Serotonin-induced platelet intracellular Ca2+ response in patients with anorexia nervosa

Serotonin (5-HT) is involved in the regulation of food intake. In anorexia nervosa there is a disturbance in 5-HT function. The stimulation of 5-HT(2)-receptors in platelets is a useful peripheral model to investigate the cascade of signal transduction and neuronal functioning.

25 anorexic female patients between the ages of 11 and 18 years with a mean body mass index (BMI) of 13.9+/-1.3 kg/m(2) participated in this study. The 21 healthy female controls revealed a mean BMI of 20.5+/-2.7 kg/m(2). 5-HT stimulated intracellular Ca(2+) response of the platelets was obtained using the Fura-2 method at the time of admission, during therapy and when the target BMI was reached.

We found a significant (p<0.01) decrease in 5-HT-induced Delta[Ca(2+)](i) at admission and a significant (p<0.05) increase of Delta[Ca(2+)](i) during treatment in patients with anorexia nervosa. Anorexic patients with and without comorbid depression had a comparable Ca(2+) release. However, low and high Ca(2+) responders showed a different course of Delta[Ca(2+)](i). The treatment with antidepressants led to a significant increase of Delta[Ca(2+)](i) in those patients with concomitant depression.

Since the course of Delta[Ca(2+)](i) is not related to BMI or the presence of comorbid depression, we conclude that serotonergic transmission or signaling pathways could be disturbed in patients suffering from anorexia nervosa. One inference of this preliminary study is that administration of antidepressants may be more effective in patients with concomitant depression.