Brachial artery hemodynamic response to acute converting enzyme inhibition by enalaprilat in essential hypertension

Docking Studies of Methylthiomorpholin Phenols (LQM300 Series) with Angiotensin-Converting Enzyme (ACE)

A main target in the treatment of hypertension is the angiotensin-converting enzyme (ACE). This enzyme is responsible for producing angiotensin II, a potent vasoconstrictor. Therefore, one of the targets in the treatment of hypertension is to inhibit ACE activity. Hence, this study's aim is to use computational studies to demonstrate that the proposed heterocyclic compounds have a molecular affinity for ACE and that, furthermore, these heterocyclic compounds are capable of inhibiting ACE activity, thus avoiding the production of the vasopressor Angiotensin II. All this using computer-aided drug design, and studying the systems, with the proposed compounds, through molecular recognition process and compared with the compounds already on the market for hypertension.

Occurrence and distribution of multi-class pharmaceuticals and their active metabolites and transformation products in the Ebro river basin (NE Spain)

The present work reports the occurrence of pharmaceuticals and their metabolites and transformation products (TPs) in the Ebro river basin (NE Spain). Twenty-four samples of water collected along the basin were analysed using a fully automated method based on on-line turbulent chromatography-liquid chromatography-tandem mass spectrometry (TFC-LC-MS/MS). In total, 17 metabolites, 7 of them with remaining pharmacologic activity, and 2 transformation products, along with 58 parent pharmaceuticals are analysed. Metabolites and TPs were found at concentrations of the same order of magnitude as their corresponding parent pharmaceuticals, with the exception of 10,11-epoxi-carbamazepine which was found at approximately 10 times higher concentration than its corresponding parent pharmaceutical carbamazepine. In general, levels of all target compounds were below 100 ng L(-1), with the exception of 14 compounds; among them the aforementioned 10,11-epoxicarbamazepine with a maximum concentration of more than 1600 ng L(-1). The analgesic propyphenazone, the psychiatric drug carbamazepine, the antibiotics clarithromycin and sulfadiazine, the cardiovascular drug propranolol, the antineoplastic tamoxifen and 1 pharmacologically active metabolite salicylic acid were found to be ubiquitous (detected in all samples). Smaller tributaries generally show higher concentrations than the main river Ebro, due to lower dilution of WWTP effluents discharged.

Effects of an angiotensin converting enzyme inhibitor, ramipril, on intracranial circulation in healthy volunteers. off

1. The effects of a single oral dose (10 mg) of ramipril on (a) systemic haemodynamics (arterial pressure, cardiac output), (b) carotid artery haemodynamics (blood flow and diameter, pulsed Doppler technique), (c) intracranial haemodynamics (middle cerebral artery mean blood velocity, transcranial Doppler technique), and (d) renin-angiotensin system (plasma converting enzyme and renin activities) have been investigated and compared with those of a placebo during the 24 h period following administration in a randomized, double-blind and cross-over study performed in six healthy volunteers. 2. Ramipril induced a strong and sustained inhibition of plasma converting enzyme activity (-96% at 4 h, -63% at 24 h) and an increase in plasma renin activity (+993% at 8 h). 3. As compared with placebo, ramipril did not significantly affect arterial blood pressure, heart rate, cardiac output and total peripheral resistance. 4. Ramipril significantly increased carotid blood flow (by 27% at 8 h) without significantly changing carotid artery diameter, indicating, given the unchanged arterial pressure, an arteriolar vasodilation in the carotid territory. 5. The middle cerebral artery mean blood flow velocity underwent spontaneous modifications during the placebo period but these changes were not affected by ramipril. This lack of influence of ramipril on intracranial haemodynamics suggests that the drug-induced arteriolar vasodilation and increase in carotid blood flow only concern the extracranial, musculo-cutaneous part of the carotid territory.

Comparative haemodynamic effects of ketanserin and ritanserin in the proximal and distal upper limb circulations of hypertensive patients

The effects of ketanserin (40 mg p.o.) on blood pressure and brachial haemodynamics (brachial artery diameter, brachial blood velocity and blood flow) have been compared in a double-blind study with those of ritanserin (10 mg p.o.) and placebo. Haemodynamic parameters were measured before and 1 h after treatment. Patients with mild to moderate essential hypertension participated in this study, 6 each on ketanserin, ritanserin and placebo. Placebo significantly reduced heart rate and did not modify the other parameters. Compared to placebo, ketanserin significantly reduced systolic and diastolic blood pressure, increased brachial blood velocity and flow, and decreased forearm vascular resistance. Compared to placebo, ritanserin slightly decreased blood pressure and slightly increased blood flow, but neither effect was significant. When blood circulation to the hand was excluded, neither ketanserin nor ritanserin modified the proximal arterial resistance or blood flow. It is concluded that the actions of ketanserin and ritanserin essentially occurred in the distal part of the upper limb, and alpha 1-receptor blockade is probably involved.