Evaluation of DeGIR registry data on endovascular treatment of cerebral vasospasm in Germany 2018-2021: an overview of the current care situation

BACKGROUND

Evaluation of endovascular therapies for cerebral vasospasm (CVS) documented in the DeGIR registry from 2018-2021 to analyse the current clinical care situation in Germany.

METHODS

Retrospective analysis of the clinical and procedural data on endovascular spasm therapies (EST) documented anonymously in the DeGIR registry. We analysed: pre-interventional findings of CTP and consciousness; radiation dose applied, interventional-technical parameters (local medication, devices, angiographic result), post-interventional symptoms, complications and mortality.

RESULTS

3584 patients received a total of 7628 EST (median age/patient: 53 [range: 13-100, IQR: 44-60], 68.2 % women) in 91 (2018), 92 (2019), 100 (2020) and 98 (2021) centres; 5388 (70.6 %) anterior circulation and 378 (5 %) posterior circulation (both involved in 1862 cases [24.4 %]). EST was performed once in 2125 cases (27.9 %), with a mean of 2.1 EST/patient. In 7476 times, purely medicated EST were carried out (nimodipine: 6835, papaverine: 401, nitroglycerin: 62, other drug not specified: 239; combinations: 90). Microcatheter infusions were documented in 1132 times (14.8 %). Balloon angioplasty (BA) (additional) was performed in 756 EST (9.9 %), other mechanical recanalisations in 154 cases (2 %) and stenting in 176 of the EST (2.3 %). The median dose area product during ET was 4069 cGycm² (drug: 4002/[+]BA: 8003 [p < 0.001]). At least 1 complication occurred in 95 of all procedures (1.2 %) (drug: 1.1 %/[+]BA: 4.2 % [p < 0.001]). Mortality associated with EST was 0.2 % (n = 18). After EST, overall improvement or elimination of CVS was found in 94.2 % of cases (drug: 93.8 %/[+]BA: 98.1 % [p < 0.001]). In a comparison of the locally applied drugs, papaverine eliminated CVS more frequently than nimodipine (p = 0.001).

CONCLUSION

EST have a moderate radiation exposure and can be performed with few complications. Purely medicated EST are predominantly performed, especially with nimodipine. With (additional) BA, radiation exposure, complication rates and angiographic results are higher or better. When considering drug EST alone, there is evidence for an advantage of papaverine over nimodipine, but a different group size has to be taken into account. In the analysis of EST, the DeGIR registry data are suitable for answering more specific questions, especially due to the large number of cases; for this purpose, further subgroupings should be sought in the data documentation.

KEY POINTS

· In Germany, there are currently no guidelines for the endovascular treatment of cerebral vasospasm following spontaneous subarachnoid hemorrhage.. · In addition to oral nimodipine administration endovascular therapy is used to treat cerebral vasospasm in most hospitals.. · This is the first systematic evaluation of nationwide registry data on endovascular treatment of cerebral vasopasm in Germany.. · This real-world data shows that endovascular treatment for cerebral vasospasm has a moderate radiation exposure and can be performed with few complications overall. With (additional) balloon angioplasty, radiation exposure, complication rates and angiographic therapy results are higher or better..

CITATION FORMAT

· Neumann A, Weber W, Küchler J et al. Evaluation of DeGIR registry data on endovascular treatment of cerebral vasospasm in Germany 2018-2021: an overview of the current care situation. Fortschr Röntgenstr 2023; 195: 1018 - 1026.

Demonstration of ameliorating effect of papaverine in sepsis-induced acute lung injury on rat model through radiology and histology

BACKGROUND

Our target was to show the role of high mobility group box-1/receptor for (HMGB1/RAGE) interaction in feces intraperitoneal injection procedure (FIP)-induced acute lung injury (ALI) pathophysiology, to investigate the effect of papaverine on RAGE associated NF-κB pathway by determining the level of soluble RAGE (sRAGE) and HMGB1, and to support this hypothesis by evaluating inflammatory biochemical, oxidative stress markers, Hounsfield unit (HU) value in computed tomography (CT), and histo-pathological results.

