Platelet Serotonin Transporter Function and Heart Rate Variability in Patients with Panic Disorder

Many studies showed abnormal serotonin transporter (5-HTT) function and heart rate variability (HRV) in panic disorder patients. The present study investigated the relationship between HRV power spectral analysis findings and platelet serotonin uptake in panic disorder patients. Short-term HRV over 5 min and platelet serotonin transporter uptake parameters (V(max) and K(m)) were measured both in 45 patients with panic disorder and in 30 age-matched normal healthy control subjects. Low frequency power (LF) normalized unit (nu) and LF/high frequency power (HF) were significantly higher, whereas HF and HF nu were lower in the patient group than in the control group. V(max) and K(m) were all significantly lower (i.e., reflects decreased 5-HTT function) in patients with panic disorder than in normal controls. In the patient group, Km was negatively correlated with LF/HF and LF nu whereas no such correlations between them were found in the control group. By multivariate analysis based on multiple hierarchical linear regression, a low Km independently predicted an increased LF nu even after controlling for age, sex, and body mass index in the patient group. These results suggest that impaired 5-HTT function is closely related to dysregulation of autonomic nervous system in panic disorder.

Platelet serotonin in headache patients treated by new trend acupuncture.

Headache can be treated with acupuncture but its mechanism is virtually unknown. Since serotonin is considered to be an important factor as well as hyperactive platelets in the causation of migraine headache, a before and after study design was employed to evaluate the effects of acupuncture on the platelet serotonin and platelet aggregation in headache patients. Thirty-three patients, 18 suffering migraine headaches and 15 tension headaches were treated with dry needle acupuncture accompanying breathing exercise. Platelet serotonin was measured by spectrophotofluorometric method before and after treatment and found to be increased in 25 patients and decreased in 8 patients. The former groups show a statistically significant increase of p<0.01 (mean difference 0.15 + 0.26). Platelet aggregation induced by aggregating agents was also calibrated as to maximum response. The aggregations induced by collagen 1 ug, ADP 3 Um, adrenaline 1 or 25 uM, were decreased after acupuncture with significant collagen-induced aggregation (p<0.05). This suggests platelet serotonin and aggregation play a significant role in the treatment of headache by both inhibiting aggregation and by serotonin release. Thus the platelet serotonin is increased. Some interesting pints have been discussed in this report.