Search

Glycogen reserves are entirely consumed during total starvation of Bombyx mori L. larvae. While the storage of glycogen is lowering and the dietary supply of carbohydrates stopped, the amount of trehalose also decreases but less rapidly than this of glycogen. Relative homeostasis is maintained but only for the ten first hours of inanition. Quantitative evaluation of blood trehalose, which is preformed more rapidly than glycogen analysis, might be used as an efficient test to characterized some physiopathological states.

The haemolymph levels of trehalose, glucose and fructose in foraging worker bees, have been compared in 4 different colonies of each of the following races: mellifica (M), ligustica (L), caucasica (C) and their hybrids. Significant differences were found between races, with increasing values in the order: L leads to M leads to C leads to (L X C) X M; in the extreme cases, the amplitude of those differences reached a 1 to 4 range for glucose and 1 to 5 for fructose. The trehalose levels showed lower variations and did not follow the heterosis effect observed in hybrids.

Administration of trehalose by parenteral route to mammals (Guinea-pig and rabbit) equipped with Kidney trehalase is followed by rapid hydrolysis of the disaccharide which is excreted in urine only in very low amounts. When the animal under investigation has not trehalase in the kidney (rat), practically the total amount of trehalase is excreted in urine. Perfusion of kidney in rabbit confirms the very rapid hydrolysis of trehalose by this organ.

Changing the qualitative and quantitative level of diet may affect the physiology of the insects. However only the total growth of the larvae is generally pointed out. Biochemical changes in undernourished larvae have been rarely investigated. For this purpose Bombyx mori larvae reared upon Spring leaves are compared to larvae reared upon Autumn leaves (poor nutritional value because of their Chemical composition). In both cases the analyses were carried out from the fourth larval ecdysis to the beginning of spinning. Three measurements indicate the development of larvae growth:--the mean weight of the larvae;--the fresh and dry weight of fat body;--the hemolymph volume.