METHODS

FIP was performed on 37 Wistar rats for creating a sepsis-induced ALI model. The animals were assigned into four groups as follows: Normal control (no treatment), placebo (FIP and saline), and receiving 20 mg/kg and 40 mg/kg per day papaverine. Twenty h after FIP, CT examination was performed for all animals, and HU value of the lung parenchyma was measured. The plasma levels of tumor necrosis factor (TNF)-α, HMGB1, sRAGE, C-reactive protein (CRP) and malondialdehyde (MDA), and lactic acid (LA) were determined and PaO2 and PaCO2 were measured from arterial blood sample. Lung damage was assessed by histopathological.

RESULTS

TNF-, IL-6, CRP, HMGB1, MDA, LA levels, histopathologic scores, and HU values of CT were significantly increased and sRAGE levels were decreased in the saline-treated group against normal group (all P<0.05). Papaverine significantly reversed all results regardless of the dose (all P<0.05) and demonstrated inhibition of HMGB1/RAGE interaction through increasing sRAGE levels and suppresses the pro-inflammatory cytokines.

CONCLUSION

We concluded that papaverine has ameliorating effects in rat model of ALI.

Drotaverine Inhibitor of PDE4: Reverses the Streptozotocin Induced Alzheimer's Disease in Mice

Alzheimer's disease (AD) is a progressive neurodegenerative disease associated with decline in memory and cognitive impairments. Phosphodiesterase IV (PDE4) protein, an intracellular cAMP levels regulator, when inhibited act as potent neuroprotective agents by virtue of ceasing the activity of Pro-inflammatory mediators. The complexity of AD etiology has ever since compelled the researchers to discover multifunctional compounds to combat the AD and neurodegeneration. The aim of this study was to probe into role of drotaverine a PDE4 inhibitor in the management of AD. Albino mice were divided into seven groups (n = 10). Group 1 control group received carboxy methyl cellulose (CMC 1 mL/kg), group II diseased group treated with streptozotocin (STZ 3 mg/kg) by intracerebroventricular (ICV) route, group III administered standard drug Piracetam 200 mg/kg and groups IV-VII were given drotaverine (10, 20, 40, and 80 mg/kg i/p respectively). Groups II-VII were given STZ (3 mg/kg, ICV) on 1st and 3rd day of treatment to induce AD. All the groups were given their respective treatments for 23 days. Improvement in learning and memory was evaluated by using behavioral tests like open field test, elevated plus maze test, Morris water maze test and passive avoidance test. Furthermore, brain levels of biochemical markers of oxidative stress, neurotransmitters, β-amyloid and tau protein were also measured. Drotaverine showed statistically significant dose dependent improvement in behavioral and biochemical markers of AD: the maximum response was achieved at a dose level of 80 mg/kg. The Study concluded that drotaverine ameliorates cognitive impairment and as well as exhibited modulated the brain levels of neurotransmitters.

Papaverine ameliorates prenatal alcohol-induced experimental attention deficit hyperactivity disorder by regulating neuronal function, inflammation, and oxidative stress

