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Station de Recherches Avicoles (Institut National de la Recherche Agronomique), Centre de Recherches de Tours, 37380 Nouzilly, France; and * Unité de Recherches de Diabétologie et d'Etudes Radioimmunologiques des Hormones Protéiques, U. 55 (Institut National de la Santé et de la Recherche Médicale), Hôpital Saint Antoine, 75012 Paris, France
The effects of training to various rhythms of intermittent total starvation (ITS) or intermittent protein starvation (IPS) on the plasma glucose and the plasma insulin levels were studied in the growing chicken. Both types of feeding improved the glucose tolerance in spite of a decrease in the insulin response. After an oral glucose load, plasma free fatty acids showed opposite variations to plasma insulin and plasma glucose. The insulin released in response to a test meal was unchanged. In the ITS 1-1 group (1 day fasting-1 day feeding cycles), low glycemia-low insulinemia were observed during the fasting period of the cycle and high glycemia-hyperinsulinemia during the repletion period in response to the "adaptive hyperphagia." In the IPS 1-1 group (1 day feeding with the protein free diet-1 day feeding with the balanced diet cycles), glycemia was sustained at a high level during both periods of the cycle and insulinemia was depressed by feeding with the protein-free diet and highly stimulated by refeeding with the balanced diet. Therefore, in the chicken, intermittent feeding increases the insulin sensitivity of target tissues and modifies the B-cell sensitivity to glucose. The highest decrease in B-cell sensitivity to glucose was obtained with the protein free diet which further emphasizes the glucose-amino acid synergism previously observed for insulin release.
KEY WORDS: chicken periodicity of eating protein glucose tolerance insulin insulin sensitivity insulin release
Manuscript received 29 August 1978.