Influence of short-term starvation on blood elements : possible relation to metabolic changes

Abstract EN

Background: Starvation is known to disturb the body hormonal balance.

Total fast or pure water diet is recommended by several authors for treatment of obesity due to hyperphagia.

Despite the wealth of literature on the hormonal and metabolic disturbances of starvation, little attention has been made to the effect of total fasting on the different blood elements.

Aim of the study: The aim of this work was to study the hematological effects of short-term starvation in rats with special concern on platelet functions, and to relate the observed effects to some of the metabolic consequences of starvation, namely blood glucose, albumin and potassium levels.

Also, the role of changes in plasma oxidative stress marker malondialdehyde (MDA) was investigated.

Materials and Methods : Two groups of Wistar rats were used.

Group I: control group that was allowed food and water ad libitum to the time of experiment.

Group II : rats were totally fasted for 6 days and allowed water only ad libitum.

On the day of the experiment, animals were weighed, the body mass indices were calculated and blood samples were collected for assessment of complete blood picture.

Erythrocyte count (RBCs), hemoglobin content (Hb), packed cell volume (PCV), erythrocyte indices, total and differential leucocytic counts as well as platelet count and platelet indices were determined.

Platelet aggregation was assessed in the separated platelet rich plasma using ADP as an aggregating agent.

Heparinized samples were subjected to biochemical determination of blood glucose, albumin, potassium and malondialdehyde levels.

Results: 6-day starved rats showed significant decreases in blood levels of glucose, potassium and the oxidative stress marker MDA.

Plasma albumin was insignificantly decreased.

These effects were associated with significant decreases in body weights and body mass indices.

Hematologic effects: 6-day starved rats displayed significant rises in RBCs number, Hb content and PCV values.

The erythrocyte indices were not significantly changed from control rats.

Total number of white blood cells was significantly reduced.

This leucopenic response was accompanied with similar, though insignificant, decreases in the % of lymphocytes, monocytes and basophils.

Total food deprivation for 6 days in rats significantly depressed the platelet count, platelet indices, while platelet aggregation, induced in vitro by ADP, was significantly enhanced.

Conclusions: In addition to inflicting metabolic disturbances in the form of hypoglycemia and hypokalemia, short-term starvation for 6 days also contributes to hematological changes, namely polycythemia, leucopenia, thrombocytopenia and enhanced platelet aggregation.

The relationships between such hematological alterations and the metabolic response to starvation are described.

The role of apoptosis in the observed leucopenia and the mechanisms of increased platelet aggregability are also discussed.