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder with complex aetiology and phenotypes. Phosphodiesterase10A (PDE10A) has been shown to provide benefits in various brain conditions. We investigated the role of papaverine, a selective PDE10A inhibitor on core phenotypes in prenatal alcohol exposure (PAE) model of ADHD. In order to identify probable mechanisms involved, the effects on several protein markers of neuronal function such as, neuronal survival-BDNF, neuronal transcription factor-pCREB, brain inflammation (IL-6, IL-10, and TNF-α), and brain oxidative stress (TBARS and GSH) were studied in frontal cortex, cerebellum, and striatum. PAE resulting hyper-locomotion, inattention, and anxiety were studied by the use of open-field, y-maze, and elevated plus maze, respectively. Administration of papaverine (15/30 mg kg-1 ) to PAE group of animals resulted in amelioration of hyperactivity, inattention, and anxiety. Also, papaverine resulted in significant increase of the levels in BDNF, pCREB, IL-10, and GSH along with significant decrease of TNF-α, IL-6, and TBARS in different brain areas of PAE group. Papaverine, a selective PDE10A inhibitor rectified behavioural phenotypes associated with ADHD, possibly by altering the protein markers associated with neuronal survival, neuronal transcription factor, brain inflammation, and brain oxidative stress. Implicating PDE10A as a possible target for furthering our understanding of ADHD phenotypes.

Papaverine Perfusion via the Aortic Root before Heart Re-beating Alleviates Myocardial Injury after Heart Valve Replacement

AIM

Myocardial injury is inevitable during cardiac surgical procedures and reducing myocardial injury in patients with CPB surgery is the focus of current research. Papaverine is accepted as an ideal coronary vasodilator. This study was to estimate the effect of papaverine perfusion via the aortic root before heart re-beating on patients undergoing heart valve replacement.

METHODS

All the patients enrolled in this study were admitted during 2013-2015. The basic clinical characteristics of the patients preoperative, intraoperative, and postoperative were compared. The immunochemistry assays and enzyme-linked immunosorbent assay (ELISA) were performed to assess the serum biomarkers. Western blot and immunohistochemistry (IHC) were undertaken to detect the expression of associated proteins.

RESULTS

Patients receiving papaverine perfusion via the aortic root before heart re-beating during heart valve replacement surgery under CPB showed less extracorporeal circulation time and CPB time, higher automatic heartbeat recovery rate, less mechanical ventilation time, shorter ICU and in-hospital stay, less leak of cTnI and CK-MB, and weaker inflammatory response than the patients in control group. In addition, the protein expression of IL-6/8/10 and TNF-α was reduced by the perfusion of papaverine. The IHC staining for NFκB was depressed in papaverine group.

CONCLUSION

Papaverine perfusion presented positive effect during valve replacement; this cardioprotective effect may be associated with inhibition of inflammatory response and NF-κB. These findings provided new clues for reduction of myocardial injury during cardiac surgery.

Anticancer effects of a non-narcotic opium alkaloid medicine, papaverine, in human glioblastoma cells

The interaction between high-mobility group box 1 protein (HMGB1) and receptor for advanced glycation end products (RAGE) is important for tumor cell growth. We investigated the tumor biological effects of HMGB1 and RAGE interaction. Previously, we identified an inhibitor of HMGB1/RAGE interaction, papaverine (a non-narcotic opium alkaloid), using a unique drug design system and drug repositioning approach. In the present study, we examined the anticancer effects of papaverine in human glioblastoma (GBM) temozolomide (TMZ; as a first-line anticancer medicine)-sensitive U87MG and TMZ-resistant T98G cells. HMGB1 supplementation in the culture medium promoted tumor cell growth in T98G cells, and this effect was canceled by papaverine. In addition, papaverine in T98G cells suppressed cancer cell migration. As an HMGB1/RAGE inhibitor, papaverine also significantly inhibited cell proliferation in U87MG and T98G cells. The effects of papaverine were evaluated in vivo in a U87MG xenograft mouse model by determining tumor growth delay. The results indicate that papaverine, a smooth muscle relaxant, is a potential anticancer drug that may be useful in GBM chemotherapy.

