The process of store-operated calcium entry (SOCE) leads to refilling the endoplasmic reticulum (ER) with calcium ions (Ca2+) after their release into the cytoplasm. Interactions between (ER)-located Ca2+ sensors (stromal interaction molecule 1 [STIM1] and STIM2) and plasma membrane-located Ca2+ channel-forming protein (Orai1) underlie SOCE and are well described in non-excitable cells. In neur...

Leptin can exert its potent appetite-suppressing effects via activation of hypothalamic proopiomelanocortin (POMC) neurons. It depolarizes POMC neurons via activation of a yet unidentified nonselective cation current. Therefore, we sought to identify the conductance activated by leptin using whole-cell recording in EGFP-POMC neurons from transgenic mice. The TRPC channel blockers SKF96365 (1-[b...

The prelimbic region of the medial prefrontal cortex (mPFC) is a brain area crucial for memory, attention, and decision making. It has been shown that α2-adreneoceptors (α2-ARs) play a powerful role in regulating memory and attention functions in this region. Since many studies have demonstrated the impairment effect of morphine on memory through mPFC, we aimed to investigate the possible inter...

Vasomotion describes oscillations of arterial vascular tone due to synchronized changes of intracellular calcium concentrations. Since increased calcium influx into vascular smooth muscle cells from spontaneously hypertensive rats (SHR) has been associated with variances of transient receptor potential canonical (TRPC) channels, in the present study we tested the hypothesis that increased vasom...

Enhanced spontaneous contractions are associated with overactive bladder. Elevated levels of reactive oxygen species might contribute to enhanced spontaneous contractions. We investigated the regulation of spontaneous contractions and the effects of hydrogen peroxide (H2O2) in intact rat bladder strips. The spontaneous contractions were measured using a tissue bath system. The vehicle or the sp...

Chronic hypoxia (CH) causes pulmonary vasoconstriction because of increased pulmonary arterial smooth muscle cell (PASMC) contraction and proliferation. We previously demonstrated that intracellular Ca concentration ([Ca ]i) was elevated in PASMCs from chronically hypoxic rats because of Ca 2 influx through pathways other than L-type Ca channels and that development of hypoxic pulmonary hyperte...

The purpose of this study was to investigate the role of extracellular Ca++ influx via L-type and non-L-type Ca++ channels in thromboxane A2 receptor-mediated contraction. In intact rat aorta, U46619, a selective thromboxane A2 receptor agonist, induced concentration-dependent increases in intracellular Ca++ ([Ca++]i) and contraction (EC50 values of 5.5 and 6.1 nM, respectively). U46619 (10 nM)...

The peripheral airway innervation of the lower respiratory tract of mammals is not completely functionally characterized. Recently, we have shown in rats that precision-cut lung slices (PCLS) respond to electric field stimulation (EFS) and provide a useful model to study neural airway responses in distal airways. Since airway responses are known to exhibit considerable species differences, here...

The Streptococcus pneumoniae toxin pneumolysin belongs to the group of cholesterol-dependent cytolysins. It produces rapid cell lysis at higher concentrations or apoptosis at lower concentrations. In cell membranes, it forms prepores and pores. Here, we show that sublytic concentrations of pneumolysin produce rapid activation of Rho and Rac GTPases and formation of actin stress fibers, filopodi...

Nuñez, Marco T., and Victoria Tapia. Transferrin stimulates iron absorption, exocytosis, and secretion in cultured intestinal cells. Am. J. Physiol. 276 (Cell Physiol. 45): C1085– C1090, 1999.—The cellular mechanism by which basolateral transferrin (Tf) produces an increase in apical-to-basolateral Fe flux in Caco-2 cells was analyzed. After a pulse of 59Fe from the apical medium, three types o...