ISSN:
1433-8491
Keywords:
Intracellular calcium
;
Affective disease
;
Platelets
;
Lymphocytes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Many studies have demonstrated pharmacologic similarities between platelet and brain 5-HT2 binding sites. Therefore it may be possible to use platelets as a model for the central serotonergic neuron. Accordingly, a previcus report (Kusumi et al. 1991b) about elevated [Ca2+]i after serotonin stimulation in platelets of depressed patients was interpreted as further evidence for enhanced serotonergic sensitivity in depression. However, a very recent study showed an enhanced thrombin-induced platelet Ca2+ response, rather suggesting abnormalities of intracellular Ca2+ regulation in affective disorders. In the present study we have determined 5-HT2-and thrombin-induced Ca2+ responses in platelets and additionally phytohemagglutin (PHA)-induced Ca2+ increase in lymphocytes of medicated depressed patients (8 mono- and 2 bipolar, HRSD〉17) and of ten sex- and age-matched controls. The results showed no significant difference in basal calcium levels between the two groups and no significant difference in the Ca2+ response to thrombin although the response was higher in the patients. The Ca2+ increase after serotonin stimulation in depressed patients was significantly (P〈0.05) higher than in healthy controls. By contrast, the Ca2+ response to PHA in lymphocytes was significantly decreased in the patients. Our data confirm elevated Ca2+ responses after 5-HT2 receptor activation even in medicated depressed patients. However, Ca2+ responses in lymphocytes were decreased. Together with the observations of an enhanced Ca2+ response in platelets after thrombin stimulation, we speculate that the findings rather suggest alterations of [Ca2]i regulation in depression than specific changes of serotonergic sensitivity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02191580
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