bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of recombinant human granulocyte‐colony stimulating factor on vascular dysfunction and splanchnic ischaemia‐reperfusion injury
Authors: Squadrito Francesco , Altavilla Domenica , Squadrito Giovanni , Campo Giuseppe M , Ioculano Mariapatrizia , Ammedolia Letteria , Arlotta Mariarita , Saitta Antonino , Caputi Achille P 
Published: August 2006

The aim of our study was to investigate the effects of recombinant human granulocyte‐colony stimulating factor in a rat model of splanchnic ischaemia‐reperfusion injury.
Male anaesthetized rats were subjected to clamping of the splanchnic arteries for 45 min. This surgical procedure resulted in an irreversible state of shock (splanchnic artery occlusion shock; SAO shock). Sham operated animals were used as controls. Survival rate, serum tumour necrosis factor‐α (TNF‐α), neutrophil count, bone marrow myeloid precursor cells, myeloperoxidase activity (MPO; studied as a quantitative means to assess leukocyte accumulation), mean arterial blood pressure and the responsiveness of aortic rings to phenylephrine (PE, 1 nm–10 μm) were studied.
SAO shocked rats had a decreased survival rate (0% at 4 h of reperfusion, while sham shocked rats survived more than 4 h), increased serum levels of TNF‐α (201±10 u ml−1; sham shocked rats=undetectable), neutropenia, enhanced MPO activity in the ileum (0.11±0.06 u × 10−3 g−1 tissue; sham shocked rats=0.02±0.001 u × 10−3 g−1 tissue) and in the lung (1.5±0.2 u × 10−3 g−1 tissue; sham shocked rats=0.19±0.05 u × 10−3 g−1 tissue) and unchanged bone marrow myeloid precursor cells. Furthermore aortic rings from shocked rats showed a marked hyporeactivity to PE.
Administration of recombinant human granulocyte colony stimulating factor (rh G‐CSF; 5, 10 and 20 μg kg−1 5 min following the release of occlusion) increased in a dose‐dependent manner survival rate (90% at 4 h of reperfusion with the dose of 20 u × 10−3 g kg−1), reduced serum TNF‐α (13±5 u ml−1) and MPO activity in the ileum (0.065±0.002 u × 10−3 g−1 tissue) and in the lung (0.7±0.03 μ g kg−1 tissue), improved neutropenia and mean arterial blood pressure but did not modify bone marrow myeloid progenitor cells. Furthermore rh G‐CSF, either in vivo or in vitro (200 nm for 1 h in the organ bath), restored to control values the hyporeactivity to PE. Finally rh G‐CSF potently inhibited the activity of inducible nitric oxide synthase in peritoneal macrophages activated with endotoxin.
Our results suggest that rh G‐CSF protects against splanchnic ischaemia reperfusion injury by a mechanism(s) that does not depend upon its haematopoietic effects.

British Journal of Pharmacology (1997) 120, 333–339; doi:10.1038/sj.bjp.0700904
The antihypertensive effect of orally administered nifedipine‐loaded nanoparticles in spontaneously hypertensive rats
Authors: Kim Young Il , Fluckiger Laurence , Hoffman Maurice , Lartaud‐Idjouadiene Isabelle , Atkinson Jeffrey , Maincent Thilippe 
Published: August 2006

The therapeutic use of nifedipine is limited by the rapidity of the onset of its action and its short biological half‐life. In order to produce a form devoid of these disadvantages we made nanoparticles of nifedipine from three different polymers, poly‐ɛ‐caprolactone (PCL), polylactic and glycolic acid (1:1) copolymers (PLAGA), and Eudragit RL/RS (Eudragit). Nifedipine in polyethylene glycol 400 (PEG) solution was used as a control.
The average diameters of the nanoparticles ranged from 0.12 to 0.21 μm; the encapsulation ratio was 82% to 88%.
In spontaneously hypertensive rats (SHR), the initial rapid fall in systolic arterial blood pressure following oral administration of nifedipine in PEG solution (from 193 ± 3 to 102 ± 2 mmHg) was not seen following administration of the same dose in Eudragit nanoparticles (from 189 ± 2 to 156 ± 2 mmHg); with PCL and PLAGA nanoparticles the initial fall in blood pressure was significantly reduced (nadirs PCL 124 ± 2 and PLAGA 113 ± 2 mmHg). Ten hours following administration, blood pressure in rats administered the nifedipine/PEG preparation had returned to normal (183 ± 3 mmHg) whereas that of animals given nifedipine in nanoparticles (PCL 170 ±3, PLAGA 168 ± 2, Eudragit 160 ±3 mmHg) was still significantly reduced.
All of the nanoparticle dosage forms decreased Cmax and increased Tmax and the mean residence time (MRT) values. Relative bioavailability was significantly increased with Eudragit nanoparticles compared to the nifedipine/PEG solution.
There was an inverse linear correlation between the fall in blood pressure and plasma nifedipine concentration with all preparations.
The nanoparticle nifedipine preparations represent sustained release forms with increased bioavailability, a less pronounced initial antihypertensive effect and a long‐lasting action.
Effect of adrenergic and nitrergic blockade on experimental ileus in rats
Authors: De Winter Benedicte Y. , Boeckxstaens Guy E. , De Man Joris G. , Moreels Tom G. , Herman Arnold G. , Pelckmans Paul A. 
Published: August 2006

