Anna Maria Condino

Involvement of β3-adrenoceptors in the inhibitory control of cholinergic activity in human bladder: Direct evidence by [3H]-acetylcholine release experiments in the isolated detrusor

Bladder overactivity (OAB) is a multifactorial bladder disorder that requires therapeutics superior to the current pharmacological treatment with muscarinic antagonists. β3-adrenoceptor (β3-ADR) agonists represent a novel promising approach that differently addresses the parasympathetic pathway, but the clinical efficacy of these drugs has not been fully elucidated to date. Therefore, we aimed to study the pharmacological mechanisms activated by β3-ADR agonists at muscular and neural sites in the isolated human bladder. Detrusor smooth muscle strips obtained from male patients undergoing total cystectomy were labelled with tritiated choline and stimulated with electrical field stimulation (EFS). EFS produced smooth muscle contraction and simultaneous acetylcholine ([(3)H]-ACh) release, which mostly reflects the neural origin of acetylcholine. Isoprenaline (INA), BRL37344 and mirabegron inhibited the EFS-evoked contraction and [(3)H]-ACh release in a concentration-dependent manner, yielding concentration-response curves (CRCs) that were shifted to the right by the selective β3-ADR antagonists L-748,337 and SR59230A. Based on the agonist potency estimates (pEC50) and apparent affinities (pKb) of antagonists evaluated from the CRCs of agonists, our data confirm the occurrence of β3-ADRs at muscle sites. Moreover, our data are consistent with the presence of inhibitory β3-ADRs that are functionally expressed at the neural site. Taken together, these findings elucidate the mechanisms activated by β3-ADR agonists because neural β3-ADRs participate in the inhibition of detrusor motor drive by reducing the amount of acetylcholine involved in the cholinergic pathway.

An appraisal of recently patented compounds for bladder overactivity and urinary incontinence

Bladder overactivity and urinary incontinence are lower urinary tract syndromes for which there is no adequate pharmacological treatment. The latter condition is associated with an involuntary loss of urine causing a hygienic and social concern to the patient. Recently, central and peripheral mechanisms that control bladder storage and voiding processes have been partly addressed and clarified. Novel antimuscarinic agents, as well as newer formulations of available drugs and selective antagonists at α1D-receptors, have been patented, in addition to selective agonists at the β3-adrenoceptor and selective antagonists at 5-hydroxytryptamine, subtype 1A and 7 (5-HT1A and 5-HT7) receptors. Other potential therapeutic options include neurokinin type 1 and 2 (NK1/NK2) tachykinin receptor antagonists and potassium channel openers. The aforementioned agents may contribute to the pharmacological armamentarium in urology treatment, although their therapeutic effectiveness and safety profile remain to be validated in the clinical setting.

Isolated porcine bronchi provide a reliable model for development of bronchodilator anti-muscarinic agents for human use

Background and purpose: In human airways, muscarinic acetylcholine receptors (mAChRs) exert a predominant role in the control of airways resistance and anti‐muscarinic agents are currently included in the pharmacological treatment of chronic obstructive pulmonary disease (COPD). However, the development of more effective mAChR antagonists is hampered by considerable species variability in the ultrastrucural and functional control of airway smooth muscle, making extrapolation of any particular animal model questionable. This study was designed to characterize the mAChRs in a bronchial preparation from pigs, animals considered to provide close models of human biology.

Myofibrillar protein overdegradation in overweight patients with chronic heart failure: the relationship to serum potassium levels.

OBJECTIVES Muscle release of the amino acid 3-methyl-histidine (3MH) is a sensitive index of myofibrillar protein overdegradation (MPO). We hypothesized that patients with chronic heart failure (CHF) could have increased muscle release of 3MH, which in turn reflects MPO, and that serum electrolyte sodium (Na(+)) and potassium (K(+)) levels may be associated with this 3MH muscle release. METHODS Thirty-one overweight outpatients (body mass index, 27 ± 4.4 kg/m(2); 22 men and 9 women; age, 56 ± 8.7 y) with clinically stable CHF were studied. After a 24-hour meat-free diet and overnight fasting, patients underwent blood sampling from a cannulated arm vein (V) and concomitantly from the arterial artery (A) to determine plasma 3MH levels and to calculate the A-V difference. Serum levels of Na(+) and K(+) in the venous blood were determined, and the Na(+)/K(+) ratio was calculated. Ten healthy subjects who were matched for gender, age, and body mass index served as controls and underwent the same protocol as the patients with CHF. RESULTS The patient group had higher arterial (P = 0.02) and venous (P = 0.005) 3MH levels but a similar A-V 3MH difference (P = 0.28) as compared with the controls. Within the CHF group, 67.7% of patients released 3MH, which resulted in a negative A-V value (P < 0.02 as compared with controls). In patients with CHF, the A-V 3MH difference correlated positively with the serum K(+) level (r = 0.62; P = 0.0002) and negatively with Na(+)/K(+) ratio (r = -0.55; P = 0.002). No association was found between the A-V 3MH difference and the Na(+) level. CONCLUSIONS The study demonstrated the existence of MPO in resting overweight patients with CHF, thereby suggesting that low serum levels of K(+) may contribute to MPO.

