Department of Cardiovascular

Stuff;

Professor	Ichiro Nishio M.D. PhD
Associated Professor	Takuzo Hano M.D. PhD
Assistant Professor	Kazushi Tuda M.D. PhD
	Akira Baba M.D. PhD
	Masanori Hamada M.D. PhD
Junior Lecturer	Keizo Kimura M.D. PhD
	Toshio Imanishi M.D. PhD
	Hisashi Sasajima M.D. PhD
	Takashi Kubo M.D.
Senior Resident	Hiroki Kitabata M.D.
	Shinnichi Booka M.D. PhD
Postgraduate Student	Masayo Ibata M.D.
(PhD course)	Shigeho Takarada M.D.
	Chizu Moriwaki M.D.
	Katsuyou Kobayashii M.D.
	Shin-tarou Kuki M.D.
	Yosiki Matsuo M.D.
	Masahiro Obana M.D.

History;

The cardiovascular division was established in 1973 by Professor Emeritus Yoshiaki Masuyama (1925-2001) and Professor Ichiro Nishio (1938- ) both invited from the university of Tokyo. Their early work in hypertensive research enjoyed global reputation which was inevitably reflected in the higher educational level at this university. Our previous experimental work in hypertension has mainly been based on pharmacological methods which were brought in by Dr. Masuyama, Dr. Nishio and Dr. Masato Kuchii. In clinical research, our experimental endeaver made a great progress in 1976 by using spontaneously hypertensive rats (SHR), which included a lot of perfusion studies on the mesenteric and the kidney arteries, cell-culture works and membrane fluidity works.

Present status;

1. The cardiovascular system and the sympathetic nervous system ;
   One of our present interests in a pathogenesis of hypertension is the sympathetic nervous system. We are measuring catecholamines released from the central nervous system, peripheral nervous ending and the adrenal glands in order to clarify the mechanism of hyper-adrenegic status in the development of hypertension, as well as to clarify what happens if we applied basic medicine such as calcium channel blockers, angiotensin converting enzyme inhibitors and angiotensin II receptor blockades. Our recent findings indicate that the angiotensin converting enzyme inhibitors, the angiotensin II receptor blockades, N-type calcium channel blockades inhibit sympathetic nervous activities, but the L-type calcium channel blockades do not. Clinically, we have a great interest in neurally mediated syncope and related orthostatic hypotension. Recent advances in nuclear imaging have enabled us to analyze functional aspects of cardiac nerve endings. We combined the nuclear imaging with head-up tilt test to find out clinical importance in the sympathetic nervous system to maintain blood pressure.

2. Vascular pathological aspect;
   Hyper-responsiveness of artery in hypertension is a very important theme in this field. We have found several abnormalities of intracellular calcium handling in the vascular smooth muscle and the endotherium in hypertensive animal models using both pharmacological technique and a direct measurement of intra-cellular calcium by Fura 2. The understanding in the pathology of atherosclerosis has recently made a drastic change after the development of molecular biology. Based on a hypothesis that apoptosis of vascular smooth muscle cells is an important initiator of plaque rupture of coronary artery, we are proceeding the experiments on the role of oxidized LDL in the development of apoptosis in the molecular level. Kidney is also a key organ in the pathogenesis of hypertension. We had findings that several peptides regulate the tone of afferent artery using the single nephron perfusion system of rabbits. Membrane fluidity of red blood cells is an important factor in vascular micro-circulation. In essential hypertension, membrane fluidity was reduced and estrogen normalized this abnormality through the increased NO synthesis.

3. Cardiac aspects and Clinical service;
   We have a series of clinical findings in hypertensive heart, which shows the impaired cardiac diastolic function. Using isolated cardiac muscle cell of rats we have dicoverd that the abnormality of calcium mobilization from intracellular calcium store are closely related with diastolic function. In heart failure, renin-angiotension system and endothelin play significant roles in the patho-physiological condition. We have shown that angiotensin II receptor blockade improves the abnormal baro-reflex function and the remodeling of heart in myocardial infarction model animal. We also have a great interest in neurally mediated syncope and related orthostatic hypotension. Recent advances in nuclear imaging enable us to analyze functional aspects of nerve endings of the heart. We combined the nuclear imaging with tilt-up test to find out clinical importance in the sympathetic nervous system to maintain blood pressure. We have carried out the clinical study using MRI to evaluate the stenosis of coronary artery and the perfusion and viability of cardiac muscles in the patients with ischemic heart disease. Our department has 39 inpatient beds in the ward and 5 beds in the cardiac care unit where almost every kind of clinical tests are available. In 2001, we performed 475 cases of coronary cardiography and 183 cases of PTCA. The average number of outpatients in our clinics exceeds is more than 120 per day.