Search results for "phosphodiester"

TREATMENT WITH SILDENAFIL PREVENTS IMPAIRMENT OF LEARNING IN RATS BORN TO PRE-ECLAMPTIC MOTHERS

2010

Pre-eclampsia is an important hypertensive pregnancy disorder and a main cause of maternal and fetal morbidity and mortality Children born from mothers with preeclampsia may present cognitive deficits The mechanisms leading to this cognitive impairment remain unclear and no treatments to improve it have been tested Pre-eclampsia is associated with impaired regulation of the nitric oxide 3 5 guanosine monophosphate cyclic (cGMP) pathway, which modulates some cognitive functions We hypothesized that alterations in the NO-cGMP pathway would be involved in the mechanisms leading to cognitive impairment in rats born to pre-eclamptic mothers and that treatment with sildenafil an inhibitor of the …

Nitric oxide synthases: regulation and function

2011

Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC 1.14.13.39). They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH(4)). All NOS bind calmodulin and contain haem. Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodila…

Microvascular Sex- and Age- Dependent Phosphodiesterase Expression

2021

Objective: The cyclic nucleotide second messengers, cAMP and cGMP, are pivotal regulators of vascular functions; their cellular levels are tightly controlled by the cyclic nucleotide hydrolases, phosphodiesterases (PDE). Biologic sex and age are recognized as independent factors impacting the mechanisms mediating both vascular health and dysfunction. This study focused on microvessels isolated from male and female rats before (juvenile) and after (adult) sexual maturity under resting conditions. We tested the hypothesis that sexual dimorphism in microvascular PDE expression would be absent in juvenile rats, but would manifest in adult rats.Methods: Abdominal skeletal muscle arterioles and v…

Rolipram inhibits airway microvascular leakage induced by platelet-activating factor, histamine and bradykinin in guinea-pigs.

1993

Abstract Rolipram (0·1–1000 μg kg−1, i.v.) reduced the increase in microvascular permeability induced by platelet-activating factor (PAF; 50 ng kg−1, i.v.) at different sites of the guinea-pig airways. Rolipram (1–100μg kg−1, i.v.) inhibited histamine (30μg kg−1, i.v.)-and bradykinin (0·3 μg kg, i.v.)-induced airway microvascular leakage. These effects of rolipram were obtained at doses which inhibit histamine (7–20 μg kg−1 min−1)-induced bronchoconstriction (IC50 = 3 ± 1 μg kg, i.v.) without depressing arterial blood pressure in the guinea-pig. Aminophylline (50 mg kg−1) did not change the effect of PAF. The anti-exudative effect of rolipram is of potential therapeutic value in asthma.

cGMP MODULATES STEM CELLS DIFFERENTIATION TO NEURONS IN BRAIN IN VIVO

2010

During brain development neural stem cells may differentiate to neurons or to other cell types. The aim of this work was to assess the role of cGMP (cyclic GMP) in the modulation of differentiation of neural stem cells to neurons or non-neuronal cells. cGMP in brain of fetuses was reduced to 46% of controls by treating pregnant rats with nitroarginine-methylester (L-NAME) and was restored by co-treatment with sildenafil.Reducing cGMP during brain development leads to reduced differentiation of stem cells to neurons and increased differentiation to non-neuronal cells. The number of neurons in the prefrontal cortex originated from stem cells proliferating on gestational day 14 was 715 +/- 14/…

ROLIPRAM INHIBITS PAF-INDUCED AIRWAY MICROVASCULAR LEAKAGE IN GUINEA-PIG - A COMPARISON WITH MILRINONE AND THEOPHYLLINE

1992

The effects of 3 phosphodiesterase (PDE) inhibitors, rolipram (PDE IV), milrinone (PDE III) and theophylline (non-selective) on PAF (50 ng kg-1; iv)-induced airway vascular leakage have been evaluated in guinea-pigs. Rolipram (3-300 micrograms kg-1; iv) reduced the increase in permeability induced by PAF at all airway levels whereas milrinone (10-1000 micrograms kg-1; iv) and theophylline (30 mg kg-1; iv) were without effects. The anti-leakage activity of rolipram may be of therapeutic value in asthma.

Haemodynamic effects of long-term administration of sildenafil in normotensive pregnant and non-pregnant rats

2011

Please cite this paper as: Pellicer B, Herraiz S, Cauli O, Rodrigo R, Asensi M, Cortijo J, Serra V, Morcillo E, Felipo V, Simon C, Pellicer A. Haemodynamic effects of long-term administration of sildenafil in normotensive pregnant and non-pregnant rats. BJOG 2011;118:615–623. Objective  To determine the effects of chronic administration of sildenafil citrateon healthy pregnant rats. Design In vivo animal experimental study. Setting  Fundacion IVI–Instituto Universitario IVI, Valencia, Spain. Sample  Pregnant and non-pregnant Wistarrats exposed to chronic administration of sildenafil. Methods  Placental cross-barrier and feto-maternal relationship levels, maternal blood pressure, and haemody…

PROSPECTIVE, RANDOMIZED, CROSSOVER COMPARISON OF SUBLINGUAL APOMORPHINE (3 mg) WITH ORAL SILDENAFIL (50 mg) FOR MALE ERECTILE DYSFUNCTION

2004

Abstract: Purpose: We established the efficacy and safety of sublingual apomorphine compared with oral sildenafil. in comparable groups of patients with erectile dysfunction (ED). Materials and Methods: This prospective, randomized, crossover study included 77 heterosexual men with ED of various etiologies and severities. A total of 62 men were randomized but only 34 were evaluable for efficacy and tolerability. The study started with a run-in period of 2 to 4 weeks. The first 4 weeks of treatment were followed by a washout period of 4 weeks, after which patients changed to the alternate treatment for an additional 4-week period. The sequence of the 2 treatments was established by a randomi…

Repression of Cyclic Adenosine Monophosphate Upregulation Disarms and Expands Human Regulatory T Cells

2011

Abstract The main molecular mechanism of human regulatory T cell (Treg)-mediated suppression has not been elucidated. We show in this study that cAMP represents a key regulator of human Treg function. Repression of cAMP production by inhibition of adenylate cyclase activity or augmentation of cAMP degradation through ectopic expression of a cAMP-degrading phosphodiesterase greatly reduces the suppressive activity of human Treg in vitro and in a humanized mouse model in vivo. Notably, cAMP repression additionally abrogates the anergic state of human Treg, accompanied by nuclear translocation of NFATc1 and induction of its short isoform NFATc1/αA. Treg expanded under cAMP repression, however,…

Comment on 'Androgenetic alopecia is associated with increased scalp hardness': role of phosphodiesterase inhibitors?

2020