Melatonin in the unicellular Tetrahymena pyriformis: effects of different lighting conditions

Abstract

Melatonin content in the cellular fraction and medium of Tetrahymena pyriformis GL cultures was measured at different time points of light and dark exposures. Tetrahymena produced, stored and secreted immunoreactive melatonin, which in displacement and HPLC studies, behaved like synthetic melatonin. There was not a continuous secretion of melatonin produced by the cells. In contrast to this, storage of melatonin was observed, which was more expressed in dark conditions. Prolonged light exposure suppressed melatonin production and secretion alike, however it did not block it completely.

Factorial designs: an efficient approach to choosing the main factors influencing growth and hydrolase production by Tetrahymena thermophila

“…Growth suppression by melatonin has been observed with Tetrahymena pyriformis [12]. However, in our results, melatonin had a small positive effect on maximal T. thermophila population formation.…”

“…Many of these hormones directly influence physiological processes [4,12]. While melatonin synthesis by Tetrahymena is decreased in the presence of light, Tetrahymena growth seems to be relatively insensitive to light levels [12]. To date, there have been no reports on the combined influence of hormones, light, and culture conditions on hydrolytic enzyme production by T. thermophila.…”

“…Unicellular organisms such as Tetrahymena produce metabolites that are functionally similar to mammalian hormones. Many of these hormones directly influence physiological processes [4,12]. While melatonin synthesis by Tetrahymena is decreased in the presence of light, Tetrahymena growth seems to be relatively insensitive to light levels [12].…”

Hormonal interactions in : Effect of hormones on levels of epidermal growth factor (EGF)

“…As demonstrated earlier, insulin, ACTH, gonadotropins, relaxin, endothelin, endorphin, interleukin-6, histamine, serotonin, melatonin, epidermal growth factor (EGF), etc. can be found in Tetrahymena (Ko¨hidai et al, 2000(Ko¨hidai et al, , 2002(Ko¨hidai et al, , 2003Lenard, 1992;LeRoith et al, 1980LeRoith et al, , 1982LeRoith et al, , 1983Csaba and Kova´cs, 2000a;Rodriguez et al, 2004). Hormonal imprinting (the first encounter with the given hormone) can enhance the binding capacity of target receptors as well as the production of the imprinter hormone (Csaba, 1985(Csaba, , 1994(Csaba, , 2000Christopher and Sundermann, 1992;Kova´cs, 1999, 2000a,b).…”

Biogenic amines at a low level of evolution: Production, functions and regulation in the unicellular Tetrahymena

“…tyrosin is transformed non-enzymatically in the medium to L-DOPA, this is incorporated by the cells and enzymatically transformed to dopamine [15]. Melatonin is also synthesized by the cells, which is infl uenced by the lighting conditions and previous encounter (hormonal imprinting) [16][17][18][19]. Hungarica 62, 2015 Enzymes and genes related to biogenic amines Adenylate cyclase and guanylate cyclase were found in Tetrahymena and their activity was infl uenced by biogenic amines [20][21][22].…”