- 著者
- AKIHITO OZAWA TETSU JOHKE KOICHI HODATE
- 出版者
- The Japan Endocrine Society
- 雑誌
- Endocrine Journal (ISSN:09188959)
- 巻号頁・発行日
- vol.41, no.6, pp.725-730, 1994 (Released:2011-01-25)
- 参考文献数
- 12
- 被引用文献数
- 3 4
Information about the plasma IGF-I concentrations in domestic animals in a cold environment is still limited. And mechanisms to change plasma IGF-I concentrations in cold environments are not fully elucidated. In this study, plasma insulin-like growth factor-I (IGF-I) in relation to plasma growth hormone (GH) and metabolite concentrations was investigated in pigs living at 20°C and at 4°C. Six pigs (Landrase breed; barrows, 118 days old, 51.0±3.5 kg body weight) were maintained for 2 weeks at 20°C in a climatic room. Then a placebo or recombinant bovine GH (100μg/kg body weight) was injected subcutaneously. Blood samples were taken through a catheter at -2, 0, 1, 2, 3, 4, 5, 6, 9, 12, 22, and 24 h after the injections. The same experiments were conducted on days 5 and 6 after the room temperature was changed to 4°C. Mean (±SD) basal plasma GH concentrations in pigs without bovine GH administration living at 20°C and at 4°C were 4.8±1.7 ng/ml and 4.6±2.8ng/ml, respectively. There were no significant differences between GH concentrations. On the other hand, the mean plasma IGF-I concentrations were 80.8±25.1ng/ml and 57.3±14.3ng/ml respectively. Plasma IGF-I concentrations in pigs living at 4°C were significantly lower than in pigs living at 20°C (P<0.05). Plasma glucose and non-esterified fatty acid (NEFA) concentrations in pigs at 4°C were significantly higher than in pigs at 20°C (P<0.05). Blood urea nitrogen (BUN) concentrations in pigs at 4°C were also higher than in pigs at 20°C. In an experiment on GH administration, the plasma GH concentrations in pigs at both 20°C and 4°C were increased to the peak (49.1±2.5ng/ml and 43.0±23.6 ng/ml, respectively) 2h after the GH injection. They then gradually decreased to the basal level within 22 h. Plasma IGF-I concentrations were significantly increased 3 or 4h after the GH injection, and they reached to the maximum 9 or 12h after GH injection. No statistical significance was observed in the increase in the plasma IGF-I concentrations between pigs living at 20°C and at 4°C after GH injection. These results indicate that basal plasma IGF-I concentrations in pigs living at 4°C were lower than at 20°C. And the increase in the plasma IGF-I after the bovine GH injection were not different at the two environmental temperatures.