AIM: To investigate the effect of L-phenyla lanine on vascular remodeling in hypertensive rats. METHODS: Vascular remodeling was measured by laser scanning conf ocal microscopy (LSCM) in mesenteric resistance arteries isolated from spontaneo usly hypertensive rat (SHR) and normotensive Wistar-Kyoto (WKY) rat. The effect of L-phenylalanine on the hypertensive vascular remodeling was observed. The thi rd most distal first-order branches of mesenteric resistance arteries from SHR a nd WKY were studied. The arteries were fixed under pressure. The segments were s tained with the nuclear dye propidium iodide. The diameter, wall thickness and o rientation angle of smooth muscle cells were measured with LSCM. RESULTS: Compared with WKY, SHR arteries showed: (1) smaller lum en, (2) increased wall thickness, (3) disorganized orientation angle of smooth m uscle cells. L-phenylalanine treatment induced specific changes in the lumen, wa ll thickness and the orientation angle of smooth muscle cells. CONCLUSIONS: Hypertension induces vascular remodeling of the bra nches of mesenteric arteries from SHR. L-phenylalanine inhibits the vascular rem odeling process of hypertension.

BACKGROUND: During vascular dementia, ischemia, hypoxia, energy expenditure, abnormal metabolism of neurons, decrease of generation of Adenosine Triphosphate and disorder of ionic environment in and out of cells are observed in brain tissue, which can cause abnormal release of monoamine transmitter.OBJECTIVE: To probe into effect of shenma yizhi capsule on content of monoamine transmitter in brain tissue of rat models with vascular dementia induced by multiple cerebral infarction.DESIGN: Randomized controlled study.SETTING: Pathological and Physiological Department o Liaoning Basic Medical Institute.MATERIALS: Totally 96 Wistar rats of either gender,aged 8-12 months, weighing 270-500 g, were selected. METHODS: The experiment was completed in the Pathological and Physiological Department of Vocational-technical College, Liaoning College of Traditional Chinese Medicine from April to July 2001. All rats of either gender were divided into 6 groups with 16 in each group. Wistar rats in 5 groups were injected with cruor embolus in internal carotid artery to make animal model of vascular dementia induced by multiple cerebral infarction.After modeling, rats were randomly divided into 3.2 g/kg, 1.6 g/kg and 0.8 g/kg shenma yizhi capsule groups (shenma yizhi capsule was extracted from ginseng and tall gastrodia tuber with 2.7 g raw materials and provide by Xiyuan Hospital of Chinese Academy of Traditional Chinese Medicine),positive control group and dementia control group. Animals without modeling were regarded as normal control group. Rats in each dosage group were perfused with the corresponding dosage of shenma yizhi capsule; rats in positive control group were perfused with 1 mg/kg hydergine dihydroergotoxine; rats in dementia control group and normal control group were perfused with the same volume of saline solution. One week after modeling, rats were medicated once a day for 6 weeks. Content of monoamine transmitter was measured with high performance liquid chromatograpy.MAIN OUTCOME MEASURES: Content of monoamine transmitter such as levarterenol, adnephrin, dopamine, indoleacetic acid, homovanillic acid and 5-serotonin.RESULTS: Nine rats died because of self-body quality and environmental change, and totally 87 animals entered the final analysis. Content of levarterenol of rats in dementia control group was lower than that in normal control group [(0.40±0.23), (0.70±0.14) ng/g, t=2.712, P ＜ 0.01]; content of levarterenol of rats of 3.2 and 1.6 g/kg dosage groups was higher than that of dementia control group [(0.57±0.09), (0.58±0.19), (0.40±0.23) ng/g,t=2.211, P ＜ 0.05], but was lower than that of normal control group. Content of levarterenol of rats of 0.8 g/kg dosage group was lower than that of normal control group [(0.48±0.23) ng/g, t=2.213, P ＜ 0.05], but was higher than that of dementia control group and positive control group [(0.41 ±0.19) ng/g]. Differences of other neurotransmitters were not significant.CONCLUSION: Content of levarterenol in brain tissue of rats of dementia control group is decreased obviously, but shenma yizhi capsule can increase content of levarterenol in brain tissue of rats. The mechanism of shenma yizhi capsule on treating vascular dementia is possibly related with increasing content of levarterenol in brain tissue.