The Possibility of the Amplification of Hormone Receptors in Early Periods of Differentiation

Analysis of the Progress of Hormone-Receptor Amplification during Differentiation in Regenerating Planarians

“…For example, the phagocytic reaction of Tetrahymena evoked by histamine treatment proved to be consistently stronger over a long period as the result of a histamine pretreatment Lantos, 1973, 1975). In another experiment we have found that a short epinephrine treatment of regenerating planarians caused, in the fully regenerated animals, an increased sugar uptake evoked by a second epi nephrine stimulus (Csaba and Kadar, 1978). In this experiment, the treatment for 3 days, from the beginning o f the regeneration, has led to the same effect as a consecutive treatment o f 28 days.…”

Development and Persistence of Receptor ‘Memory’ in a Unicellular Model System

“…If the cell membrane structures capable of acting as receptor exist without simultaneous presence of the adequate signal molecule (hormone), as is the case at the lower levels of phylogenesis, the first interaction initiates the development of the hormone receptor system as such, and reinforces it via selection or amplification [2,3). If the receptor function of a given cellular structure is genetically de termined, the first -usually perinatal -expo sure to the hormone accounts for establish ment of the normal receptor-hormone rela tionship [4], On reexposure, cellular response to the hormone will be up to 50% greater [1,4,5] than initially. Regardless whether the cell originally involved in imprinting had been a unicellular entity or part of a higher (mammalian) organism, the increased re sponsiveness is clearly associated with a progeny generation.…”

Experimental Study of Hormone Receptor Development in a Unicellular Model System

“…The mechanism of hormonal imprinting seems to operate at both the phylogenetic and the ontogenetic level of receptor develop- ment. However, while during phylogenesis the first encounter with the hormone -if advantageous for the cell or the organism of which the cell is part -operates both via selection and amplification in equal degree [Csaba and Lantos, 1977;Csaba et al, 1981], in ontogenesis it is amplification, i.e., the reinforcement of the already existing receptor structures [Csaba and Nagy, 1976;Csaba and Kadar, 1978;Csaba el al., 1980] which seems to be the primary mechanism. Whichever mechanism is considered, the mode of trans mission to daughter cells of the responsive ness elicited by the single original impulse is still obscure, although unequivocal evidence was presented that the effect of the original hormonal imprinting does reappear in sev eral progeny generations.…”