Patients with panic attacks had significantly higher platelet serotonin uptake compared to controls (Vmax 65 vs 47 pmol/10^8 platelets/min; p<0.05), while platelet serotonin levels were normal.
Case-Control (n=32)
Are platelet serotonin uptake and concentrations altered in patients with panic attacks compared to controls?
Patients with panic attacks exhibit increased platelet serotonin uptake but normal platelet serotonin levels, suggesting altered serotonergic function.
Absolute Event Rate: 65% vs 47%
p-value: p=<0.05
Platelet serotonin uptake and platelet serotonin concentrations were measured in 17 patients (5 males, 12 females) with panic attacks and 15 controls (8 males, 7 females). Higher Vmax values were found in the patient group compared with controls (65 +/- 7 vs. 47 +/- 3 pmol/10(8) platelets/min; p less than 0.05) while the affinity constant Km was not significantly different (0.6 +/- 0.1 vs. 0.5 +/- 0.1 microM). Platelet serotonin concentrations were not significantly different between the two groups (38 +/- 4 vs. 41 +/- 4 ng/10(8) platelets). These results confirm our earlier finding of increased serotonin uptake in patients with panic attacks and suggest that platelet serotonin levels are normal.
McIntyre et al. (1989) conducted a case-control in Panic Disorder (n=32). Panic disorder vs. Healthy controls was evaluated on Platelet serotonin uptake (Vmax) (p=<0.05). Patients with panic attacks had significantly higher platelet serotonin uptake compared to controls (Vmax 65 vs 47 pmol/10^8 platelets/min; p<0.05), while platelet serotonin levels were normal.