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The unicellular ciliate, Tetrahymena has receptors for hormones of the higher ranked animals, these hormones (e.g. insulin, triiodothyronine, ACTH, histamine, etc.) are also produced by it and it has signal pathways and second messengers for signal transmission. These components are chemically and functionally very similar to that of mammalian ones. The exogenously given hormones regulate different functions, as movement, phagocytosis, chemotaxis, cell growth, secretion, excretion and the cells’ own hormone production. The receptors are extremely sensitive, certain hormones are sensed (and response is provoked) at 10−21 M concentration, which makes likely that the function could work by the effect of hormones produced by the Tetrahymena itself. The signal reception is selective, it can differentiate between closely related hormones. The review is listing the hormones produced by the Tetrahymena, the receptors which can receive signals and the signal pathways and second messengers as well, as the known effects of mammalian hormones to the life functions of Tetrahymena. The possible and justified role of hormonal system in the Tetrahymena as a single cell and inside the Tetrahymena population, as a community is discussed. The unicellular hormonal system and mammalian endocrine system are compared and evolutionary conclusions are drawn.

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The thymus develops from an endocrine area of the foregut, and retains the ancient potencies of this region. However, later it is populated by bone marrow originated lymphatic elements and forms a combined organ, which is a central part of the immune system as well as an influential element of the endocrine orchestra. Thymus produces self-hormones (thymulin, thymosin, thymopentin, and thymus humoral factor), which are participating in the regulation of immune cell transformation and selection, and also synthesizes hormones similar to that of the other endocrine glands such as melatonin, neuropeptides, and insulin, which are transported by the immune cells to the sites of requests (packed transport). Thymic (epithelial and immune) cells also have receptors for hormones which regulate them. This combined organ, which is continuously changing from birth to senescence seems to be a pacemaker of life. This function is basically regulated by the selection of self-responsive thymocytes as their complete destruction helps the development (up to puberty) and their gradual release in case of weakened control (after puberty) causes the erosion of cells and intercellular material, named aging. This means that during aging, self-destructive and non-protective immune activities are manifested under the guidance of the involuting thymus, causing the continuous irritation of cells and organs. Possibly the pineal body is the main regulator of the pacemaker, the neonatal removal of which results in atrophy of thymus and wasting disease and its later corrosion causes the insufficiency of thymus. The co-involution of pineal and thymus could determine the aging and the time of death without external intervention; however, external factors can negatively influence both of them.

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Tetrahymena as a model cell for receptor research . Int Rev Cytol 95 , 327 – 377 ( 1985 ). 8. Csaba , G. : The hormonal system of the unicellular Tetrahymena: A

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. Endocrinol. Invest., 1985, 8 (6), 557–559. 4 Csaba, G.: The hormonal system of the unicellular Tetrahymena: a review with evolutionary aspects. Acta Microbiol. Immunol. Hung., 2012

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Scolexin is one of the bacterial induced hemolymph proteins of tobacco hornworm (Manduca sexta) lar- vae, that has hemocyte coagulation-provoking activity. The 72 kDa scolexin complex is composed of two 36 kDa subunits. To examine the protein secretory pathways in insect epithelia a polyclonal antibody was raised against the 36 kDa hemolymph protein. This MsH36 antibody recognised a 36 and a 72 kDa pro- tein in tissue homogenates. On the basis of the characteristic labelling pattern observed on immunoblots and immunocytochemical sections we concluded that the 36 kDa protein in the hemolymph, in the midgut and in the epidermis was identical with the scolexin subunit. In present paper we report a labelling shift in the midgut epithelium between goblet and columnar cells that may be controlled by the hormonal system. A 72 kDa protein showed similar epitops and molecular weight to the scolexin com- plex and was detected in epidermis and in cuticle under both reducing and non-reducing conditions. Tissue localization of 36 kDa and 72 kDa MsH36 antibody labelling proteins indicated the possibility that the epidermal cells produce two kinds of scolexin-like proteins. The complex composed of 36 kDa subunits are transported basolaterally into the circulation and display hemocyte coagulation inducing activity while the 72 kDa form contains two subunits linked covalently secreted apically into the cuticle.

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The unicellular ciliate, Tetrahymena has a complete hormonal system. It has receptors for receiving hormones, produces, stores and secretes hormones, similar to mammalian ones and has signal transduction pathways, for transmitting the information given by the hormones. The first encounter with a hormone provokes the hormonal imprinting under the effect of which the further encounters with the same hormone induces altered (usually enhanced) reaction (hormone binding, hormone synthesis, chemoattraction, movement, growth etc.). The effect of imprinting is durable, it can be observed also after 1000 generations, or after one year in non-dividing cells. Receptors of the nuclear envelope also can be imprinted. The plasma membrane receptors provoked by imprinting are similar to the receptors of mammals. Although steroid hormones are not present in Tetrahymena, the production of them and their receptors can be induced by imprinting. The hormonal imprinting is an epigenetic process and inhibition of DNA-methylation alters the imprinting. Hormonal imprinting in Tetrahymena was likely the first epigenetic phenomenon which was justified at cellular level. It is very useful for the unicells, as it helps to avoid dangerous molecules more easily or to find useful ones and by this contributes to the permanence of the population’s life.