In a rat model of experimental ileus, the effect of blockade of adrenergic and nitrergic neurotransmission was studied on the intestinal transit of Evans blue.
Ether anaesthesia and skin incision had no influence on the transit. Laparotomy significantly inhibited the transit of Evans blue. This inhibition was even more pronounced when the small intestine was manipulated.
Reserpine (5 mg kg−1), a drug that blocks adrenergic neurotransmission, completely reversed the inhibition of the transit induced by laparotomy but only partially reversed that induced by laparotomy with manipulation of the small intestine.
Nω‐nitro‐L‐arginine (L‐NOARG, 5 mg kg−1), a nitric oxide synthase inhibitor, completely reversed the reserpine‐resistant inhibition induced by laparotomy with manipulation of the small intestine. The effect of L‐NOARG was prevented by concomitant administration of L‐arginine. L‐Arginine itself slightly, but significantly enhanced the inhibition. S‐methylisothiourea and aminoguanidine, selective inhibitors of the inducible NO synthase, had no effect on the transit after the three operations.
Treatment of the rats with reserpine plus L‐NOARG had no additional effect on the transit after laparotomy as compared to reserpine alone. However, reserpine plus L‐NNA completely reversed the inhibition of the transit induced by laparotomy with manipulation of the small intestine.
These findings support the involvement of adrenergic pathways in the pathogenesis of ileus and suggest that the additional inhibitory effect of mechanical stimulation results from an enhanced release of NO by the constitutive NO synthase.
The NK1 receptor and its participation in the synergistic enhancement of corneal epithelial migration by substance P and insulin‐like growth factor‐1
Authors: Nakamura Masatsugu , Ofuji Keiko , Chikama Tai‐ichiro , Nishida Teruo 
Published: August 2006

We have previously shown that substance P (SP) and insulin‐like growth factor‐1 (IGF‐1) act synergistically to enhance the migration of rabbit corneal epithelial cells in an organ culture model. The present study was designed to identify the epithelial cell SP receptor that participates in this synergistic effect.
Rabbit corneal blocks were incubated for 24 h, then the length of the path of epithelial migration was measured. Reagents tried in the TC‐199 culture medium, in the presence or absence of IGF‐1, were: SP, agonists of tachykinin receptors NK1; NK2or NK3 and antagonists of tachykinin receptors NK1 or NK2.
The binding characteristics of SP receptors were examined in rabbit cultured corneal epithelial cells by binding assays with [125I]‐SP in the presence or absence of excess unlabelled SP or ligands of NKl, NK2 or NK3 receptors.
As was demonstrated previously, SP and IGF‐1 stimulated epithelial migration when they were added to the culture medium together, but individually they had no effect. NK1 agonists had the same synergistic effect with IGF‐1 as did SP, but the NK2 and NK3 agonists did not. Furthermore, the NK1 antagonist abolished the synergistic effect of SP and IGF‐1, but the NK2 antagonist had no effect.
SP bound specifically to rabbit cultured corneal epithelial cells. The binding affinity was 0.44 nM and there were 2.43 × 104 binding sites per cell. The NK1 ligand competed, in a dose‐dependent fashion, with the binding of SP to corneal epithelial cells, but neither the NK2 nor NK3 ligand affected binding.
We conclude that the SP receptor in rabbit corneal epithelial cells is NK1 and that this receptor participates in the synergistic enhancement of corneal epithelial migration by SP and IGF‐1. The precise mechanism(s) of this interaction requires more study. These findings imply that both neural and humoral factors are essential for the maintenance and healing of corneal epithelium.
Subunit‐dependent interaction of the general anaesthetic etomidate with the γ‐aminobutyric acid type A receptor
Authors: Hill‐Venning Claire , Belelli Delia , Peters John A , Lambert Jeremy J 
Published: August 2006