Papaverine identified as an inhibitor of high mobility group box 1/receptor for advanced glycation end-products interaction suppresses high mobility group box 1-mediated inflammatory responses

The interaction of high mobility group box 1 (HMGB1), which is secreted from immune and dying cells during cellular infection and injury, and receptor for advanced glycation end-products (RAGE) appears to be critical for acute and chronic inflammatory disorders. Here we designed a unique cyclic β-hairpin peptide (Pepb2), which mimics the predicted RAGE-binding domain of HMGB1. Pepb2 competitively inhibited HMGB1/RAGE interaction. We then identified papaverine as a Pepb2 mimetic by in silico 3D-structural similarity screening from the DrugBank library. Papaverine was found to directly inhibit HMGB1/RAGE interaction. It also suppressed the HMGB1-mediated production of pro-inflammatory cytokines, IL-6 and TNF-α, in mouse macrophage-like RAW264.7 cells and bone marrow-derived macrophages. In addition, papaverine attenuated mortality in cecal ligation puncture-induced sepsis model mice. Taken together, these findings indicate that papaverine could become a useful therapeutic against HMGB1/RAGE-mediated sepsis and other inflammatory diseases.

Neuromuscular electrical stimulation as an adjunctive therapy to drotaverine hydrochloride for treating patients with diarrhea-predominant irritable bowel syndrome: A retrospective study

This retrospective study investigated the effectiveness and safety of neuromuscular electrical stimulation (NMES) as an adjunctive therapy to drotaverine hydrochloride (DHC) in patients with diarrhea-predominant irritable bowel syndrome (BP-IBS).A total of 108 patient cases with BP-IBS were included in this study. Of these, 54 cases were assigned to a treatment group and received NMES and DHC, whereas the other 54 subjects were assigned to a control group and underwent DHC alone. All patients were treated for a total of 4 weeks. Primary outcomes were measured by the visual analog scale (VAS), and average weekly stool frequency. Secondary outcome was measured by the Bristol scale. In addition, adverse events were documented. All outcome measurements were analyzed before and after 4-week treatment.Patients in the treatment group did not show better effectiveness in VAS (P = .14), and average weekly stool frequency (P = .42), as well as the Bristol scale (P = .71), compared with the patients in the control group. Moreover, no significant differences in adverse events were found between 2 groups.The results of this study showed that NMES as an adjunctive therapy to DHC may be not efficacious for patients with BP-IBS after 4-week treatment.

The protective effect of Papaverine and Alprostadil in rat testes after ischemia and reperfusion injury

OBJECTIVE

To investigate the effect of papaverine and alprostadil on testicular torsion-detorsion injury in rats.

MATERIALS AND METHODS

A total of 40 male Wistar-Albino rats were used in this study. Four hours of right testicular torsion was applied to each group, excluding sham operated group. The torsion-detorsion (T/D), T/D + papaverine and T/D + alprostadil groups received saline, papaverine and alprostadil at the same time as surgical detorsion, respectively. At 14 days after the surgical detorsion, ischaemic changes and the degree of damage were evaluated with Cosentino scoring and the Johnson tubular biopsy score (JTBS).

RESULTS

JTBS was determined as 8.8±2.7 in the Sham group, 5.08±1.9 in the T/ D+papaverine group, 5.29±2.3 in the T/D +alprostadil group and 2.86±1.9 in the TD group. The JTBS was determined to be statistically significantly high in both the T/D + papaverine group and the T/D + alprostadil group compared to the T/D group (p=0.01, p=0.009). In the T/D + papaverine group, 3 (43 %) testes were classified as Cosentino 2, 3 (43%) as Cosentino 3 and 1 (14 %) as Cosentino 4. In the T/D +alprostadil group, 5 (50 %) testes were classified as Cosentino 2, 3 (30 %) as Cosentino 3 and 2 (20%) as Cosentino 4.

CONCLUSION

The present study indicated that spermatic cord administration of alprostadil and papaverine showed a protective effect against ischemia/reperfusion injury after right-side testes torsion and histological changes were decreased after testicular ischemia reperfusion injury.

Intracorporeal Papaverine Injection in Androgen Deprived Men

The intracorporeal injection of papaverine (ICP) is now a well recognized therapeutic option in the management of impotence. The current treatment of advanced prostatic carcinoma causes erectile failure. Although intracorporeal papaverine can induce erections in these men, libido is also reduced so that the role of ICP is limited to those men complying with the wishes of a highly motivated partner.

