Serotonin uptake and imipramine binding in rat platelets after chronic dexamethasone and amitriptyline treatment

Dexamethasone suppression test identifies a subset of elderly depressed patients with reduced platelet serotonin transport and resistance to imipramine inhibition of transport

“…Aging also produces an increased incidence of abnormal DSTs (Stangl et al, 1986;Sharma et al, 1988) an association that is even more pronounced in elderly depression (Ritchie et al, 1990b;Brodaty et al, 1991). The close interrelationship between glucocorticoid status and serotonergic function (Chan and Lee, 1985;Arora and Meltzer, 1986;Kitayama et al, 1988;Shimoda et al, 1988;Joëls and De Kloet, 1991;Pepin et al, 1992) suggests that HPA dysregulation may have a significant impact on the reactivity to tricyclic antidepressants and particularly the serotonin-specific reuptake inhibitors that have become the mainstay of depression therapy (Carroll et al, 1981;Aghajanian et al, 1993;Young, 1994). Central serotonergic pathways are, in turn, major contributors to HPA control (Stokes et al, 1987;Korte et al, 1991) and, again, this regulation is disrupted in depression (Koenig et al, 1987;Lesch et al, 1990;Maes et al, 1991).…”

Platelet monoamine uptake in depression—a primary or secondary phenomenon?

“…Chan and Lee (1985) have investigated the effects of chronic ACTH and dexamethasone treatment on groups of rats and have shown that both treatments resulted in decreased platelet 5HT uptake, with decreased Vmax values. Furthermore, dexamethasone potentiated the effects of amitriptyline, imipramine and desipramine as 5HT uptake inhibitors in vitro.…”

“…Until this is done, however, the implications of platelet uptake studies in the pathogenesis of endogenous depression must remain in considerable doubt. REFERENCES Chan, M. and Lee, P. H. K. (1985). Serotonin uptake and imipramine binding in rat platelet after chronic dexamethasone and amitriptyline treatment.…”

Platelet monoamine uptake in depression — primary or secondary phenomenon?

“…He cites recent pharmacological evidence to show that this maybe the case. Both ACTH, which stimulates cortisol release from the adrenal cortex, and the synthetic glucocorticoid dexamethasone cause a reduction in V,,, of platelet 5-HT uptake (Chan and Lee, 1985). In contrast adrenalectomy , which will reduce cortisol concentrations, rather than increasing V,,,, causes a reduction (Tukianen, 1981;Lee and Chan, 1984).…”