Although phospholipase C hydrolysis of polyphosphoinositides constitutes one of the major second messenger pathways in animal cells, its participation in signal transduction in higher plants has not been established. To determine whether activation of phosphatidylinositol-directed phospholipase C might be involved in signaling the elicitor-induced oxidative burst in plants, suspension-cultured ...

INTRODUCTION AND METHODS. Inositol-l,4,5-trisphosphate (IP3) is an important second messenger which mobilizes intracellular calcium stores (1). It has been demonstrated that in various tissues, including the retina, stimulation of several receptor types activates hydrolysis of membrane phospholipids with concomitant formation of IP3 (1-3). Data on effects of dopamine (DA) on IP3 production are ...

Fertilization initiates a transient increase in intracellular Ca2+ principally by Ca2+ release from intracellular stores. Possible multiple Ca2+ stores and multiple receptor regulation of the same store have been reported. Here we report the presence of at least two independent intracellular Ca2+ stores in the sea urchin egg, which are released during fertilization. Ca2+ release from one store ...

Generation of intracellular Ca2+ signals in response to Ca(2+)-mobilizing stimuli is a critical event in the control of many cellular processes. Inositol 1,4,5-trisphosphate (IP3) represents a dominant second messenger subserving the release of Ca2+ from intracellular store sites. The protein on the surface of which the IP3 receptor is located comprises an IP3-gated Ca2+ channel, and binding of...

Ca2+ signals associated with action potentials (APs) and metabotropic glutamate receptor (mGluR) activation exert distinct influences on neuronal activity and synaptic plasticity. However, it is not clear how these two types of Ca2+ signals are differentially regulated by neurotransmitter inputs in a single neuron. We investigated this issue in dopaminergic neurons of the ventral midbrain using...

Ca2+ release from the envelope of isolated pancreatic acinar nuclei could be activated by nicotinic acid adenine dinucleotide phosphate (NAADP) as well as by inositol 1,4,5-trisphosphate (IP3) and cyclic ADP-ribose (cADPR). Each of these agents reduced the Ca2+ concentration inside the nuclear envelope, and this was associated with a transient rise in the nucleoplasmic Ca2+ concentration. NAADP...

We described methods for imaging the IP3-induced Ca2+ release in Ca2+ storage organelles. IP3-induced changes in Ca2+ concentrations within Ca2+ stores ([Ca2+]L) in permeabilized HSY cells were monitored using the low affinity Ca2+ indicators, mag-fura-2 and mag-fura-red. The ratio images of mag-fura-2 were used to estimate the [Ca2+]L in the store. The apparent [Ca2+]L was 300-1000 microM at t...

Estradiol (E2) accelerates egg transport by a nongenomic action, requiring activation of estrogen receptor (ER) and successive cAMP and IP3 production in the rat oviduct. Furthermore, E2 increases IP3 production in primary cultures of oviductal smooth muscle cells. As smooth muscle cells are the mechanical effectors for the accelerated oocyte transport induced by E2 in the oviduct, herein we de...

Peritoneal carcinomatosis results from dissemination of solid tumors in the peritoneal cavity, and is a common site of metastasis in patients with carcinomas of gastrointestinal or gynecological origin. Peritoneal carcinomatosis treatment is challenging as poorly vascularized, disseminated peritoneal micro-tumors are shielded from systemic anticancer drugs and drive tumor regrowth. Here, we des...