Chronopharmacology of antihypertensive drugs.

Research Project

Project/Area Number	60480474
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	応用薬理学・医療系薬学
Research Institution	Medical College of Oita
Principal Investigator	EBIHARA Akio Department of Clinical pharmacology, Medical College of Oita, 医学部, 教授 (10048960)
Co-Investigator(Kenkyū-buntansha)	KOIKE Yuichi Department of Clinical pharmacology, Medical College of Oita, 医学部, 助手 (90109421) FUJIMURA Akio Department of Clinical pharmacology, Medical College of Oita, 医学部, 助手 (90156901)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1988)
Budget Amount *help	¥7,000,000 (Direct Cost: ¥7,000,000) Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1985: ¥6,500,000 (Direct Cost: ¥6,500,000)
Keywords	hypertension / chronopharmacology / circadian rhythm of blood pressure / atenolol / 24時間血圧測定 / 血圧日内変動 / β遮断薬
Research Abstract	It is well known that circadian rhythms is found in blood pressure fluctuation within a day. To study the circadian rhythm of blood pressure in hypertensive patients and in normotensive subjects, we used the novel method that can face the problem of the distribution of blood pressure, Power-Normal Transformation model (PNT model). Fiftyty three hypertensive subjects and 18 normotensive subjects were examined. Blood pressure was measured non-invasively by automated cuff inflating device (ICR 5200 Ambulatory Blood Pressure Recorder) with 15 minutes' interval for 24 hours. Seven hypertensive patients were examined repeatedly before and after the treatment of atenolol, a beta adrenergic receptor antagonist, once a day for 2 months. In normotensive subjects, rhythms of blood pressure with significant amplitudes were found in 17 subjects out of 18 and their acrophase were found in the afternoon. In hypertensive patients, the same rhythms as those found in normotensive subjects; acrophase in the afternoon, were found in about 60 % of the patients, and 20 % of the patients had no significant rhythms in their blood pressure. The rest 20 % patients has significant rhythms, but the acrophases of the rhythms were found in the evening and in the morning. There was a tendency that the patient with longer history of hypertension has the different rhythm from that found in normotensive subjects. Atenolol modified the rhythm of blood pressure in 4 partients out of 7 after 2 months' chronic therapy, so 2 patients were reexamined after 4 months, and the rhythms were similar to the rhythms that were found before the atenolol therapy. It is concluded that there are some kinds of blood pressure rhythms in hypertensive patients, and that the rhythm can be modified by the history of hypertension and by the administration of drugs.