Hormonal imprinting usually takes place perinatally at the first encounter between the developing receptor and its target hormone, determining the future binding capacity of the receptor for life. Molecules similar to a hormone can cause faulty imprinting also with life-long consequences. Hormone production of the imprinted cell is also durably influenced. In cytogenic organs imprinting can also be provoked in adulthood. At present the effect of a single terfenadine treatment in adult rats on the histamine content of peritoneal cells (lymphocytes, mast cells and the monocyte-macrophage-granulocyte group), white blood cells (lymphocytes, granulocytes, monocytes) and thymic lymphocytes was studied 3 weeks after treatment to clarify the effect of prolonged treatment with an antihistamine in adulthood. The cells were studied by flow cytometric analysis. Peritoneal mast cells contained significantly more and thymic lymphocytes significantly less histamine than controls. In the other cells the differences were not significant. The results support earlier observations on the effect of antihistamines on mast cell histamine release (inhibition) and call attention to the fact that this effect is durable (hormonal imprinting provoked in adults).

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Acute and delayed effect of (-) deprenyl and (-) 1-phenyl-2-propylaminopentane (PPAP) on the serotonin content of peritoneal cells (white blood cells and mast cells).

Acute and delayed (hormonal imprinting) effect of (-) deprenyl and its derivative without MAO-B inhibitory activity (-) PPAP, were studied on cells of the peritoneal fluid (lymphocytes, monocytes, granulocytes and mast cells) by flow cytometric and confocal microscopic analysis. Thirty minutes after treatment of 6-week-old female animals, deprenyl was ineffective while PPAP significantly increased the serotonin level of these cells. Three weeks after treatment at weaning, deprenyl drastically decreased the serotonin level of each cell type, while PPAP moderately but significantly increased the serotonin level of monocytes, granulocytes and mast cells. This means that the two related molecules have different effects on the immune cells, which seem to be independent of MAO-B inhibition. The experiments emphasize the necessity of studying the prolonged effects of biologically active molecules, even if they are without acute effects. As serotonin is a modulator of the immune system, the influence on immune cells of the molecules studied can contribute to their enhancing effect.

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Effect of drugs affecting microtubular assembly on microtubules, phospholipid synthesis and physiological indices (signalling, growth, motility and phagocytosis) in Tetrahymena pyriformis.

Structural changes of microtubules, incorporation of radioactively labelled components into phospholipids, cell motility, growth and phagocytosis were studied under the effect of four drugs affecting microtubular assembly: colchicine, nocodazole, vinblastine and taxol. Although the first three agents influence microtubules in the direction of depolymerization and the fourth stabilizes them, their effects on the structure of microtubules cannot be explained by this. Using confocal microscopy after an acetylated anti-tubulin label, in nocodazole- and colchicine-treated cells, the basal body cages disappear and longitudinal microtubules (LM) became thinner without changing transversal microtubules (TM). After taxol treatment LM also became thinner, however TM disappeared. Under the effect of vinblastine TM became thinner, without influencing LM. These drugs influence the incorporation of components ([(3)H]-serine, [(3)H]-palmitic acid and (32)P) into phospholipids, however their effect is equivocal and cannot be consequently coupled with the effect on the microtubules. Nocodazole, vinblastine and taxol significantly reduced the cell's motility, however colchicine did so to a lesser degree. Vinblastine and nocodazole totally inhibited, and taxol significantly decreased cell growth, while colchicine in a lower concentration increased the multiplication of cells. Phagocytosis was not significantly influenced after 1 min, but after 5 min all the agents studied (except colchicine) significantly inhibited phagocytosis. After 15 and 30 min each molecule caused highly significant inhibition. The experiments demonstrate that drugs affecting microtubular assembly dynamics influence differently the diverse (longitudinal, transversal etc.) microtubular systems of Tetrahymena and also differently influence microtubule-dependent physiological processes. The latter are more dependent on microtubular dynamics than are changes in phospholipid signalling.

Acetylation↗

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Effect of serotonin-acting agents on the serotonin content of immune cells. A peculiar observation.

The effect of the tryptophan hydroxylase inhibitor, PCPA methylester, the serotonin reuptake inhibitor fluoxetine and MAO-A inhibitor clorgyline on the serotonin content of rat immune cells was studied, using labelled antibodies and flow cytometry. Each molecule significantly increased in males the serotonin concentration of peritoneal lymphocytes and the monocyte-macrophage-granulocyte group (mo-gran), however the agents were ineffective towards mast cells. In females fluoxetine and clorgyline increased the serotonin concentration in peritoneal lymphocytes and mo-gran. Fluoxetine also increased the serotonin level in mast cells. Thymus was absolutely resistant to the drugs in both genders. The results call attention (1) to the reverse effect of serotonin-acting agents on immune cells, (2) to the influence of the milieu where the cell is located and (3) the effect of gender.

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Effect of starvation on insulin production and insulin binding in Tetrahymena.

Tetrahymena pyriformis GL was starved for 24 h and then the immunologically demonstrable insulin content and FITC-insulin binding were measured by flow cytometry and localization was studied by confocal microscopy. The amount of endogeneous insulin as well as FITC insulin binding, was highly significantly elevated. Glucose feeding for 30 min abolished the elevation of FITC-insulin binding. In starved cells, insulin-binding sites disappeared from the surface and FITC-insulin was bound inside the cells, within large food vacuoles. Endogeneous insulin was dispersed in the cytoplasm both in the control and starved cells and food vacuoles did not contain it. The results call attention to the stimulatory effect of starvation on insulin production in Tetrahymena, in parallel with the internal storage of insulin receptors, which points to an autocrine mechanism.