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Kidney blood flow is highly regulated by a combination of myogenic autoregulation, multiple neurohormonal systems and the tubuloglomerular feedback system, the later of which specifically relates tubular reabsorption to the filtered load. Oxygen and substrate requirements of the kidney are dictated by both supply of oxygen and substrates and metabolic demands of the kidney. The tubuloglomerular feedback system utilizes mediators which are intimately linked to cellular metabolism, ATP and adenosine. This system based upon communication transfer between the macular densa and the afferent arteriole stabilizes kidney function and is not static but temporally adapts or resets to new external physiologic conditions. Such temporal adaptation occurs via modulators such as nitric oxide (NO), primarily derived from NOS-1, angiotensin II and COX-2 products. These hormonal influences also exert capacities to modulate cellular demands for oxygen, particularly NO which decreases oxygen consumption via multiple mechanisms. The several mechanisms whereby NO and other hormonal systems and transporter activity can regulate and produce changes in kidney metabolic demands are discussed. Modulators which influence temporal adaptation and resetting of TGF are also significant contributors to the regulation of cellular oxygen consumption in the kidney. These systems may act in concert to preserve the coordination of filtered load and tubular reabsorption and the metabolic demands of kidney function, thereby determining the ischemic threshold for kidney function.

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A krónikus szívelégtelenség magyarországi prevalenciája 1,6% a felnőtt populációban. Nyolcvanéves kor felett a prevalencia már 15–20%. A szívelégtelenség kezelésének alapja a neurohumorális blokád. Ennek részei az angiotenzinkonvertáló enzim gátlószere (intoleranciában az angiotenzinreceptor-blokkoló), a béta-receptor-blokkoló és a mineralokortikoidreceptor-antagonista gyógyszercsoportok. A béta-receptor-blokkolókat negatív inotrop hatásuk miatt sokáig mellőzték a szívelégtelenség kezeléséből. Az elmúlt évtizedek során végzett tanulmányok azonban szívelégtelenségben igazolták a béta-receptor-blokkolók mortalitást csökkentő hatását. A bisoprolol kedvező hatékonyságát szintén számos nagy tanulmány eredménye támasztja alá. Orv. Hetil., 2013, 154, 1731–1734.

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As the unicellular ciliate, Tetrahymena has insulin receptors and produces insulin itself, which can regulate its glucose metabolism and other cell functions, in the present experiments the feed-back, the effect of glucose on the insulin binding and insulin production was studied. The cells were kept partly in tryptone-yeast medium, partly in Losina salt solution. The duration of treatment (in 0.1, 1.0, 10.0 mg/ml glucose) in the binding study was 10 min, in the hormone production study 30 min. FITC-insulin binding was significantly decreased only by 0.1 mg/ml glucose treatment in medium and by 10 mg/ml glucose in salt. The insulin production was significantly lower only in cells treated with 10 mg/ml glucose in medium. The insulin binding in salt was always higher and the insulin production always lower, than in medium. Earlier results demonstrated that the hormonal system (presence of hormones, receptors and signal pathways) of higher ranked animals can be deduced to a unicellular level, however, the feed-back mechanism is not really present here, only the traces can be observed in these protozoa.

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A renin-angiotenzin rendszer szervezetünk egyik legjelentősebb hormonális rendszere, amelynek juxtaglomerularis apparátusban történő szabályozása és szerepe jól ismert. Jelen összefoglaló a vese embrionális fejlődésével párhuzamot állítva a gyűjtőcsatorna renintermelését írja le, valamint ennek lokális szerepét és terápiás célpontként szolgáló lehetőségeit igyekszik feltárni. Nemrégiben került leírásra, hogy krónikus angiotenzin-II-kezelés során, két vese-, egy klip modellben, illetve diabetes mellitusban a gyűjtőcsatorna jelenti az intrarenalis (pro)renintermelés legfőbb helyét. Ebben a lokalizációban a (pro)renin előtt út nyílhat az interstitialis renin-angoitenzin rendszer komponensek, a szisztémás keringés és a nemrégiben leírásra került (pro)reninreceptor felé. A (pro)renin saját receptorán keresztül intracelluláris profibroticus utakat képes aktiválni, így egyúttal potenciálisan új célpontja lehet a hypertoniához kapcsolódó vagy diabeteses nephropathia kezelésének, illetve eszköze a krónikus vesekárosodást előidéző folyamatok korai diagnosztizálásának. Orv. Hetil., 2013, 154, 643–649.

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