The GABA modulating and GABA‐mimetic actions of the general anaesthetic etomidate were examined in voltage‐clamp recordings performed on Xenopus laevis oocytes induced, by cRNA injection, to express human recombinant γ‐aminobutyric acidA (GABAA) receptor subunits.
Currents mediated by recombinant receptors with the ternary subunit composition αxβyγ2L (where x=1,2,3 or 6 and y=1 or 2), in response to GABA applied at the appropriate EC10, were enhanced by etomidate in a manner that was dependent upon the identity of both the α and β subunit isoforms.
For the β2‐subunit containing receptors tested, the EC50 for the potentiation of GABA‐evoked currents by etomidate (range 0.6 to 1.2 μm) was little affected by the nature of the α subunit present within the hetero‐oligomeric complex. However, replacement of the β2 by the β1 subunit produced a 9–12 fold increase in the etomidate EC50 (6 to 11 μm) for all α‐isoforms tested.
For α1, α2 and α6, but not α3‐subunit containing receptors, the maximal potentiation of GABA‐evoked currents by etomidate was greater for β2‐ than for β1‐subunit containing receptors. This was most clearly exemplified by receptors composed of α6β1γ2L compared to α6β2γ2L subunits, where a maximally effective concentration of etomidate potentiated currents evoked by GABA at EC10 to 28±2% and 169±4% of the maximal GABA response, respectively.
For α1 subunit‐containing receptors, the potency and maximal potentiating effect of either pentobarbitone or propofol was essentially unaffected by the β subunit isoform contained within the receptor complex. The potency of the anaesthetic neurosteroid 5α‐pregnan‐3α‐ol‐20‐one was marginally higher for β1 rather than the β2 subunit‐containing receptor, although its maximal effect was similar at the two receptor isoforms.
The GABA‐mimetic action of etomidate was supported by β2‐ but not β1‐subunit containing receptors, whereas that of pentobarbitone or propofol was evident with either β isoform. For β2‐subunit containing receptors, both the agonist EC50 and the maximal current produced by etomidate were additionally influenced by the α isoform.
It is concluded that the subtype of β‐subunit influences the potency with which etomidate potentiates GABA‐evoked currents and that the β isoform is a crucial determinant of the GABA‐mimetic activity of this compound. The nature of the α‐subunit also impacts upon the maximal potentiation and activation that the compound may elicit. Such pronounced influences may aid the identification of the site that recognises etomidate. More generally, these results provide a clear example of structural specificity in anaesthetic action.

British Journal of Pharmacology (1997) 120, 749–756; doi:10.1038/sj.bjp.0700927
Protection by amylin of gastric erosions induced by indomethacin or ethanol in rats
Authors: Guidobono F. , Pagani F. , Ticozzi C. , Sibilia V. , Pecile A. , Netti C. 
Published: August 2006

The effect of amylin on gastric ulcers induced by oral administration of indomethacin (Indo, 20 mg kg−1 at a dosing volume of 5 ml) or ethanol 50% (EtOH, 1 ml/rat) was investigated in conscious rats.
Amylin given intracerebroventricularly (0.22, 0.66 and 2.2 μg/rat, i.c.v.) demonstrated a dose‐dependent cytoprotective effect against both Indo and EtOH‐induced ulcers. In contrast, amylin, given subcutaneously at doses effective in inhibiting acid gastric secretion (2.5, 10 and 40 μg kg−1, s.c), did not show any cytoprotective effect.
The interaction between amylin and endogenous nitric oxide (NO) in the maintenance of gastric mucosal integrity was investigated by pretreating the rats with a selective inhibitor of NO‐synthesis, NG‐nitro‐L‐arginine methyl ester (l‐NAME, 25 and 70 mg kg−1, s.c). Administration of L‐NAME to rats did not significantly increase the degree of the Indo‐induced ulcer index and was not able to remove the protective effect of amylin on Indo‐induced ulcers, thus excluding a role for endogenous NO in mediating the protective effect of this peptide.
To determine whether the cytoprotective effect of amylin was mediated by endogenous prostaglandins, we studied the effect of amylin (2.2 μg/rat, i.c.v.) on EtOH‐induced ulcers in rats pretreated with Indo (10 mg kg−1, s.c.) to inhibit prostanoid biosynthesis; Indo was injected 30 min before amylin and EtOH after a further 30 min. Pretreatment with Indo did not significantly increase the ulcer index induced by EtOH but counteracted the ability of amylin to prevent the ulcer formation.
These findings suggest that amylin exerts a gastroprotective activity that is not strictly related to inhibition of acid gastric secretion and can be partly explained through a prostaglandin‐dependent mechanism mediated by receptors for the peptide in the brain. Amylin might be considered as a new brain‐gut peptide.
Role of N‐, P‐and Q‐type voltage‐gated calcium channels in transmitter release from sympathetic neurones in the mouse isolated vas deferens
Authors: Waterman Sally A. 
Published: August 2006

