Insulin uptake, localization and production in previously insulin treated and untreatedTetrahymena. Data on the mechanism of hormonal imprinting

Abstract

Confocal microscopic experiments demonstrate the presence of insulin in Tetrahymena, observed also in earlier experiments. However, there is a broad spectrum of insulin-containing cells from the immunocytochemically insulin-free, to the strongly antibody-reactive ones. During 1 h of insulin treatment (imprinting) the cells gradually bind and take up insulin, and the process is slow. One minute after the start of treatment there is not difference in the number of insulin antibody-reactive cells and amount of insulin. After 5 or 10 min the cells bind and contain more insulin and after 1 h most of the cells are densely packed with the insulin antibody-reactive material. Insulin imprinting accelerates binding and uptake alike: 48 h after imprinting and 1 min after the start of the second treatment, more insulin is present on the surface and inside the cells, than after 10 min in the first-time treated cells. Theoretically, this effect of hormonal imprinting helps to maintain the species by facilitating molecular recognition and binding as well as uptake of useful molecules. The experiments also support previous observations on the parallel receptor-evoking (strengthening) and hormone-producing effect of hormonal imprinting.

Effect of insulin on in vitro fermentation activity of microrganism community of rumen ciliate culture

“…These biologically active molecules can induce and modify the activity of physiological processes such as growth (Christensen, 1993;Christensen et al, 1996aChristensen et al, ,b, 1998Csaba et al, 1985Csaba et al, , 1995Hegyesi and Csaba, 1997;Kristiansen et al, 1996;Shemarova et al, 2002), phagocytosis (Darvas and Csaba, 1990;Ko¨hidai et al, 1995;Kovacs et al, 1996;Schiess et al, 2001), metabolic pathways (Csaba and Lantos, 1976;Csaba and Nagy, 1976;Csaba and Ubornyak, 1982;Ko¨hidai and Csaba, 1985), movement (Csaba and Kovacs, 1993;Ko¨hidai et al, 1994Ko¨hidai et al, , 2000Ko¨hidai et al, , 2002Kovacs et al, 1994;Mugnaini et al, 1995), and secretion activity (Bencsath et al, 1994;Kovacs et al, 1992Kovacs et al, , 1997. Peptide type hormones causing these physiological effects are universal in multicellular systems, but many of them are present in unicellular organisms as well (Csaba and Kovacs, 2000;Csaba et al, 1999;De Pablo et al, 1986;Fulop and Csaba, 1991;Leroith et al, 1980Leroith et al, , 1981Leroith et al, , 1985Schwabe et al, 1983). The latter are not only able to synthesize hormones but they also have the ability to bind them (Christopher and Sundermann, 1992Christensen et al, 2003;Csaba, 1981;…”

Verification of epigenetic inheritance in a unicellular model system: multigenerational effects of hormonal imprinting

“…The unicellular ciliate, Tetrahymena , has a hormonal system, which regulates different functions (Csaba, 1985, 2000). The individual members of a population have very sensitive receptors to extremely low concentrations of hormones produced by the cells themselves in their watery milieu (Csaba et al, 2007), as well as signal pathways by which the reaction of the cell is stimulated (Christensen et al, 1998).…”

Dynamin-association with agonist-mediated sequestration of beta-adrenergic receptor in single-cell eukaryoteParamecium

“…As far as we know, there is no proof of the existence of dynamin-dependent sequestration in the unicellular eukaryotes, though protozoa have been found to be sensitive to a variety of neurotransmitters and neuropeptides (Le Roith et al, 1980;O'Neill et al, 1988;Wyroba, 1989;Renaud et al, 1995;Yang et al, 1997;Christensen et al, 1998;Vallesi et al, 1998;Csaba and Kovacs, 2000;Iwamoto et al, 2000;Delmonte Corrado et al, 2001). Some cases of receptor desensitization have been reported in protozoa but not the presence of G-protein-coupled kinase (Ayala and Kierszenbaum, 1990;Van Haastert et al, 1992;Xiao et al, 1999).…”