Acidic extracellular pH is characteristic of the cell microenvironment in several important physiological and pathological contexts. Although it is well established that acidic extracellular pH can have profound effects on processes such as cell adhesion and migration, the underlying molecular mechanisms are largely unknown. Integrin receptors physically connect cells to the extracellular matri...

The effect of alterations in extracellular pH on cellular and humoral immune function is reviewed. Because acidic pH predominates at inflammatory loci and other sites of immune activity, most studies to date focus on the effect of acidic rather than alkaline pH. Investigations on polymorphonuclear leukocytes demonstrate mainly inhibition of chemotaxis, respiratory activity, and bactericidal cap...

TRPV1 (vanilloid receptor 1) receptors are activated by a variety of ligands such as capsaicin, as well as by acidic conditions and temperatures above 42 degrees C. These activators can enhance the potency of one another, shifting the activation curve for TRPV1 to the left. In this study, for example, we observed an approximately 10-fold shift in the capsaicin EC50 (640 nM to 45 nM) for rat TRP...

The present study characterises an acidic protease purified from the Rhizopus stolonifer strain, RN-11. The acidic protease with a 70 kDa molecular weight, was stable within pH 2-4 at temperatures 40-50°C. The temperature and pH value conducive to optimal catalytic activity were pH 2.5 and 50°C, respectively. Treatment with 5 mmol metal ions showed that the acidic protease was activated by Na, ...

The aim of this study was to investigate pH-dependent passive and active transport of acidic drugs across Caco-2 cells. Therefore, the bidirectional pH-dependent transport of two acidic drugs, indomethacin and salicylic acid, across Caco-2 cells was studied in the physiological pH range of the gastrointestinal tract. The transport of both drugs decreased with increased pH, as expected from the ...

We cloned, expressed, and purified the hdeB gene product, which belongs to the hdeAB acid stress operon. We extracted HdeB from bacteria by the osmotic-shock procedure and purified it to homogeneity by ion-exchange chromatography and hydroxyapatite chromatography. Its identity was confirmed by mass spectrometry analysis. HdeB has a molecular mass of 10 kDa in sodium dodecyl sulfate-polyacrylami...

BACKGROUND Local acidosis has been demonstrated in ischemic tissues and at inflammatory sites. RESULTS Acidic extracellular pH triggers NLRP3 inflammasome activation and interleukin-1β secretion in human macrophages. CONCLUSION Acidic pH represents a novel danger signal alerting the innate immunity. SIGNIFICANCE Local acidosis may promote inflammation at ischemic and inflammatory sites. L...

Stricture of coronary arteries is closely related to ischemic heart disease. The purpose of this study was to examine whether changes in pH caused contraction of rat coronary arteries, as determined using Langendorff perfused hearts. Changing the pH of the perfusate increased perfusion pressure as an indication of the contractile state of coronary arteries. Alkaline pH-induced increase of perfu...