N‐type voltage‐gated calcium channels are known to play an important role in transmitter release from autonomic neurones, and recent studies have demonstrated that non‐N‐type calcium channels are also involved. The calcium channels coupled to transmitter release from sympathetic neurones in the mouse isolated vas deferens were investigated in the present study.
Contractions of the mouse vas deferens were evoked by electrical stimulation at 1–50 Hz. The contractions were entirely nerve‐mediated, since they were abolished by tetrodotoxin, and were used as an indirect measure of transmitter release.
The N‐type calcium channel blocker, ω‐conotoxin GVIA, inhibited contractions in a concentration‐dependent manner, with a maximal effect at 30 nM. Contractions evoked by stimulation frequencies less than 10 Hz were abolished, and those evoked by 20 and by 50 Hz stimulation were decreased in amplitude by 51.3 ± 13.9% and 9.3±2.6%, respectively.
The N‐, P‐and Q‐type channel blocker, ω‐conotoxin MVIIC, inhibited contractions in a concentration‐dependent manner and caused greater maximum inhibition than ω‐conotoxin GVIA, suggesting an action on P‐and/or Q‐type channels, in addition to N‐type.
The P‐type channel blocker, ω‐agatoxin IVA, alone did not have a significant effect at concentrations up to 300 nM, but inhibited contractions in the presence of ω‐conotoxin GVIA. Subsequent addition of ω‐conotoxin MVIIC abolished the remaining contractions. Identical results were obtained when the three toxins were tested cumulatively on the purinergic and noradrenergic components of the contraction in the presence of 0.3 μM prazosin and following desensitization to 10μM μ,β‐methylene adenosine 5′‐triphosphate (α,β‐MeATP), respectively.
The results suggest that N‐, P‐and Q‐type channels are involved in the release of noradrenaline and ATP from sympathetic neurones in the mouse vas deferens.
The identification of an orally active, nonpeptide bradykinin B2 receptor antagonist, FR173657
Authors: Asano Masayuki , Inamura Noriaki , Hatori Chie , Sawai Hiroe , Fujiwara Tatsujiro , Katayama Akira , Kayakiri Hiroshi , Satoh Shigeki , Abe Yoshito , Inoue Takayuki , Sawada Yuki , Nakahara Kunio , Oku Teruo , Okuhara Masakuni 
Published: August 2006

An orally active, nonpeptide bradykinin (BK) B2 receptor antagonist, FR173657 (E)‐3‐(6‐acetamido‐3‐pyridyl)‐N‐[N‐[2‐4‐dichloro‐3‐[(2‐methyl‐8‐quinolinyl) oxymethyl]phenyl]‐N‐methylaminocarbonyl‐methyl]acrylamide) has been identified.
This compound displaced [3H]‐BK binding to B2 receptors present in guinea‐pig ileum membranes with an IC50 of 5.6 × 10−10 M and in rat uterus with an IC50 of 1.5 × 10−9 M. It did not inhibit different specific radio‐ligand binding to other receptor sites.
In human lung fibroblast IMR‐90 cells, FR173657 displaced [3H]‐BK binding to B2 receptors with an IC50 of 2.9 × 10−9 M and a Ki of 3.6 × 10−10 M, but did not reduce [3H]‐des‐Arg10‐kallidin binding to B1, receptors.
In guinea‐pig isolated preparations, FR173657 antagonized BK‐induced contractions with an IC50 of 7.9 × 10−9 M, but did not antagonize acetylcholine or histamine‐induced contractions even at a concentration of 10−6 M. FR173657 caused parallel rightward shifts of the concentration‐response curves to BK at concentrations of 10−9 M and 3.2 × 10−9 M, and a little depression of the maximal response in addition to the parallel rightward shift of the concentration‐response curve at a concentration of 10−8 M. Analysis of the data yield a pA2 of 9.2 ± 0.2 (n = 5) and a slope of 1.5 ± 0.2 (n = 5).
In vivo, the oral administration of FR173657 inhibited BK‐induced bronchoconstriction dose‐dependently in guinea‐pigs with an ED50 of 0.075 mg kg−1, but did not inhibit histamine‐induced bronchoconstriction even at 1 mg kg−1. FR173657 also inhibited carrageenin‐induced paw oedema with an ED50 of 6.8 mg kg−1 2 h after the carrageenin injection in rats.
These results show that FR173657 is a potent, selective, and orally active bradykinin B2 receptor antagonist.
Localization of leukaemia inhibitory factor to airway epithelium and its amplification of contractile responses to tachykinins
Authors: Knight Darryl , McKay Karen , Wiggs Barry , Robert Schellenberg R , Bai Tony 
Published: August 2006

