| Project/Area Number |
06839004
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
海洋生物学
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| Research Institution | University of Tsukuba |
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Principal Investigator |
YOKOHAMA Yasutsugu Inst.Biological Sciences University of Tsukuba Prof., 生物科学系, 教授 (50015583)
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| Co-Investigator(Kenkyū-buntansha) |
KURAMOTO Taketeru Inst.Biological Sciences University of Tsukuba Assoc.Prof., 生物科学系, 助教授 (40015813)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Decapod crustacea / Lobsters / Metabolic rate / Respration / Body temperature / Secretory organ / Serotonin / Octopamine / 甲殻類 / 呼吸量 / 代謝 / 体温 / 囲心腔ホルモン |
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| Research Abstract |
Using Japanese and American lobsters (Panulirusjaponicus and Homarus americanus), the respiration-temperature relationship (R-T curve) was investigated in vivo. The respiration (metaboric) rate was measured with two devices of a differential gas-volumeter and a platinum oxygen electrode. The metaboric rate of P.japonicus was increased with a decrease in temperature in a range of 13-20ﾟC and that of H.americanus also did in a range of 5-13ﾟC.P.japonicus lives in a zone of warm current while H.americanus in a zone of cold current. Therefore, the characteristics of R-T curve of these lobsters may be related to the temperature range of their habitat.
When serotonin (a component of the pericardial neurosecretorv hormones) was applied to the isolated heart and abdominal tonic muscle of P.japonicus, their respiration (metaboric) rate increased markedly. This suggests that the metaboric rate of muscle tissue could be increased against decreasing in body temperature if serotonin would be present in vivo. The other pericardial hormones, octopanine and proctolin, slightly raised rispiration rate of the skeletal and cardiac muscles but markedly increased excitability of the muscle membrane. If either octopanine or proctolin would be present in vivo, therefore, strength of excitation-contraction coupling of the muscle fibers could be maintained against a fall in body temperature although efficiency of the coupling would lower with decreasing temperature. Kuramoto and Tani (1994) demonstrated that the pericardial organs of P.japonicus release serotonin and octopmine with decreasing temperature from 20 to 13-15ﾟC.Therefore, both metabolic rate and membrane excitability of lobster muscle fibers in vivo could be enhanced by the pericardial hormones secreted with a decrease in body temperature.
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