Search results for "Adrenergic alpha-1 Receptor Antagonists"

Topical prazosin attenuates sensitivity to tactile stimuli in patients with complex regional pain syndrome

2015

Background The sympathetic nervous system may play an important role in certain forms of chronic pain. The main aim of this study was to determine whether functional blockade of α1-adrenoceptors would alter sensitivity to cutaneous stimulation in patients with complex regional pain syndrome (CRPS). Methods and Results In an initial study, high-performance liquid chromatography-mass spectrometry of intradermal interstitial fluid collected from the forearms of three healthy individuals established that the α1-adrenoceptor antagonist prazosin penetrated the skin barrier when mixed in Lipoderm® cream base. Next, we found that application of this cream to the forearm of 10 healthy participants a…

Functional evidence of inverse agonism in vascular smooth muscle

1996

1. In the present study, depletion of internal Ca2+ stores sensitive to noradrenaline (1 microM) in rat aorta, is the signal for the entry of extracellular Ca2+, not only to refill the stores but also, in our experimental conditions, to activate the contractile proteins. This induces an increase in the resting tone that constitutes, the first functional evidence of this Ca2+ entry. 2. The fact that methoxamine (100 microM) reproduces the same processes as noradrenaline but clonidine (1 microM) does not, indicates that alpha(1)-adrenoceptor activation is related to the increase in the resting tone observed after depletion of adrenoceptor-sensitive internal Ca2+-stores. 3. Benoxathian and WB …

A possible structural determinant of selectivity of boldine and derivatives for the alpha 1A-adrenoceptor subtype.

1996

1. The selectivity of action of boldine and the related aporphine alkaloids, predicentrine (9-O-methylboldine) and glaucine (2,9-O-dimethylboldine) and alpha 1-adrenoceptor subtypes was studied by examining [3H]-prazosin competition binding in rat cerebral cortex. WB 4101 and benoxathian were used as selective alpha 1A-adrenoceptor antagonists. 2. In the competition experiments [3H]-prazosin (0.2 nM) binding was inhibited by WB 4101 and benoxathian. The inhibition curves displayed shallow slopes which could be subdivided into high and low affinity components (pKi = 9.92 and 8.29 for WB 4101, 9.35 and 7.94 for benoxathian). The two antagonists recognized approximately 37% of the sites with h…

Therapeutic Modulation of Urinary Bladder Function: Multiple Targets at Multiple Levels

2015

Storage dysfunction of the urinary bladder, specifically overactive bladder syndrome, is a condition that occurs frequently in the general population. Historically, pathophysiological and treatment concepts related to overactive bladder have focused on smooth muscle cells. Although these are the central effector, numerous anatomic structures are involved in their regulation, including the urothelium, afferent and efferent nerves, and the central nervous system. Each of these structures involves receptors for—and the urothelium itself also releases—many mediators. Moreover, hypoperfusion, hypertrophy, and fibrosis can affect bladder function. Established treatments such as muscarinic antago…

Methodological Approach to Use Fresh and Cryopreserved Vessels as Tools to Analyze Pharmacological Modulation of the Angiogenic Growth

2016

The sprouting of new vessels is greatly influenced by the procedure chosen. We sought to optimize the experimental conditions of the angiogenic growth of fresh and cryopreserved vessels cultured in Matrigel with the aim to use this system to analyze the pharmacological modulation of the process. Segments of second-order branches of rat mesenteric resistance arteries, thoracic aorta of rat or mouse, and cryopreserved rat aorta and human femoral arteries were cultured in Matrigel for 7-21 days in different mediums, as well as in the absence of endothelial or adventitia layer. Quantification of the angiogenic growth was performed by either direct measurement of the mean length of the neovessel…

Cardiovascular and ocular safety of α1-adrenoceptor antagonists in the treatment of male lower urinary tract symptoms

2014

α1-Adrenoceptor antagonists (α-blockers) represent first-line drug treatment for male lower urinary tract symptoms. Their adverse events (AEs) include asthenia, dizziness, nasal congestion, arterial (orthostatic) hypotension and intraoperative floppy iris syndrome (IFIS).This report focuses on cardiovascular and ocular AEs of α-blockers as related to their mechanism of action and subtype selectivity.The incidence of hypotension differs between α-blockers. It is greatest with doxazosin or terazosin, but others including tamsulosin can also lead to hypotension especially upon treatment initiation. Concomitant antihypertensive medication increases the incidence of hypotension with some α-block…

Can We Clinically Distinguish Anejaculation From Retrograde Ejaculation in Patients on α1A-Blockers Therapy for Lower Urinary Tract Symptoms?

2019

To investigate the physiopathology of ejaculatory disorders (EjD) and discriminate between retrograde ejaculation (REj) and anejaculation (AEj) induced by α1A-blockers, through the association between the mean postorgasm seminal vesicle volume and the presence of sperm in midstream urine, in patients with moderate-to-severe lower urinary tract symptoms (LUTS) secondary to benign prostatic enlargement.Therapy-naïve male patients with LUTS and without previous EjD were treated with α1A-blockers. Pre- and post-treatment EjD were investigated through question 4 of the 4-item Male Sexual Function questionnaire and the Male Sexual Health Questionnaire for Ejaculatory Dysfunction Short Form (MSHQ-…

Re: Tamsulosin and the Risk of Dementia in Older Men with Benign Prostatic Hyperplasia.

2018

Pharmacologic pupil dilation as a predictive test for the risk for intraoperative floppy-iris syndrome.

2011

PURPOSE: To evaluate the effect of α1-adrenergic receptor antagonists (α1-ARAs) on pupil diameter and determine whether the diameter predicts intraoperative floppy-iris syndrome (IFIS). SETTING: Ophthalmology Section, Palermo University, Palermo, Italy. DESIGN: Prospective cohort study. METHODS: Male outpatients taking tamsulosin, α(1)-ARAs, or no α(1)-ARAs having phacoemulsification were recruited. Pupils were measured 1 month preoperatively, immediately preoperatively, and postoperatively under mesopic low (0.4 lux) and high (4.0 lux) illumination after pharmacologic dilation. The IFIS severity was graded. RESULTS: Each group comprised 50 patients. Pharmacologic dilation in both α(1)-ARA …

Cognitive and mood side effects of lower urinary tract medication

2019

Introduction: Muscarinic receptor antagonists, 5α-reductase inhibitors and α1-adrenoceptor antagonists are frequently used drug classes for the treatment of lower urinary tract symptoms including those of overactive bladder syndrome and benign prostatic enlargement/benign prostatic obstruction. Areas covered: The authors review the evidence for adverse effects of these drug classes on cognitive function, mood and other functions of the central nervous system and discuss such effects against the evidence for mechanistic plausibility. Expert opinion: Muscarinic antagonists carry a risk for impaired cognition and other brain functions that differs quantitatively between compounds, being highes…