Lack of effect of sacral nerve stimulation for incontinence in patients with systemic sclerosis.

AIM: Systemic sclerosis (SSc) is a multisystem disorder of unknown aetiology leading to the deposition of excessive connective tissue in the skin, blood vessels and internal organs. Gastrointestinal involvement occurs in 90% of cases and the prevalence of faecal incontinence (FI) is 38%. This study comprises the largest case series assessing the efficacy of sacral nerve stimulation (SNS) treatment for incontinence in this patient group. METHOD: A retrospective analysis on prospectively collected data was performed on all SSc patients from our two centres who had undergone SNS for FI. RESULTS: Ten female patients of mean age of 54 (37-72) years had temporary SNS performed. The mean duration of FI was 13 (2-25) years. All had passive FI. Each patient had preprocedure anorectal physiology and endoanal ultrasound examinations documenting internal sphincter atrophy/fragmentation or reduced anal resting pressure. Overall there was no statistically significant difference (P = 0.57) in the total Wexner incontinence scores before (mean 15.1 ± 2.6 SD) and during temporary SNS procedures (mean 13.1 ± 3.6 SD). Two patients with a significant improvement went on to have permanent SNS with only one achieving a favourable outcome at 1 year. CONCLUSION: This study showed that SNS failed to reduce episodes of leakage in nine out of 10 patients with systemic sclerosis affected with incontinence.

Novel pathways for glucocorticoid effects on neutrophils in chronic inflammation.

Neutrophils have been implicated in mediating much of the tissue damage associated with chronic inflammatory diseases such as rheumatoid arthritis, where they are involved in destruction of both cartilage and bone. Glucocorticoids are powerful anti-inflammatory agents, often used in the treatment of this autoimmune disease. They exert significant inhibitory effects on neutrophil activation and functions, such as chemotaxis, adhesion, transmigration, apoptosis, oxidative burst, and phagocytosis. The mechanisms by which glucocorticoids exert these effects on neutrophils are unclear. Evidence from studies of inflammation in human subjects and animal models suggests that annexin-I an endogenous, glucocorticoid-induced protein also known as lipocortin-1, has a pivotal role in modulating neutrophil activation, transmigratory, and phagocytic functions. Furthermore, we present evidence for altered neutrophil functions in rheumatoid arthritis that correspond to a significantly reduced capacity of these cells to bind annexin-I. A proposed novel pathway for glucocorticoid actions on neutrophils involving annexin-I could explain the development of chronic neutrophil activation in diseases such as rheumatoid arthritis.

Inhibition of bradykinin-evoked trigeminal nerve stimulation by the non-peptide bradykinin B2 receptor antagonist WIN 64338 in vivo and in vitro.

1. This study investigated the effect of the recently described non-peptide bradykinin B2 receptor antagonist, WIN 64338 ([[4-[[2- [[bis(cyclohexylamino)methylene]amino]-3-(2-naphthalenyl)-1-oxopropyl] amino]phenyl]methyl]tributylphosphoniumchloride monohydrochloride), in experimental models of bradykinin-evoked sensory nerve stimulation. 2. In the rabbit isolated iris sphincter in vitro, bradykinin-evoked contractile responses are mediated via tachykinins released from peripheral endings of the trigeminal sensory nerve. WIN 64338 (1-10 microM) competitively antagonised contractile responses to bradykinin with a pKB estimate of 6.6 +/- 0.1 (n = 11). The antagonism was selective since WIN 64338 (10 microM) did not significantly inhibit submaximal contractile responses to the direct-acting spasmogens substance P (10 nM), neurokinin A (3 nM), substance P methyl ester (10 nM) or senktide (100 nM); nor by sensory non-adrenergic non-cholinergic nerve stimulation evoked by capsaicin (10 microM), or electrical field-stimulation (3, 10, 30 Hz) (P > 0.05; n = 3-11). 3. Topical application of bradykinin to the conjunctiva and to the nasal mucosa of the guinea-pig in vivo causes plasma extravasation predominantly via the release of tachykinins from peripheral endings of the trigeminal nerve. The increases in plasma extravasation (measured by extravasation of Evans blue dye) induced by bradykinin in the guinea-pig conjunctiva (20 nmol) and nasal mucosa (50 nmol) were markedly reduced (by 81 +/- 3% and 69 +/- 5%, respectively) following pretreatment with WIN 64338 (30 nmol kg-1, i.v.) (n = 5-6; P < 0.05), with almost complete inhibition at a higher dose of WIN 64338 (300 nmol kg-1, i.v.; n = 5-6). This inhibition was selective since at 300 nmol kg-1, WIN 64338 did not inhibit plasma extravasation evoked by substance P in the conjunctiva (5 nmol; P > 0.05; n = 6) or in the nasal mucosa (50 nmol; P > 0.05; n = 5). 4. This study demonstrates that WIN 64338 is a selective and competitive bradykinin B2 receptor antagonist and can be useful for analysing bradykinin-evoked trigeminal nerve stimulation both in vitro and in vivo.