Randomized controlled study of efficacy and safety of drotaverine hydrochloride in patients with irritable bowel syndrome

BACKGROUND

This study aimed to assess the efficacy and safety of drotaverine hydrochloride (DHC) in Chinese patients with irritable bowel syndrome (IBS).

METHODS

Totally, 144 patients with IBS were included and randomly divided into treatment group and placebo group in a 1:1 ratio. Patients received either DHC or placebo 80-mg tablet, 3 times daily for a total of 4 weeks. The primary outcome included abdominal pain, measured by the visual analog scale (VAS), and weekly stool frequency. The secondary outcomes were measured by the Bristol scale, and the 36-item short form health survey (SF-36), as well as the adverse events recorded during the treatment period. All those outcomes were measured at the end of 4-week treatment.

RESULTS

The total and different types of IBS in VAS, stool frequency, and Bristol score were significantly better in the treatment group than those in the placebo group at the end of 4-week treatment. However, no significant difference was found in quality of life, measured by SF-36 scale between 2 groups. Additionally, no serious and significant differences in adverse events were found in and between both groups.

CONCLUSION

The findings suggest that DHC has promising efficacy to enhance symptoms of IBS in Chinese population.

Phosphodiesterase-4 inhibition restored hippocampal long term potentiation after primary blast

Due to recent military conflicts and terrorist attacks, blast-induced traumatic brain injury (bTBI) presents a health concern for military and civilian personnel alike. Although secondary blast (penetrating injury) and tertiary blast (inertia-driven brain deformation) are known to be injurious, the effects of primary blast caused by the supersonic shock wave interacting with the skull and brain remain debated. Our group previously reported that in vitro primary blast exposure reduced long-term potentiation (LTP), the electrophysiological correlate of learning and memory, in rat organotypic hippocampal slice cultures (OHSCs) and that primary blast affects key proteins governing LTP. Recent studies have investigated phosphodiesterase-4 (PDE4) inhibition as a therapeutic strategy for reducing LTP deficits following inertia-driven TBI. We investigated the therapeutic potential of PDE4 inhibitors, specifically roflumilast, to ameliorate primary blast-induced deficits in LTP. We found that roflumilast at concentrations of 1nM or greater prevented deficits in neuronal plasticity measured 24h post-injury. We also observed a therapeutic window of at least 6h, but <23h. Additionally, we investigated molecular mechanisms that could elucidate this therapeutic effect. Roflumilast treatment (1nM delivered 6h post-injury) significantly increased total AMPA glutamate receptor 1 (GluR1) subunit expression, phosphorylation of the GluR1 subunit at the serine-831 site, and phosphorylation of stargazin at the serine-239/240 site upon LTP induction, measured 24h following injury. Roflumilast treatment significantly increased PSD-95 regardless of LTP induction. These findings indicate that further investigation into the translation of PDE4 inhibition as a therapy following bTBI is warranted.

[COMPLEX TREATMENT OF PURULENT-NECROTIC COMPLICATIONS IN THE PATIENTS, SUFFERING DIABETIC FOOT SYNDROME, USING NEGATIVE TRESSURE AND CAPICOR PREPARATION]

The comparative analysis data were presented, concerning the results of complex treatment of 28 patients, suffering ischemic-gangrenous form of the diabetic foot syndrome, developing on background of chronic ischemia of the lower extremities stage IV. In 14 patients (main group) a routine complex of the treatment measures was added by application of an active pressure (negative pressure wound therapy - NPWT) and a capicor preparation; 14 patients (the comparison group) were treated in accordance to routine scheme. In accordance to the comparative analysis data, in patients of the main group the wound surface sarea have kept reducing in twice more rapid, than in a comparison group, the wounds healing was achieved in 94% patients, duration of the patients’ stationary stay have reduced by (5.2 ± 1.4) days.

