Effect mechanism of α-adrenoceptor on sepsis-induced acute respiratory distress syndrome / 中华危重病急救医学

Acute respiratory distress syndrome (ARDS), characterized by acute hypoxic respiratory dysfunction or failure, is a manifestation of multiple organ failure (MOF) in the lung, which often caused by various non-cardiac reasons, included severe trauma, infection, shock; and the most common risk factor is sepsis which would cause uncontrolled host response to infecting factors. As a strong stressor during sepsis, the severe infectious state of the body triggers serious stress reaction. The hypothalamus-pituitary-adrenal cortical (HPA) axis and sympathetic-adrenal medulla axis were activated and participated the initiation and progression of the stress response through the production of adrenocorticotropic hormone (ACTH), glucocorticoid (GC), epinephrine and norepinephrine (NE). As the main hormones during sepsis, catecholamines (CA), including epinephrine and NE, could bind to adrenergic receptor (AR). After the binding, CA could play its role through the complicated signal way. Therefore, to explore the signal transduction pathway of α-AR, during sepsis, is important for revealing the mechanism of sepsis-induced ARDS.

Alpha-adrenergic receptor blocking effect of Cleistanthus collinus (Roxb.) Benth. and Hook f. leaf extract on guinea pig isolated smooth muscle preparations.

Aqueous extract of C. collinus leaves inhibited norepinephrine induced contraction in guinea pig vas deferens and aortic strip in a dose-dependent manner. Inhibition of acetylcholine induced contraction in ileum was dose independent. C. collinus extract per se had no effect on isolated guinea pig vas deferens and aortic strip, but inhibited norepinephrine induced contraction in a dose-dependent manner probably by its antagonist action on α-adrenergic receptor. It had inconsistent effect on guinea pig ileum in vitro preparation.

The Effects and Mechanism of Acupuncture on Post-Hemiplegic Shoulder-Hand Syndrome / 日本温泉気候物理医学会雑誌

To clarify the effects of acupuncture treatment on acute and chronic shoulder-hand syndrome, 20 minutes of manual acupuncture was applied to 14 patients with posthemiplegic shoulder-hand syndrome at the hemiplegic arm and hand (eight points of keiketsu) twice a week for 5 weeks.<br>Thermographic and laser doppler measurements showed the increases in skin temperature and blood flow of the affected hand. Although manual acupuncture produced long-lasting increases in skin temperature and blood flow of both hands, its effects were inhibited when 10-mg alpha-blocker phentolamine was injected beforehand. After 5 weeks of the acupuncture therapy, the increased skin temperature and blood flow of the affected hand were gradually reduced to normal levels.<br>Subjective and objective symptoms such as pain, local heating, and swelling showed positive improvement in 10 out of 14 patients after the 5 weeks of acupuncture therapy.<br>These results may suggest that the shulder-hand syndrome is produced by unknown sympathetic vasodilating mechanisms and that acupuncture plays a therapeutic role through the suppression of increased sympathetic tone.

Polyvanadate acts at the level of plasma membranes through aadrenergic receptor and affects cellular calcium distribution and some oxidation activities.

The activities of calcium-stimulated respiration, calcium uptake, a-glycerophosphate dehydrogenase and rates of oxidation in state 3 and of H2O2 generation, were found to increase and that of pyruvate dehydrogenase decrease in mitochondria isolated from livers of rats administered intraperitoneally or perfused with polyvanadate. Phenoxybenzamine, an antagonist of a−adrenergic receptor, effectively prevented these changes. It was also found that perfusion of the liver with polyvanadate reproduced one of the best characterized events of a-adrenergic activation-stimulation of protein kinase C in plasma membrane accompanied by its decrease in cytosol. These experiments indicate for the first time the α-adrenergic mimetic action of polyvanadate.