Find Full Text PDFThe age-related morphological changes of the testes in light ecotype Nigerian indigenous chicken were evaluated in this study using gross anatomical, histological and histomorphometric techniques. The results showed that the testes of 3- to 9-month-old birds were light pink while testes of sexually mature chicken were creamy white in colour. The left and right testicular weight, length, diameter, circumference and the organosomatic indices increased significantly (p < .
View Article and Find Full Text PDFThis study investigated the effects of administration of monosodium L-glutamate (MSG) on serum gonadotrophin-releasing hormone (GnRH), luteinising hormone (LH), testosterone and total cholesterol (TC), cauda epididymal sperm reserves (CESR) and testicular histomorphology of adult male albino rats. Eighty-four rats, randomly assigned to 7 groups of 12 rats each, were used for the study. Varying low doses (0.
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