Papaverine for Ischemia Following Peripheral Arterial Catheterization in Neonates

11 Extremely low birth weight neonates who developed skin discoloration after peripheral arterial catheterization were given intra-arterial papaverine before the removal of arterial line. The skin color turned normal in all these neonates and none developed residual damage. In 3 neonates who could not receive papaverine, one developed gangrene of fingers.

Antioxidant therapy in the elderly with tinnitus

INTRODUCTION

Several approaches have been tried for the treatment of tinnitus, from cognitive-behavioral therapies and sound enrichment to medication. In this context, antioxidants, widely used in numerous areas of medicine, appear to represent a promising approach for the control of this symptom, which often is poorly controlled.

OBJECTIVE

To evaluate the effects of antioxidant therapy for tinnitus in a group of elderly patients.

METHODS

Prospective, randomized, double-blinded, placebo-controlled clinical trial. The sample consisted of 58 subjects aged 60 years or older, with a complaint of tinnitus associated with sensorineural hearing loss. These individuals completed the Tinnitus Handicap Inventory (THI) questionnaire before and after six months of therapy. The treatment regimens were: Ginkgo biloba dry extract (120mg/day), α-lipoic acid (60mg/day)+vitamin C (600mg/day), papaverine hydrochloride (100mg/day)+vitamin E (400mg/day), and placebo.

RESULTS

There was no statistically significant difference between THI by degree (p=0.441) and by score (p=0.848) before and after treatment.

CONCLUSION

There was no benefit from the use of antioxidant agents for tinnitus in this sample.

[APPLICATION OF LARGE SUBCUTANEOUS VEIN AS MATERIAL FOR DISTAL SHUNTING IN CRITICAL ISCHEMIA OF THE LOWER EXTREMITY TISSUES]

While performing autologous reconstruction of distal arteries in 24 patients in chronic critical ischemia of the lower extremity tissues the method of a large subcutaneous vein mobilization, using a ring-like desobliterator,was applied. This have permitted to reduce the procedure traumaticity, comparing with a standard method. Additional application of pharmacological vasodilatation of venous transplant have permitted to avoid the risk, connected with impact of hydraulic vasodilatation on the venous wall functional state.

Non-occlusive mesenteric ischemia after splenic metastasectomy for small-cell lung cancer

A 68-year-old man presented with severe abdominal pain. Seven months earlier, he had received systemic chemotherapy for small-cell lung cancer with solitary metastasis to the spleen, followed by splenectomy. Abdominal computed tomography and abdominal arterial angiography showed diffuse ischemia of the mesenteric artery without apparent occlusion. The patient also suffered from septicemia caused by Enterococcus faecium. Therefore, a diagnosis of non-occlusive mesenteric ischemia (NOMI) induced by septicemia was supposed. Although treatment with antibiotics and papaverine hydrochloride was administered and the necrotic tissue in the intestinal tract was resected, the patient died. Physicians should be aware that patients undergoing splenectomy are likely to be affected by septicemia, which may subsequently induce NOMI.

[Efficiency of etiologic correction of concomitant ascaridosis in the complex treatment of chronic pancreatitis]

The of antihelmintic preparation albendazole using in the complex treatment of patients with chronic pancreatitis with the concomitant ascaridosis was promote regression of clinical demonstration of basic and concomitant diseases (P < 0.05). Options of coprogram and the structural state of pancreas from data of ultrasonography in marks by Marseille-Cambridge classification of chronic pancreatitis, after the conducted treatment became the better (P < 0.05), that established expedience of the use of albendazole in complex treatment of patients with a chronic pancreatitis with a concomitant ascaridosis.

