Cardiovascular effects from stimulation of 5-hydroxytryptamine receptors.

摘要: Summary— The cardiovascular effects of 5-hydroxytryptamine (5-HT), consisting bradycardia or tachycardia, hypotension hypertension, and vasodilatation vasoconstriction, are mediated by three main types receptors called 5-HT1-like, 5-HT2, 5-HT3. In intact animals 5-HT elicits a short-lasting bradycardia, accompanied hypotension, via stimulation 5-HT3 located on sensory vagal nerve endings in the heart (Bezold-Jarisch reflex). nature mediating tachycardiac responses is species-dependent. Myocardial 5-HT1-like 5-HT2 subserve tachycardia cat rat, respectively. Tachycardia dog rabbit due to release catecholamines effected adrenal medulla postganglionic cardiac sympathetic fibres, pig unique as they do not resemble any characterized so far. blood pressure response usually triphasic: initial reflex (via receptors), middle pressor phase longer-lasting receptors). Vascular contraction generally (located primarily large conducting vessels), though some instances (e.g., saphenous vein, human basilar artery, porcine arteriovenous anastomoses) contractile (also) 5-HT2-like receptors. Venous dilatation arteriolar (leading increased capillary [‘nutrient’] flow) occur mainly vascular smooth muscles but also endothelium; muscle endothelial seem be heterogeneous. addition, can elicit result decreased nervous tone acting within central system inhibiting noradrenaline presynaptic action. Both these involve that appear identical. Last, knowledge involved should helpful developing 5-HT-related compounds may useful treatment migraine, peripheral diseases.