In neural tissue, leukaemia inhibitory factor (LIF) is an important trophic cytokine. In this investigation, we determined if LIF was present in human and guinea‐pig airways and examined the role of this cytokine in modulating airway responses to endogenous and exogenous tachykinins as well as muscarinic receptor and β‐adrenoceptor stimulation.
The presence of LIF in both human and guinea‐pig airways was determined by immunohistochemistry. Guinea‐pig tracheal explants were incubated in CRML‐1066 media containing LIF (0.5, 5 or 50 ng ml−1) for periods of 3, 6, 24 and 48 h. Tracheal rings were then transferred to organ baths for measurement of isometric force in response to carbachol, capsaicin, the neurokinin1 (NK1) receptor agonist [Sar9,Met(O2)11]‐substance P (SP), the NK2 receptor agonist neurokinin A (NKA) and isoprenaline.
LIF immunoreactivity was observed primarily in basally situated cells in the airway epithelium of both large and small airways. Less intense immunoreactivity was observed in vascular endothelium and glandular epithelium.
Treatment with LIF (0.5 ng ml−1) for 3 and 6 h significantly increased contractile responses to capsaicin by 42% and 43%, respectively, compared to time controls, whereas higher concentrations of LIF (5 and 50 ng ml−1) enhanced capsaicin‐induced contractions only after 6 h. After 24 h, responses to capsaicin were not significantly different from 0 h control. Contractile responses to capsaicin following exposure to LIF at any concentration for 24 h were not significantly different from relative time control values.
Responses to [Sar9,Met(O2)11]‐SP, carbachol and isoprenaline were not influenced by time in culture or by exposure to LIF for up to 48 h. Contractile responses induced by NKA were not influenced by 3 or 6 h exposure to LIF, but at 24 and 48 h the mean maximum contractile responses to NKA were significantly increased by 33% and 35%, respectively, compared to control.
These results demonstrate that LIF is present in guinea‐pig and human airway epithelium, and modulates airway responses to tachykinins. In the acute setting LIF augments the capsaicin‐induced release of endogenous tachykinins, whilst in the longer term (>24 h), LIF increases airway smooth muscle responses to tachykinins via an NK2 receptor selective mechanism. We conclude that LIF may be an important effector molecule in the response of airways to injury or inflammation.

British Journal of Pharmacology (1997) 120, 883–891; doi:10.1038/sj.bjp.0700965
Visual detection of transport‐P in peptidergic neurones
Authors: Al‐Damluji Saad , Porter Denise , Krsmanovic Lazar Z , Knutson Jay R , Kopin Irwin J 
Published: August 2006

Hypothalamic peptidergic neurones possess an uptake process for amines (transport‐P), for which prazosin is a substrate. It is characterized by a paradoxical increase in the accumulation of [3H]‐prazosin when the concentration of unlabelled prazosin is increased above 10−7 m. This increase is due to activation of a proton‐dependent, vacuolar‐type ATPase‐linked pump that is blocked by tricyclic antidepressants. This study utilized a fluorescence method to detect amine uptake in individual cells.
Prazosin is fluorescent but most of its emission spectrum is in the ultraviolet range. We therefore used an analogue of prazosin in which the furan ring had been substituted with a fluorescent group, BODIPY FL. This compound's emission maximum is in the green part of the visible spectrum.
BODIPY FL prazosin accumulated in immortalised peptidergic neurones and the characteristic emission spectrum of the compound was evident in these cells. Accumulation of BODIPY FL prazosin was saturable and was inhibited by the tricyclic antidepressant desipramine and by unlabelled prazosin. As previously described for prazosin, uptake of BODIPY FL prazosin was blocked by cold temperature and by the organic base chloroquine. Thus, prazosin and BODIPY FL prazosin were accumulated by the same uptake process.
BODIPY FL prazosin accumulated in a granular distribution, which is compatible with storage in intracellular vesicles.
Hypothalamic cells from foetal rats in primary culture also accumulated BODIPY FL prazosin by a desipramine‐sensitive process. Uptake was predominantly in neurones and glial cells did not accumulate the amine.
Fluorescent detection provides visual evidence for amine uptake in peptidergic neurones and should enable detailed study of the distribution of this process in the brain.

British Journal of Pharmacology (1997) 120, 876–882; doi:10.1038/sj.bjp.0700970