Nonshivering thermogenesis in king penguin chicks. II. Effect of fasting
| العنوان: | Nonshivering thermogenesis in king penguin chicks. II. Effect of fasting |
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| المؤلفون: | A. Lanni, F. Cohen-Adad, Claude Duchamp, P. Brebion, Hervé Barré, Jean-Louis Rouanet, G. Berne |
| المصدر: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 261:R1446-R1454 |
| بيانات النشر: | American Physiological Society, 1991. |
| سنة النشر: | 1991 |
| مصطلحات موضوعية: | medicine.medical_specialty, Physiology, Cellular respiration, Acclimatization, Mitochondria, Liver, Mitochondrion, Birds, Electron Transport Complex IV, Gastrocnemius muscle, Oxygen Consumption, Physiology (medical), Internal medicine, Brown adipose tissue, Respiration, medicine, Animals, Cytochrome c oxidase, biology, Muscles, Proteins, Skeletal muscle, Fasting, Thermoregulation, Mitochondria, Muscle, Cold Temperature, Microscopy, Electron, medicine.anatomical_structure, Endocrinology, Adipose Tissue, Liver, biology.protein, Energy Metabolism, Body Temperature Regulation |
| الوصف: | The effect of fasting on the energy metabolism of skeletal muscle and liver was investigated in cold-acclimatized short-term fasting (STF) (3 wk) and naturally long-term fasting (LTF) (4-5 mo) king penguin chicks, both groups exhibiting nonshivering thermogenesis (NST). A comparison was made with nourished cold-acclimatized controls. In these chicks, no brown adipose tissue deposits could be found on electron-microscopic observations of fat deposits. Protein content and cytochrome oxidase (CO) activity of tissue homogenates were measured in liver and pectoralis and gastrocnemius muscles, as were protein content, CO activity, and respiration rates of mitochondria isolated from these organs. Fasting-induced protein loss affected the pectoralis more than the gastrocnemius muscle, thus preserving locomotor function. In STF chicks, specific mitochondrial protein content and specific tissue CO activity were preserved but total organ CO capacity was reduced by half in pectoralis and liver following the fall in organ mass. In LTF chicks, both specific and total CO activity were drastically reduced in muscles, whereas specific CO activity was preserved in liver. In these LTF chicks, muscle mitochondria showed an energized configuration associated with an increased area of inner membrane in gastrocnemius. A reduction of respiratory control ratio (RCR) was observed in subsarcolemmal muscle mitochondria of STF chicks, whereas intermyofibrillar and liver mitochondria kept high RCR values.(ABSTRACT TRUNCATED AT 250 WORDS) |
| تدمد: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.1991.261.6.r1446 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::086f4bd0ca4ac51a9bf7c40baa8cc7b0 https://doi.org/10.1152/ajpregu.1991.261.6.r1446 |
| رقم الانضمام: | edsair.doi.dedup.....086f4bd0ca4ac51a9bf7c40baa8cc7b0 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15221490 03636119 |
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| DOI: | 10.1152/ajpregu.1991.261.6.r1446 |