The flow properties of individual erythrocytes have been studied in glass micropipets 4 \x in internal diameter. The pressure gradient required to establish a standard oscillatory movement over a 130-/x path in a three-second time period was measured in paired studies comparing diabetic and control erythrocytes suspended in Ringer solution. The pressure requirement was regularly elevated for the diabetic erythrocytes, averaging 50 per cent greater than the controls. Studies of erythrocytes comparing alloxan-diabetic rats with control rats demonstrated a similar elevation in required pressure. Red cells from subjects with hereditary spherocytosis offered less flow resistance than diabetic cells, and red cells from rheumatoid arthritics required no pressure increment. When erythrocytes are ejected from a 4-/x micropipet they return quickly to a discoid shape using stored elastic energy. Slow motion photography revealed that diabetic erythrocytes restore their shape less rapidly than nondiabetic erythrocytes, indicating that their reduced deformability is due to an elevation of either intraerythrocyte or membrane viscosity rather than to increased resistance to bending. Diabetes is regularly associated with an increased intracellular hemoglobin Ale; it is possible that hemoglobin Ale could raise intraerythrocyte viscosity. The observed disturbance in flow properties of individual erythrocytes is subtle. It would affect the flow of blood, particularly through active muscle, and modify the pressure exerted by individual erythrocytes on the muscle capillary wall.DIABETES 27:895-901, September, 1978.

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Rates of protein synthesis in the whole body and tissues of Octopus vulgaris collected in September 1985 and 1986 from the Bay of Naples were measured following a flooding dose injection of 3H phenylalanine. There were stable phenylalanine free pool-specific radioactivities and linear incorporation of radiolabel into arm-tip protein from 10 to 30 rain after the injection. In starved individuals there were no significant differences between the fractional rates of protein synthesis of the following tissues: ventricle, brain, branchial heart, arm tip, gill, stomach, arm, renal appendage and mantle. The mean value (+SE) for all the tissues was 3.02_+ 0.17% d-1. In individuals fed varying amounts of crab, resulting in differing growth rates, there was a linear increase in fractional rates of whole-body protein synthesis with growth rate. A standard 148 g octopus growing at 3.0% d -1 synthesised 0.54 g of protein, with 0.43 g of this protein retained as growth. The proportion of the total protein synthesis which was retained as growth increased with increasing growth rate; at a maximum growth rate of 6% d -1, over 90% of the protein synthesised was retained as growth. The ventricle, arm tip, gill, arm and mantle also showed similar patterns of a linear increase in fractional rates of protein synthesis with increased growth rates. The RNA concentrations in the whole body and tissues increased with increasing growth rates, but the major change was an increase in the efficiency of translation. It is concluded that rapid growth rates in O. vulgaris are brought about by high rates of protein synthesis and high efficiencies of retention of synthesised protein and, therefore, little protein degradation.

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