Bradykinin B1 receptors in the rabbit urinary bladder: induction of responses, smooth muscle contraction, and phosphatidylinositol hydrolysis.

1. The aim of this study was to analyse the pharmacological characteristics, and second-messenger coupling-mechanisms, of bradykinin B1 receptors in an intact tissue, the rabbit urinary bladder; and to investigate the influence of inhibition of endogenous peptidases on kinin activities. 2. In preparations of rabbit mucosa-free urinary bladder, at 90 min after mounting of the preparations, bradykinin (1 nM-10 microM) evoked contractile responses. In contrast, the B1 receptor-selective agonist [des-Arg9]-BK (10 mM-10 microM) was only weakly active at this time. Contractile responses to [des-Arg9]-BK increased with time of tissue incubation in the organ bath, reaching a maximum after 3 h, when the pD2 estimates were 6.4 +/- 0.3 for bradykinin, and 6.9 +/- 0.2 for [des-Arg9]-BK. 3. Once stabilized, responses to [des-Arg9]-BK in the bladder were competitively antagonized by the B1 receptor-selective antagonists [Leu8,des-Arg9]-BK and D-Arg-[Hyp3,Thi5,D-Tic7,Oic8,des-Arg9]-BK ([des-Arg10]-Hoe140) (pKB estimates were 6.1 +/- 0.1 and 7.1 +/- 0.1, respectively; n = 17-21), but responses were unaffected by the B2 receptor-selective antagonist D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]-BK (Hoe140) (100 nM; n = 4). Contractile responses to bradykinin itself were partially, but significantly, inhibited by the B1 receptor-selective antagonist, [Leu8,des-Arg9]-BK (10 microM) (P < 0.05), or by the B2 receptor-selective antagonist Hoe140 (100 nM) (P < 0.005) alone, and were largely blocked by a combination of the two antagonists (P < 0.0001). 4. The combined presence of the carboxypeptidase inhibitor DL-2-mercaptomethyl-3-guanidinoethylthiopropanoicacid (mergetpa; 10 microM), the neutral endopeptidase inhibitor, phosphoramidon (1 microM),and the angiotensin-converting enzyme inhibitor, enalaprilat (1 microM) increased the potency of bradykinin17 fold (P<0.001), but that of [des-Argl-BK was unchanged (P>0.05): pD2 estimates were 7.6 +/- 0.1 and 6.8 +/- 0.1 for bradykinin and [des-Argl-BK, respectively, in treated preparations. In the presence of peptidase inhibitors, the affinities of the antagonists [Leu8,des-Arg9]-BK and [des-Arg'j-Hoel4O were unchanged as compared with those determined in the absence of peptidase inhibitors (P> 0.05).[Leu8,des-Argj-BK inhibited responses to bradykinin under these conditions (n = 4).5. In endothelium-denuded preparations of the rabbit isolated aorta, an archetypal B1 receptor preparation,contractile responses to the B1 receptor-selective agonist [des-Argl-BK (10nM- 1O0 AM) (and to bradykinin) increased progressively with time of tissue incubation; and [des-Argl-BK responses were completely antagonized by the B. receptor antagonist [Leu8,des-Arg9]-BK (pKB 6.3 +/- 0.2; n = 13).6. In experiments measuring stimulation of hydrolysis of phosphatidylinositol in rabbit urinary bladder,[des-Argl-BK (10 microM- 1 mM), and bradykinin (100 microM) significantly increased accumulation of inositol phosphates (P<0.0001). The increase in accumulation of inositol phosphates evoked by [des-Arg9]-BK(10 microM - 1 mM) was significantly inhibited by [des-Arg'j-Hoe 140 (10 microM) (P <0.01).7. We conclude that in the mucosa-free rabbit urinary bladder, [des-Argl-BK evokes contraction largely via activation of B1 receptors which have similar properties, including time-dependent induction,to B1 receptors in the rabbit isolated aorta. Bradykinin evokes contraction via stimulation of both B1 and B2 receptors, but does not require conversion by peptidases in order to activate B1 receptors. We demonstrate, for the first time, B1 receptor-coupling to phosphatidylinositol hydrolysis in an intact tissue preparation.

