The intestinal brush border (BB) Na+/H+ exchanger isoform 3 (NHE3) is acutely inhibited by elevation in the concentration of free intracellular Ca2+ ([Ca2+]i) by the cholinergic agonist carbachol and Ca2+ ionophores in a protein kinase C (PKC)-dependent manner. We previously showed that elevating [Ca2+]i with ionomycin rapidly inhibited NHE3 activity and decreased the amount of NHE3 on the plas...

PURPOSE Mucins are important structural and functional components of the precorneal tear film, yet little is known of their composition and synthesis. The mRNAs of MUC1, MUC4, and MUC5AC have previously been identified in human conjunctiva. Of these, only MUC5AC mRNA appears to be associated with goblet cells. The purpose of the this study was to quantify MUC5AC transcript levels, to identify M...

The murine T lymphoma line, LBRM-33 1A5, requires synergistic signals delivered by phytohemagglutinin (PHA) and interleukin 1 (IL1) for activation to high level interleukin 2 production. The activation signals provided by PHA and IL1 were replaced by the Ca2+ ionophore, ionomycin, and the phorbol ester, 120-tetradecanoylphorbol 13-acetate (TPA), respectively. These observations upported a ...

Dihydropyrimidine dehydrogenase is the most extensively investigated predictive marker for individual response to 5fluorouracil. Clinical responses to the anticancer agent, along with various reports, have clearly shown that dihydropyrimidine dehydrogenase activity is closely correlated to its mRNA levels, but the regulatory mechanisms of its expression have remained unclear. We attempted to cl...

The stimulation of polymorphonuclear leukocytes (PMNs) by chemoattractants triggers a rapid rise in cytosolic free calcium concentration(s) ([Ca2+]i), which quickly returns to base line, suggesting a role for calcium removal in the homeostasis of activated PMNs. To investigate cytosolic calcium homeostasis, PMNs were treated with a fluoroprobe and ionomycin to induce a sustained elevation of [C...

In several tissues, transient receptor potential vanilloid 4 (TRPV4) channels are involved in the response to hyposmotic challenge. Here we report TRPV4 protein in porcine lens epithelium and show that TRPV4 activation is an important step in the response of the lens to hyposmotic stress. Hyposmotic solution (200 mosM) elicited ATP release from intact lenses and TRPV4 antagonists HC 067047 and ...

The aim of this study was to identify an optimal method for the parthenogenetic activation of mouse oocytes. Ethanol (EH), strontium chloride (SrCl2) and ionomycin calcium salt were each combined with cytochalasin B to induce the parthenogenetic activation of CD-1® mouse oocytes. Among the EH combination groups, the blastocyst formation and hatching rates of the group that was activated with EH...

The dopaminergic receptor D1 activates and the muscarinic acetylcholine receptor (mAChR) M4 inhibits adenylyl cyclase (AC) and thereby cAMP production through the trimeric Gas and Gai/o proteins, respectively (Wess et al, 2007). D1 and M4 are coexpressed in striatal output neurons, where M4 antagonizes D1 signalling as recently pinpointed by conditional M4 knockout in D1-expressing neurons (Jeo...

STUDY QUESTION Does the application of three different artificial activating stimuli lead to a difference in pre- and post-implantation embryo development in the wobbler mouse, a mouse model with oocyte activation deficient round-headed sperm cells similar to human globozoospermia? SUMMARY ANSWER No gross differences were found between strontium chloride, electrical pulses or ionomycin with r...