1987 Fiscal Year Final Research Report Summary
Endocrine control of serum Ca, Na and K in lower vertebrates and its evolution
| Project/Area Number |
60440006
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物形態・分類学
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| Research Institution | Toyama University |
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Principal Investigator |
OGURO Chitaru Professor; Faculty of Science, Toyama University, 理学部, 教授 (40018974)
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| Co-Investigator(Kenkyū-buntansha) |
SASAYAMA Yuichi Associate Prof., Faculty of Science, Toyama University, 理学部, 助教授 (30018999)
UCHIYAMA Minoru Associate Prof.; Nippon Dental University (50095072)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Serum mineral control / Endocrine control / Serum calcium / Serum sodium / 血清Ca |
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| Research Abstract |
The present project was held on the basic ideas shown below. (1) Check species as many as possible since very small number of species have been subjected in this field of research in lower vertebrates. (2) Control mechanism of serum Ca, Na and K should be studied comprehensively and not be considered sepatetely. (3) Ionic Ca in serum should be treated differently from bound Ca.
The results obtained: (1) The ratio of serum ionized Ca (iCa) to total Ca (tCa) is quite different between groups and even species in a group as shown in an example; Uranoscopus japonicus iCa/tCax100=53.3%, Gnathagnus elongatus iCa/tCax100=65.3%. These 2 species are belonging to the same family. Thus, it should be careful to apply a conclusion from one species to the other species. Furthermore, the iCa/tCa ratios are smaller in teleosts than in elasmobranchs. This may show an increase occurred in Ca binding protein in serum during the evolution from lower piscie forms to higher ones.
(2) In the present project, 4 species of elasmobranchs, 27 species of teleosts,4 species of urodelan amphibians, 7 species of anuran amphibians and 5 species of reptiles were studied. Through the comparative studies in these animals, it was shown that the endocrine control of serum mineral concentrations have evolved from a comprehensive by the pituitary gland to more specific by individual endocrine gland. For an instance, hypercalcemic control is performed by the pituitary gland in piscine forms but it is done by the parathyroid gland in higher forms. Furthermore, there are an intermediate form between these extremities. Urodelan amphibians, especially lower species, are typical representative.
(3) It was suggested that serum Ca and Na concentrations are not controlled independently but with some intimate relationship.
The results noted above made a enough foundation for the study in this field.
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Research Products
(11 results)
