The left anterior descending artery arising from the right sinus of Valsalva: A case report

Coronary artery anomalies occur in less than 1% of patients who undergo coronary angiography and they account for 1% to 2% of all cases of congenita heart disease. The most commonly encountered anomaly, the circumflex artery originating from the right coronary artery or the right sinus of Valsalva, is usually well tolerated. The patient in the case presented here was found to have a left anterior descending artery arising from the right sinus of Valsalva - a situation that is very rarely encountered

Characterization of 5-HT receptors on human pulmonary artery and vein: functional and binding studies

1. This study aimed to investigate the 5-hydroxytryptamine (5-HT) receptors mediating contraction of ring preparations isolated from human pulmonary arteries and veins. In functional studies, the responses to 5-HT, sumatriptan, ergotamine, serotonin-O-carboxymethyl-glycyl-tyrosinamide (SCMGT), α-methyl 5-HT (α-Me) and 2-methyl 5-HT (2-Me) were studied with WAY100635, GR127935, ritanserin, zacopride and SB204070 as antagonists. 2. All agonists produced concentration-dependent contractions of human pulmonary artery and vein preparations. The order of potency (−log EC(50) values) was ergotamine (6.88)>5-HT (6.41)⩾SCMGT (6.20)=sumatriptan (6.19) ⩾α-Me (6.04) in the artery, and ergotamine (7.84)>5-HT (6.96)>sumatriptan (6.60)=α-Me (6.56)>SCMGT (6.09) in the vein. The potency of each agonist, except for SCMGT, was greater in vein than in artery preparations. Contractile responses to 5-HT were similar in intact and endothelium-denuded preparations but responses to sumatriptan were enhanced in artery rings without endothelium. 3. GR127935 (1 nM to 0.5 μM) produced an unsurmountable antagonism of the response to 5-HT, sumatriptan, ergotamine and SCMGT. Ritanserin (1 nM to 1 μM) also reduced the maximum contractile responses to 5-HT, ergotamine and α-Me in artery and vein preparations without affecting those to sumatriptan and SCMGT. In endothelium-denuded preparations, surmountable antagonism of sumatriptan by GR127935 (in the presence of ritanserin) and of α-Me by ritanserin (in the presence of GR127935) allowed for the calculation of the apparent pK(B) values of GR127935 (9.17±0.11 in artery and 9.11±0.05 in vein) and ritanserin (8.82±0.09 in artery and 8.98±0.12 in vein). 4. WAY100635 (1 nM to 1 μM), zacopride (1 nM to 1 μM), or SB204070 (1 nM) did not significantly alter the concentration-response curves for 5-HT, sumatriptan, ergotamine, SCMGT or 2-Me in human pulmonary artery or vein thus indicating that 5-HT(1A), 5-HT(3) and 5-HT(4) receptors are presumably not involved in the contractile response to these agonists. 5. Binding studies using selective radioligands for different 5-HT receptors could not detect the presence of 5-HT(1A) receptor binding in human pulmonary blood vessels whereas the 5-HT(1B/1D) radioligand [(3)H]-5-CT significantly labelled a population of specific binding sites in both vessel types. The presence of 5-HT(2A) receptors could also be inferred from the level of binding of [(3)H]-ketanserin to membranes obtained from human pulmonary vessels, although significance could not be reached for arteries. 5-HT(4) specific receptor binding was scarce in veins and absent in the case of arteries. 6. These findings indicate that the human pulmonary artery and vein have a mixed functional population of 5-HT(1B/1D) and 5-HT(2A) receptors mediating the contractile response to 5-HT which is consistent with results of the binding studies