Plasma Amino Acid Abnormalities in Chronic Heart Failure. Mechanisms, Potential Risks and Targets in Human Myocardium Metabolism

The goal of this study was to measure arterial amino acid levels in patients with chronic heart failure (CHF), and relate them to left ventricular function and disease severity. Amino acids (AAs) play a crucial role for heart protein-energy metabolism. In heart failure, arterial AAs, which are the major determinant of AA uptake by the myocardium, are rarely measured. Forty-one subjects with clinically stable CHF (New York Heart Association (NYHA) class II to IV) were analyzed. After overnight fasting, blood samples from the radial artery were taken to measure AA concentrations. Calorie (KcalI), protein-, fat-, carbohydrate-intake, resting energy expenditure (REE), total daily energy expenditure (REE × 1.3), and cardiac right catheterization variables were all measured. Eight matched controls were compared for all measurements, with the exception of cardiac catheterization. Compared with controls, CHF patients had reduced arterial AA levels, of which both their number and reduced rates are related to Heart Failure (HF) severity. Arterial aspartic acid correlated with stroke volume index (r = 0.6263; p < 0.0001) and cardiac index (r = 0.4243; p = 0.0028). The value of arterial aspartic acid (µmol/L) multiplied by the cardiac index was associated with left ventricular ejection fraction (r = 0.3765; p = 0.0076). All NYHA groups had adequate protein intake (≥1.1 g/kg/day) and inadequate calorie intake (KcalI < REE × 1.3) was found only in class IV patients. This study showed that CHF patients had reduced arterial AA levels directly related to clinical disease severity and left ventricular dysfunction.

Despite Inflammation, Supplemented Essential Amino Acids May Improve Circulating Levels of Albumin and Haemoglobin in Patients after Hip Fractures

Essential amino acids (EAAs) are nutritional substrates that promote body protein synthesis; thus we hypothesised that their supplementation may improve circulating albumin (Alb) and haemoglobin (Hb) in rehabilitative elderly patients following hip fractures (HF). Out of the 145 HF patients originally enrolled in our study, 112 completed the protocol. These subjects were divided into two randomised groups, each containing 56 patients. For a period of two months, one group (age 81.4 ± 8.1 years; male/female 27/29) received a placebo, and the other (age 83.1 ± 7.5 years; male/female 25/31) received 4 + 4 g/day oral EAAs. At admission, the prevalence of both hypoAlb (<3.5 g/dL) and hypoHb (<13 g/dL male, <12 g/dL female) was similar in the placebo group (64.3% hypoAlb, 66% hypoHb) and the treated group of patients (73.2% hypoAlb, 67.8% hypoHb). At discharge, however, the prevalence of hypoAlb had reduced more in EAAs than in placebo subjects (31.7% in EAAs vs. 77.8% in placebo; p < 0.001). There was a 34.2% reduction of anaemia in hypoHb in EAA subjects and 18.9% in placebo subjects, but the difference was not statistically significant. Oral supplementation of EAAs improves hypoAlb and, to a lesser extent, Hb in elderly rehabilitative subjects with hip fractures. Anaemia was reduced in more than one third of patients, which, despite not being statistically significant, may be clinically relevant.

Inflammation and rehabilitation outcomes in patients with nontraumatic intracranial haemorrhage

BACKGROUND Systemic inflammation and its impact on rehabilitation for patients with non-traumatic haemorrhagic injury (HBI) sequelae has not yet been adequately documented. OBJECTIVE AND METHODS We therefore considered 31 patients with HBI, to determine the serum levels of inflammatory markers (C-Reactive Protein, CRP and or interleukine-6, IL-6) to establish their impact on functional status (Functional Independence Measure, FIM: 18 indicating the worst performance and 126, a normal score). RESULTS The results showed an inflammation prevalence (CRP >0.5 mg/dl and/or IL 6 >7 pg/ml) of 74.2% at admission to Rehab. FIM reduction was more pronounced in inflamed compared to non-inflamed subjects (p <  0.05) and significantly correlated with blood variables sensitive to inflammation, such as alpha 1 globulin (r = - 0.565) and neutrophil/ lymphocyte ratio (r = - 0.52), CRP (r = - 0.365). At discharge from Rehab, the inflammation rate diminished. Inflamed patients showed similar gains in FIM score as their controls. In the entire population, the FIM gain was significantly associated with a gain in serum albumin, only (r = +0.56). CONCLUSIONS We conclude that systemic inflammation is prevalent in HBI patients and contributes to reduce patient functional status. However, during the Rehab stage, inflammation does not hinder the improvement rate of functional capacity.