Further studies on the effects of adrenal steroids in the active transport of serotonin into rat platelets.
Male rats were treated with a fixed dose of aminoglutethimide (50 mg/kg s.c.) or with progressively increasing doses (50-100 mg/kg s.c.) for 3 days. Corticosterone levels were found to be decreased in the latter group. Platelet uptake of serotonin as well as the apparent Vmax were decreased, whereas the Km of uptake were increased when compared with that of the control group. Addition of ACTH (10 iu/dl) to control rat platelet and corticosterone (10-80 micrograms/dl) or triamcinolone (0.5-5.0 micrograms/dl) to adrenalectomized rat platelet suspension in vitro did not increase the serotonin uptake of the preparation. Administration of exogenous dexamethasone (0.05-0.2 mg/kg i.m.) or triamcinolone (0.05-5.0 mg/kg i.m.) to adrenalectomized rats, caused a dose related increase in active uptake of serotonin by the platelets. Deoxycorticosterone (0.1-1.0 mg/kg i.m.) did not have this effect. The time course of response to, and the maximum percentage increase in platelet serotonin uptake by, exogenous corticosteroids are related to their glucocorticoid potency. The possible role of glucocorticoids on platelet serotonin uptake process is discussed.
Lee
P H
PH
Chan
M Y
MY
D000315:Adrenalectomy; D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001792:Blood Platelets / Q000378:metabolism*; D003345:Corticosterone / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage; D005938:Glucocorticoids / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000097:blood*
D005938:Glucocorticoids; D012701:Serotonin; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone