PH, intracellular

Cell Cycle Analysis and Kinetics Apoptosis Calcium Flux Chromosome Analysis Micronuclei Analysis Intracellular pH Intracellular Glutathione Oxidative Burst Cell Viability... 

Some evidence indicates that long-term use of topical antimicrobial agents may alter skin flora. Water content, humidity, pH, intracellular lipids, and rates of shedding help retain the protective barrier properties of the skin. When the barrier is compromised (e.g., by hand hygiene practices such as scrubbing), skin dryness, irritation, cracking, and other problems may result. Although the palmar surface of the hand has twice as many cell layers and the cells are >30 times thicker than on the rest of the skin, palms are quite permeable to water. 

Sodium bicarbonate 50-100 mEq IV over 2-5 min 30 min/2-6 hours Acute Raises serum pH Intracellular K redistribution... 

FIGURE 2.17 Anserine (AA/3-alanyl-3-methyl-L-hisddine) is an important dipeptide buffer in the maintenance of intracellular pH in some tissues. The structure shown is the predominant ionic species at pH 7. p. i (COOH)... 

Protein toxins acting intracellularly are often composed of two subunits (A/B model). One subunit is catalytic (A-subunit) and the other is responsible for binding and cell entry (B-subunit). Following binding to an extracellular membrane receptor, the toxins are endocytosed. From the endosomes, the A-subunit is directly (pH dqDendent) transferred into the cytosol (e.g., diphtheria toxin and anthrax toxin) or the toxin is transported in a retrograde manner via the golgi to the ER (e.g., cholera toxin), where translocation into the cytosol occurs [1]. 

Additional cellular events linked to the activity of blood pressure regulating substances involve membrane sodium transport mechanisms Na+/K.+ ATPase Na+fLi countertransport Na+ -H exchange Na+-Ca2+ exchange Na+-K+ 2C1 transport passive Na+ transport potassium channels cell volume and intracellular pH changes and calcium channels. 

The intracellular pH can also regulate the exchanger. [H+] strongly inhibits NCX activity under steady-state conditions, in fact, reduction in [pH] values, as little as 0.4, can induce a 90% inhibition of NCX activity. Such inhibitory action depends on the presence of intracellular Na+ ions, hence, the action exerted by H+ ions is pathophysiologically relevant with regards to brain and heart ischemia. 

Regulation of NHE3 involves many hormonal and physical mechanisms. Acutely, NHE3 activity is promoted by an increase in intracellular pH and this response is rapid. Furthermore, the increase in activity is proportional to the duration of acidification. Chronic acidification promotes recycling of NHE3 from subapi-cal endosomes to the plasma membrane. 

A series of bathing solutions mimicking the intracellular environment in fatigued muscle have been studied by Godt and Nosek (1989). Variations in ATP, ADP, PCr, and Cr contents had only marginal effects on the tension development compared to decreases in pH and increases in Pj. 

Juel, C. (1988), Intracellular pH recovery and lactate efflux in mouse soleus muscles stimulated in vitro The involvement of sodium/proton exchange and a lactate carrier. Acta Physiol. Scand. 132,... 

Sahlin, K., Alvestrand, A., Brandt, R., Hultman, E. (1978). Intracellular pH and bicarbonate concentration in human muscle during recovery from exercise. J. Appl. Physiol. 45,474—480. 

Westerblad, H. Lannergren, J. (1988). The relation between force and intracellular pH in fatigued, single Xenopus muscle fibers. Acta Physiol. Scand. 133, 83-89. 

Continuous and detailed knowledge of process conditions is necessary for the control and optimization of bioprocessing operations. Because of containment and contamination problems, this knowledge must often be obtained without sampling the process stream. At present, conditions such as temperatme, pressure, and acidity (pH) can be measured rapidly and accurately. It is more difficult to monitor the concentrations of the chemical species in the reaction medium, to say nothing of monitoring the cell density and intracellular concentrations of hundreds of compounds. 

Intracellular calcium elevation is monitored by fluorescent chelators developed by Tsien and coworkers. These indicators are loaded into cells the same way the pH indicators are. With Quin-2 (14), one of the first such probes developed, the quantum yield increases about fourfold when Ca binds to it. The second generation of Ca probes, Indo-1 and Fura-2 (15), are now being widely used in a variety of cell types. These probes are in most cases... 

There are several isomers of 1,2,3,4,5,6-hexachlorocyclohexane (HCH). The Y isomer is insecticidally active, whereas most of the others are relatively inactive. These compounds have been shown to activate inflammatory functions of neutrophils (35,36). Using Indo-1, we have characterized intracellular Ca mobilization in response to these compounds. Figure 9 shows the responses of cells labeled with Indo-1 to stimulation by y, < " P , and 6-HCH at a concentration of 260 pH. 

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