The effect of fungal elicitors and calcium-channel modulators on the anthocyanin production in callus cultures of Daucus carota was studied. It was found that the addition of fungal elicitors resulted in higher anthocyanin accumulation on the 3rd day of culture, but they resulted in lower levels of anthocyanin on the 21st day. Fungal elicitor treatment also affected growth of the cultures, as e...

Of all the components of the culture medium, only CaCl2 induces DNA replication when added to resting cultures of Balb/c 3T3 cells. The effect is present even in a serum-free medium. Increasing the Ca++ concentration above the standard 1.8 mM in the medium of a new culture increases the total number of cells ultimately produced, without affecting the initial cell growth rate. This effect is syn...

It is known that PMA (phorbol-12-myristate-13-acetate) can activate the classical and novel protein kinase C isoenzymes (cPKC alpha, beta, gamma and nPKC delta, epsilon, eta, theta), while the calcium ion can induce only the activity of cPKC. Calcineurin binding protein (Cabin 1) belongs to the group of endogenous inhibitors of calcineurin. Cabin 1 becomes hyperphosphorylated in response to PKC...

Calcium-specific ionophores are used widely to stimulate Ca2+-dependent secretion from cells on the assumption that permeabilization of the cell membranes to Ca2+ ions leads to a rise in concentration of cytosolic Ca2+ ([Ca”+li), which in turn serves as a signal for secretion. In this way, events that precede mobilization of Ca2+ ions via receptor stimulation are bypassed. One such event is tho...

Interleukin-2 (IL-2) gene regulation was investigated in primary cultures of highly purified human peripheral blood CD28+ T cells. Two discrete mechanisms for induction of T-cell proliferation could be distinguished by examining cell cycle progression and the expression of the IL-2 gene. Stimulation of cells by CD3 MoAb induced only transiently expressed, small amounts of IL-2 mRNA that was com...

BACKGROUND Fertilization failure is one of the most problems in assisted reproduction technology (ART). OBJECTIVE The aim of this study was the evaluation of oocytes activation by addition of calcium ionophore in unfertilized oocytes in ICSI cycles. MATERIALS AND METHODS This study was done on 15 ICSI cycles (stimulated with standard long protocol). Mature retrieved oocytes with normal morp...

Analysis of viral glycoprotein expression on surfaces of monensin-treated cells using a fluorescence-activated cell sorter (FACS) demonstrated that the sodium ionophore completely inhibited the appearance of the vesicular stomatitis virus (VSV) G protein on (Madin-Darby canine kidney) MDCK cell surfaces. In contrast, the expression of the influenza virus hemagglutinin (HA) glycoprotein on the s...

The alkaloid neurotoxins aconitine, veratridine, grayanotoxin, and batrachotoxin activate the action potential Na+ ionophore by interaction with a common binding site. Concentration-response curves are fit by simple Langmuir isotherms. The fraction of Na+ ionophores activated at saturating concentrations of neurotoxin are: aconitine, 0.02; veratridine, 0.08; grayanotoxin, 0.51; and batrachotoxi...