Search results for "Sarcoplasm"
showing 6 items of 26 documents
Effects of sulindac sulfide on the membrane architecture and the activity of gamma-secretase.
2007
gamma-Secretase is a membrane-embedded multi-protein complex that catalyzes the final cut of the Alzheimer's disease-related amyloid precursor protein (APP) to amyloid-beta peptides of variable length (37-43 amino acids) via an unusual intramembrane cleavage. Recent findings propose that some commonly used non-steroidal anti-inflammatory drugs (NSAIDs) have the ability to modulate specifically gamma-secretase activity without inhibiting the enzyme as a whole. These drugs may shift the processing of APP from the longer amyloid-beta 42 peptide towards shorter, less fibrillogenic and less toxic amyloid-beta species. We hypothesize that gamma-secretase activity, as an enzyme that is strictly as…
Synthesis, computational docking and biological evaluation of celastrol derivatives as dual inhibitors of SERCA and P-glycoprotein in cancer therapy.
2021
Abstract A series of eleven celastrol derivatives was designed, synthesized, and evaluated for their in vitro cytotoxic activities against six human cancer cell lines (A549, HepG2, HepAD38, PC3, DLD-1 Bax-Bak WT and DKO) and three human normal cells (LO2, BEAS-2B, CCD19Lu). To our knowledge, six derivatives were the first example of dipeptide celastrol derivatives. Among them, compound 3 was the most promising derivative, as it exhibited a remarkable anti-proliferative activity and improved selectivity in liver cancer HepAD38 versus human normal hepatocytes, LO2. Compound 6 showed higher selectivity in liver cancer cells against human normal lung fibroblasts, CCD19Lu cell line. The Ca2+ mob…
Expression of different isoforms of nitric oxide synthase in experimentally denervated and reinnervated skeletal muscle.
1997
Denervated muscle fibers express enhanced levels of stress and apoptosis-associated proteins and undergo apoptosis. In experimentally denervated and reinnervated rat facial muscle, we now evaluate changes in the expression patterns of different isoforms of nitric oxide synthase (NOS)-generating nitric oxide (NO), which mediates oxidative stress and apoptosis. Physiological expression of NOS corresponds to a constant sarcolemmal staining pattern for neuronal NOS (nNOS) and a patchy sarcolemmal and weak sarcoplasmic labeling for the endothelial NOS-isoform, with no expression for inducible NOS (iNOS). Denervated muscle displayed distinct downregulation of nNOS with preserved expression of dys…
Morphometry of myocardial apex in endurance-trained mice of different ages
1979
Mitochondrial volume density, surface density of the outer mitochondrial membrane, the mean number and size of mitochondria, and the mean surface density of crista membranes together with the volume densities of myofibrils and sarcoplasmic space were morpho-metrically analyzed in cardiac muscle of two groups of sedentary control mice aged 3 and 7 months, and in two groups of mice trained either 1 month rather intensely or 4 months moderately. Of the calculated mitochondrial variables only the surface density of the outer mitochondrial membrane differed between the older controls and the older trained animals, the density being slightly smaller in the trained group. The myofibrillar volume d…
Lipid peroxidation capacities in the myocardium of endurance-trained rats and mice in vitro.
1992
The endurance-training programme in Experiment 1 (Exp. 1) consisted of a total swimming time of 149–159 h per male Han Wistar rat and in Experiment 2 (Exp. 2) the male NMRI-mice run on a treadmill at a speed of 25 m min-1 1 h per day, 5 days a week for 3 weeks. One group of the rat hearts was perfused with 0.3 mm cumene hydroperoxide (CumOOH) while the others were fractioned (mitochondria, sarcolemma and sarcoplasmic reticulum) and these cell fractions and homogenates were used to determine the total concentration of peroxidative lipids and the susceptibility to lipid peroxidation. The perfusion with CumOOH caused the release of thiobarbituric acid reactive substances (TBARS) into the perfu…
Possible role of cyclic AMP in the relaxation process of mammalian heart: effects of dibutyryl cyclic AMP and theophylline on potassium contractures …
1976
The effect of dibutyryl cyclic AMP (DB-c-AMP; 3 X 10(-4)-3 X 10(-3) M) on electrically induced twitch and high potassium (142.4 mM KCl)-induced contracture tension was studied in papillary muscles from normal and reserpinized cats ([Ca]0 1.8 mM; 25 degrees C; pH 7.4). In both groups of preparations, the increase in twitch tension evoked by DB-c-AMP was accompanied by an abbreviation of the time to peak force and of relaxation time. In the same preparations, the high potassium contracture was markedly depressed by DB-c-AMP in a concentration-dependent manner. Similar results were obtained with the N6-monobutyryl derivative of cyclic AMP. The relaxing effects of the cyclic nucleotides on KCl …