Bradykinin B2 receptors and coupling mechanisms in the smooth muscle of the guinea-pig taenia caeci.

1. In the smooth muscle of the guinea-pig taenia caeci, bradykinin produces a relaxation followed by a contraction. In the presence of hexamethonium and guanethidine, both these phases of the response were insensitive to tetrodotoxin (100 nM), omega-conotoxin GVIA (100 nM) and ibuprofen (1 microM), suggesting that they are due to a direct action on the smooth muscle. 2. The B1 receptor-selective agonist, [des-Arg9]-BK (1-100 microM), was inactive in the taenia caeci, and the B1 receptor-selective antagonist, [Leu8,des-Arg9]-BK (1-10 microM), did not inhibit either phase of the bradykinin-induced response. The B2 receptor-selective antagonist, D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]-BK (Hoe 140) (30-300 nM), inhibited both the bradykinin-induced relaxation and contraction with a similar affinity (apparent pKB estimates of 8.5 +/- 0.1 and 8.4 +/- 0.1 respectively). 3. In a depolarizing high-K(+)-solution, bradykinin produced concentration-related contractions, though of diminished magnitude; but no relaxation was observed in such media. In Krebs solution, the Ca(2+)-activated K(+)-channel blocker, apamin (10 nM), abolished relaxant responses. These observations suggest that contraction results both from membrane potential-dependent, and membrane potential-independent, mechanisms; whereas relaxant responses result entirely from membrane potential-dependent mechanisms. Contractile responses obtained in the high K(+)-solution were inhibited by D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]-BK with an apparent pKB value of 8.4 +/- 0.1. 4. In a Ca(2+)-free, EGTA-containing medium, relatively high concentrations of bradykinin (> 100 nM) produced transient contractions, suggesting that a component of the contractile response results from release of Ca2+ from an intracellular store. This intracellular Ca2+ store could be refilled in the presence of extracellular Ca2+. The B, receptor antagonist, [Leu8,des-Argj-BK (10 micro M), did not inhibit this bradykinin-induced contraction, whereas the B2 receptor antagonist, D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]-BK(100 nM) markedly attenuated it (P<0.001; n = 6).5. Bradykinin (10 nM- 100 micro M) significantly elevated tissue levels of total [3H]-inositol phosphates in the presence of Li?, after incubation with myo-[3H]-inositol. The B, receptor-selective agonist, [des-Argl-BK(100IM) did not stimulate [3H]-inositol phosphate formation, and the B, receptor-selective antagonist,[Leu8,des-Argl-BK, did not inhibit the formation of [3H]-inositol phosphates in response to a submaximal concentration of bradykinin (1I0 1M; P> 0.05). Two B2 receptor antagonists, D-Arg-[Hyp3,DPhe7]-BK and D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]-BK, inhibited bradykinin-induced accumulation of total[3H]-inositol phosphates with apparent pKB estimates of 5.4 +/0 0.3 and 8.4 +/- 0.1, respectively.6. These data suggest that in the guinea-pig taenia caeci, the five aspects of the action of bradykinin studied (the relaxant and the contractile elements of the biphasic mechanical response, the contractile response in a depolarizing high-K' solution medium and zero-Ca2+ media, and stimulation of phosphatidylinositol turnover), all result from activation of B2 receptors. A possible causal relationship is suggested between these B2 receptor-mediated membrane potential-dependent, and -independent events,and their roles in excitation contraction coupling.