Phosphagen and Protozoa
نویسندگان
چکیده
THE comparative investigations of Eggleton and Eggletonw, Meyerhof and Lohmanndi), Meyerhof (io), and Needham, Needham, Baldwin and Yudkin (n) have established a considerable body of information concerning the distribution of the phosphagens in the animal kingdom, and the character and implications of this knowledge have recently been analysed by Needham and Needham (13). But from all discussions hitherto, any mention of the Protozoa has been absent. This gap in our knowledge is unfortunate for two reasons, firstly because from a phylogenetic point of view it would be very desirable to ascertain the lower limit of distribution of such important compounds, and secondly because the Protozoa, or at least certain examples of them, would afford an interesting test of any possible association between phosphagen metabolism and ciliary, as well as muscular movement. With regard to the first of these reasons, the Coelenterates yielded interesting results in the work of Needham, Needham, Baldwin and Yudkin (13), for whereas a Ctenophore, PleurobracMa pileus, contained considerable amounts of arginine phosphate (43 per cent, of the free and labile water-soluble phosphorus), none was discoverable in the Actinozoa, Anihea rustica and cereus. Further work on the phosphagen of the Coelenterates would be very useful, but it is perhaps significant in this connection that Kutscher and Ackermannfo), though able to isolate free arginine from many marine invertebrates, could only obtain guanidine and agmatine from Geodiagigas. The question whether phosphagen was to be found elsewhere than in the Metazoa clearly merited examination. And with regard to the second of the reasons given above, some indications were found by Needham, Needham, Baldwin and Yudkin (i») that phosphagen might occur in situations primarily characterised by ciliary activity, e.g. the swimming gastrulae and plutei of echinoids.
منابع مشابه
On Phosphorus Metabolism in Embryonic Life Iii. Phosphagen in Avian Development By
INTRODUCTION. THE first paper of this series d») was concerned with the general outlines of the phosphorus metabolism of a number of invertebrate eggs during their development, while the second (14) dealt with the more specialised question of the phosphagen metabolism of the developing cephalopod egg. The embryo of Sepia offidnaHt was found to contain phosphagen at all stages of its development...
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Phosphagens are phosphorylated guanidine compounds which, via the catalytic action of corresponding phosphagen kinases, function as temporal and possibly spatial ATP buffers (Meyer et al. 1985) in cells capable of dramatic metabolic transitions such as muscle, neurons and spermatozoa. At least eight different phosphagen kinases have been identified and these enzymes are widely distributed throu...
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