Tridax procumbens is commonly used in traditional medicine in southern part of Nigeria for the treatment of hypertension. However, the mechanism of its antihypertensive properties remains unclear. Attempts were made to investigate the properties of direct actions of aqueous extract of the leaves of T. procumbens on mechanical responses of smooth muscles in aortic ring preparations isolated from the rat. Endothelium-intact aortic rings, isolated from the normotensive rats, had been pre-contracted with noradrenaline, and cumulative addition of the aqueous extract (0.15–1.05 mg/mL) to the bathing fluid induced a concentration-dependent relaxation. Aqueous extract of T. procumbens also attenuated the contractile responses to KCl and shifted the concentration-response curve to the right. The contractile responses to serotonin were also attenuated and the concentration-response curve was shifted to the right in the presence of the extract. The results of this study indicated that aqueous leaf extract of T. procumbens possesses vasodilatory effects on the aortic smooth muscles isolated from the rat. Based on these results, a possible mechanism involved in the relaxing actions of the extract on vascular smooth muscle was discussed. The results of this study may provide a scientific basis for the use of this extract to the treatment of hypertension in Nigerian traditional medicine.
Electrogastrograms (EGGs) were recorded in human subjects (n=58) at 16 locations on the thoraco-abdominal surface before (at rest) and during the stress of the mirror drawing test (MDT) and after having a test meal. The power amplitude ratios and power content ratios of MDT to rest (MDT/rest) and postprandial state to rest (PPR/rest) were compared between gastric channels 5 and 8, and the infraumbilical channels 12, 13, 14, 15, and 16. Generally, the ratio of the 3-cpm group in channels 5 and 8 was lower than that of the infraumbilical channels 12–16 during MDT. In contrast, the ratios were higher in the epigastric channels than in the infraumbilical channels after a test meal. Significant differences between the epigstric and infraumbilical channels were found in the comparisons of the power content ratios. The infraumbilical channels were facilitated and the epigastric channels inhibited during MDT. After eating a meal, in contrast, the postprandial epigastric 3-cpm EGGs were facilitated. The epigastric 3-cpm EGG activity reflects gastric myoelectric activity, while the infraumbilical 3-cpm activity reflects that of the colon. Therefore, it is suggested that the acute stress of the MDT generally inhibited the gastric EGG and facilitated the colonic EGG, indicating gastric inhibition and colonic facilitation. The topographic EGG maps of the power content ratios and the absolute power ratios visually confirmed these findings.
Sugammadex can encapsulate the steroid-based neuromuscular blocker molecule and results in rapid reversal of neuromuscular blockade induced by rocuronium and vecuronium. However, several cases of bronchospasm after the administration of sugammadex have been reported. The current study was carried out to determine whether sugammadex directly affects smooth muscle function of the airways. The ring strips of left main bronchi were isolated from male Wistar rats and isometric forces were measured. In the isolated bronchial smooth muscle tissues, sugammadex (10–8 – 10 –3 M) had no effect on baseline tension or the acetylcholine (ACh; 30 μM)-induced sustained contraction. Moreover, sugammadex did not affect bronchial smooth muscle responsiveness to ACh. These findings indicate that sugammadex itself does not affect contractile function in bronchial smooth muscle of the rat.