Serotonin and the heart

Serotonin is a naturally occurring vasoactive substance that has diverse cardio-physiological effects. These effects can be explained by the existence of serotonin receptor subtypes which mediate different biological actions. The vasoconstrictive actions of serotonin are mediated by 5-HT₂ serotonergic receptors, and serotonin also amplifies the release and activities of other vasoconstrictors, such as angiotensin and norepinephrine. Abnormalities in the serotonergic system may play an important role in the patho-physiology of multiple cardiovascular disease states such as systemic hypertension, primary pulmonary hypertension and peripheral vascular disease. Selective 5-HT₂ serotonergic receptor blockers have been developed which appear to be potent vasodilators with therapeutic potential in various cardiovascular disease states. The largest clinical experience has been collected with ketanserin, and other agents in this class are being investigated. Prolongation of the ECG QT interval with 5-HT₂ serotonergic receptor blockers may pose a potential risk with these treatments in some patients.     

Anorexia and the heart

The heart is not spared the ravages of anorexia nervosa. Studies have shown that left ventricular function and myocardial mass are reduced and heart rate, blood pressure, and oxygen consumption in response to exercise are significantly less than normal in these patients. Dr Moodie reports results of testing of these patients by other investigators and by researchers at his own institution. He recommends continued cardiac monitoring during follow-up to assess the short- and long-term effects of anorexia nervosa on cardiac performance.     

Testosterone and the heart

Several large scale studies in recent years have demonstrated increased cardiovascular mortality in men with low testosterone, especially those with existing cardiovascular disease and type 2 diabetes. In some patients the baseline measurement was a single total testosterone level, in others the association was seen only with free or bioavailable testosterone. These differences are most likely related to different characteristics of the cohorts studied in terms of age, obesity and presence of metabolic syndrome. Other smaller studies show consistent benefit from testosterone replacement in terms of reduced insulin resistance, HbA1c, total, LDL-cholesterol, triglycerides and inflammatory markers for CHD. There is clear evidence for a reduction in visceral and lean fat mass, improvement in sexual function, mood and symptom scores. Whilst most of these benefits are modest, the combined effect on these surrogate markers for cardiovascular risk is considerable and the improvement in well-being is likely to be welcomed by patients. There is early evidence from non-randomised studies that physiological testosterone replacement is extremely safe and may reduce cardiovascular mortality. The fact that few patients in potentially risk groups are being screened and treated is probably because of the wide range of specialities involved and the reluctance of one discipline to embrace and manage testosterone deficiency.     

Alcohol and the heart

Acute alcohol ingestion can lead to alterations of either mechanical function or electrophysiologic properties of the heart, whereas chronic consumption can lead to progressive cardiac dysfunction and congestive cardiomyopathy. On the other hand, alcohol appears to have a protective effect for coronary artery disease when consumed in low amounts, although prophylactic use of alcohol is not recommended.     

Serotonin and the heart

Serotonin is a naturally occurring vasoactive substance that has diverse cardiophysiological effects. These effects can be explained by the existence of serotonin receptor subtypes which mediate different biological actions. The vasoconstrictive actions of serotonin are mediated by 5-HT2 serotonergic receptors, and serotonin also amplifies the release and activities of other vasoconstrictors, such as angiotensin and norepinephrine. Abnormalities in the serotonergic system may play an important role in the pathophysiology of multiple cardiovascular disease states such as systemic hypertension, primary pulmonary hypertension and peripheral vascular disease. Selective 5-HT2 serotonergic receptor blockers have been developed which appear to be potent vasodilators with therapeutic potential in various cardiovascular disease states. The largest clinical experience has been collected with ketanserin, and other agents in this class are being investigated. Prolongation of the ECG QT interval with 5-HT2 serotonergic receptor blockers may pose a potential risk with these treatments in some patients.     

心脏瓣膜结构及其功能对心脏发育和心脏疾病的影响

发育成熟的心脏瓣膜是由一层内皮细胞包裹的高度有序的细胞外基质和瓣膜间质细胞组成。心脏瓣膜的细胞外基质根据对瓣叶和支撑结构的不同生物学性能可以分为三类:富弹性蛋白层、富粘蛋白层和富胶原蛋白层。信号转导通路在原始瓣膜形成及瓣膜结构功能的持续维持上起着至关重要的作用。动物模型为研究瓣膜发育及其相关疾病过程提供了很重要的支持。瓣膜疾病是一个具有重要意义的公共卫生健康问题,越来越多的证据显示畸形发育是其发病机制的一个基础。未来需要更多更深层次的研究来探索调节瓣膜发育各个机制途径的相互作用,从而为新的疗法的诞生奠定基础。