Objective To investigate the expression of endothelin-1 (ET-1 ), nitrogen monoxidium (NO), vascular endothelial growth factor (VEGF) and brain tissue VEGF induced by chronic intermittent hypoxia (CIH) in aged rats. Methods The CIH model of aged rat was established by using intermittent hypoxia. The levels of ET-1, NO and VEGF in the plasma were detected at 3, 6 and 9 weeks after experiment in each group. The expression of VEGF in brain tissues and the pathological changes of the vessels of the cerebra and the ratio between the thickness of vessel wall and external diameter (WT%) were observed. Results In CIH group, the ET-1 and VEGF levels increased, however NO level decreased. The levels of ET-1 and VEGF were higher at 3 weeks in CIH group than in UC group (t=2.47 and 2.38, both P<0.05), however NO level was lower in CIH group than in UC group (t=2.39, P<0.05). VEGF levels increased significantly at 9 weeks in CIH as compared with UC group [(171.1±13.5) pg/ml vs. (109.8±8.6) pg/ml, t = 3.46, P< 0.01]. The levels of VEGF in CIH group increased remarkably at 9 weeks as compared with 3 weeks [(129.3±12.3) pg/ml, t=2.38, P<0.053. VEGF levels in CIH group showed positive correlation with the time of intermittent hypoxia. The changes of cerebral vessels in UC group were not found, while the aged rats in CIH group showed cerebral neuron cells swelling and blood vessel hyperplasia. The WT% of cerebral small artery was more apparent in CIH group than in UC group at 3 weeks (t=2.34,P<0.05). The expression of VEGF in cerebra was higher in CIH group than in UC group in the three stages (r=2.37, P<0.05). There was an aggravated tendency in the change of the expression of brain tissue VEGF and WT% over time. The change was more apparent at 9 weeks than at 3 weeks (t=2.32 and 2.35, both P<0.05). Conclusions CIH can induce an increase in the expression of ET-1 and VEGF, a decrease in the expression of NO in aged rats. The over expression of VEGF and the disbalance of ET-1 and NO levels can cause brain cellular swelling, arteriola vessel wall thickening,lumens stenosis.

Lamiophlomis Herba， one of the medicinal herbs commonly used by the Tibetan ethnic minority， has the effect of activating blood， stopping bleeding， dispelling wind， and relieving pain and is frequently used to treat trauma， traumatic bleeding， rheumatic arthralgia， and dampness and dampness-heat. By a review of ancient Tibetan medicine classics， materia medica classics， and modern literature， this paper systematically analyzed the name， nature， taste， original plant， medicinal part， harvest， processing， efficacy， and indications of Lamiophlomis Herba. The textual research showed that Lamiophlomis Herba was first recorded in the Somaratsa （《月王药诊》） in the middle of the eighth century. This medicinal herb was mainly recorded with a plain and warm nature and a sweet， bitter， and astringent taste. The herb was recorded as non-toxic in other books except the Tibetan Medicinal Plants in Gannan of Qinghai-Tibet Plateau （《青藏高原甘南藏药植物志》）. In the books of the past dynasties， the aboveground part of Lomiophlomis rotatd was used as medicine. In addition， there were also records of using the whole herbs of Ajuga ovalifolia， A. ovalifolia var. calantha， and Oreosolen wattii as the medicine. In ancient times， the herb was mainly harvested before Frost's Descent in the 8^th-9^th months of the lunar calendar， while it was mainly harvested during the flowering-fruiting stage in autumn in modern times. Due to the decreased reserve of Lamiophlomis Herba， the medicinal part evolved from whole herb or fresh leaves to the aboveground part. According to the ancient and modern records， this herb mainly has the functions of nourishing bone and marrow， eliminating dampness and dampness-heat， stopping bleeding， and relieving pain. In ancient times， it was used for treating parasitic diseases， menostaxis， spermatorrhea， diarrhea， and nourishing the body. This paper aims to provide a basis for further development and study of Lamiophlomis Herba through the textual research.