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gamma-L-glutamyl-taurine (Litoralon) prevents the micronucleus formation induced by mitomycin C.

We have examined whether gamma-L-glutamyl-taurine (Litoralon) could prevent the genotoxic action of mitomycin C (MMC) in the rat bone marrow cells using the micronucleus test. Litoralon (0.83 mg/kg) administered concurrently with MMC (0.75 mg/kg) did not exhibit any protective action. Pretreatment with a single dose (0.83 mg/kg) of Litoralon 24 h before the administration of MMC (0.75 mg/kg) prevented the micronucleus-inducing effect of MMC. There was no difference between the efficiencies of a single and multiple Litoralon pretreatments. Since Litoralon is known to exhibit vitamin A-like activity and stimulation of poly-ADP-ribose synthesis, it is presumed that either one of these 2 properties separately, or both in conjunction, can be responsible for the inhibition of micronucleus formation.

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A lectin-like molecule is discharged from mucocysts of Tetrahymena pyriformis in the presence of insulin.

By use of a monoclonal antibody directed against purified lectin from the sponge Geodia cydonium it was demonstrated that the mucocysts of Tetrahymena pyriformis contain a substance immunologically similar to that found in G. cydonium. In extracts of T. pyriformis the monoclonal antibody recognizes a 36 kDa protein; binding could be abolished by adsorption of the antibody with (i) crude extract, (ii) purified lectin from G. cydonium and (iii) a 29 aa long peptide. In addition the data show that 10(-6) M of insulin causes first the release of mucocyst material, which reacts with the lectin antibody, and second its subsequent redistribution on the surface of the somatic cilia and the oral field.

Amino Acid Sequence↗

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Insulin binding sites induced in the Tetrahymena by rat liver receptor antibody.

Tetrahymena cells treated with purified rabbit antibodies to rat hepatocellular membrane exhibited a considerable increase in binding capacity on reexposure to the antibody 24 h later. Insulin binding was similarly enhanced by preexposure to the antibody, and vice versa, preexposure to insulin enhanced the later binding of rat liver receptor antibodies. This suggests that (1) the Tetrahymena and the rat possess similar insulin receptors, and (2) the receptor antibody is also able to induce imprinting for itself as well as for insulin. Concanavalin-A, noted for binding overlap with insulin, failed to induce imprinting either for insulin or for antibodies to receptors, whereas the latter did induce imprinting for Concanavalin-A.

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Effect of tuftsin on the phagocytotic activity of the unicellular Tetrahymena. Does primary interaction develop imprinting?

The natural mammalian phagocytosis stimulator tetrapeptide tuftsin stimulated also the phagocytosis of the unicellular Tetrahymena. The selectivity of the Tetrahymena was not complete, as threonin-free tuftsin provoked a greater response. Treatment with tuftsin did not develop functional imprinting, however the binding capacity of cell membrane significantly increased after the first treatment.

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Effect of the thymus storage factor (TSF) on the blood sugar and insulin level.

The rat thymus extract prepared with physiological NaCl solution causes--by its TSF component--an increase of the blood sugar level. After sugar loading in TSF-treated animals, the blood sugar level becomes gradually higher and the insulin secretion diminishes as compared to the control animals. Thymectomy moderates but does not inhibit the TSF decreasing effect on the insulin level. Consequently, TSF primarily causes a decrease of the blood insulin level which correlates with a rise of the blood sugar level.

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A model for histone-nonhistone control of ontogenesis.

The co-operation of histones and nonhistones in the known models can sufficiently explain the control of processes occurring within the differentiated cells. To give an explanation--on the same basis--for changes during ontogenesis and for manifestation of the development's program, a new model is needed which supposes the existence of a programming as well as a realizing system. At the start, the realizing system becomes repressed by histones. After this, the programming system gives orders for the production of nonhistones. These latter then activate the adequate (definite) operator of the realizing system and direct, simultaneously, a further programming gene for the production of a specific nonhistone needed for the following step of the program. Further on, the model could give an explanation for the manner in which the differentiated features of the cell are conserved during mitosis. One may suppose, in this case, that the new DNA strands become without delay wholly repressed. The phase-specific nonhistones--characterizing the cell's ontogenesis and produced by direction of the programming genes--will then displace the histones from the adequate DNA-sites.

Histones↗

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Comparative examination of melatonin and TSH effects evoked in rat and in frog.

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Effect of neonatal triiodothyronine (T3) treatment (hormonal imprinting) on the sexual behavior of adult rats.

Neonatal treatment with triiodothyronine increased the mounting and decreased the intromission of male rats. Number of inactive rats and number of ejaculations were not changed. In females a non-significant increase of Meyerson index was observed. Considering earlier results, the experiment demonstrates that neonatal T3 treatment can influence different receptors for life. The results also supports earlier observations on the sexual behavioral effect of perinatal treatment with molecules being structurally different from steroids however able to bind to receptors of the steroid receptor superfamily.

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