An atypical presentation of testicular torsion: a case report

Testicular torsion is an emergent condition requiring prompt surgical intervention to avoid permanent testicular compromise and death. As its symptoms overlap with other disease processes, diagnosis is sometimes difficult. When considering the presenting symptoms, one must be careful not to ignore unusual causes of torsion and misdiagnose the patient. In this case report we describe an unusual etiology of testicular torsion (traumatic) with an atypical patient presentation (mildly painful) which presented many obstacles before proper diagnosis and treatment.

[Nutricional support in the complex treatment of a patient with esophageal spasm]

In the presented clinical case the theme of the need for an integrated therapeutic intervention has been disclosed, including nutritional support on the various links of the pathogenesis of esophagospasm to the effectiveness of the patient's treatment.

Pharmacological explanation for the medicinal use of Juniperus excelsa in hyperactive gastrointestinal and respiratory disorders

Crude extract of Juniperus excelsa (JeExt), which tested positive for the presence of anthraquinone, flavonoids, saponins, sterols, terpenes and tannin, exhibited a protective effect against castor oil-induced diarrhoea in mice at 100-1000 mg/kg. In rabbit jejunum preparations, JeExt (0.01-1.0 mg/mL) caused relaxation of spontaneous and K(+) (80 mM)-induced contractions at similar concentrations to papaverine, whereas verapamil was relatively more potent against K(+). JeExt (0.03-0.3 mg/mL) shifted Ca(2+) concentration-response curves to the right, like papaverine or verapamil. JeExt (0.003-0.01 mg/mL) caused a leftward shift of isoprenaline-induced inhibitory concentration-response curves, similar to papaverine. JeExt (1.0-30 mg/kg) caused suppression of carbachol (CCh, 100 μg/kg)-induced increase in inspiratory pressure of anaesthetized rats. In guinea-pig trachea, JeExt (0.001-3.0 mg/mL) relaxed CCh (1 μM)- and high K(+)-induced contractions and shifted isoprenaline-induced inhibitory curves to the left. This study suggests that Juniperus excelsa possibly exhibits a combination of Ca(2+) antagonist and phosphodiesterase inhibitory effects, which provides a pharmacological basis for its traditional use in disorders of gut and airways hyperactivity, such as diarrhoea, colic and asthma.

Phosphodiesterase 10A upregulation contributes to pulmonary vascular remodeling

Phosphodiesterases (PDEs) modulate the cellular proliferation involved in the pathophysiology of pulmonary hypertension (PH) by hydrolyzing cAMP and cGMP. The present study was designed to determine whether any of the recently identified PDEs (PDE7-PDE11) contribute to progressive pulmonary vascular remodeling in PH. All in vitro experiments were performed with lung tissue or pulmonary arterial smooth muscle cells (PASMCs) obtained from control rats or monocrotaline (MCT)-induced pulmonary hypertensive (MCT-PH) rats, and we examined the effects of the PDE10 inhibitor papaverine (Pap) and specific small interfering RNA (siRNA). In addition, papaverine was administrated to MCT-induced PH rats from day 21 to day 35 by continuous intravenous infusion to examine the in vivo effects of PDE10A inhibition. We found that PDE10A was predominantly present in the lung vasculature, and the mRNA, protein, and activity levels of PDE10A were all significantly increased in MCT PASMCs compared with control PASMCs. Papaverine and PDE10A siRNA induced an accumulation of intracellular cAMP, activated cAMP response element binding protein and attenuated PASMC proliferation. Intravenous infusion of papaverine in MCT-PH rats resulted in a 40%-50% attenuation of the effects on pulmonary hypertensive hemodynamic parameters and pulmonary vascular remodeling. The present study is the first to demonstrate a central role of PDE10A in progressive pulmonary vascular remodeling, and the results suggest a novel therapeutic approach for the treatment of PH.

Preparation and characterization of papaverine-loaded poly[(r)-3-hydroxybutyrate] membranes to be used in the prevention of vasospasm

The objective of this study is the preparation and characterization of poly[(R)-3-hydroxybutyrate] (PHB) membrane loaded with a vasodialative agent (i.e., papaverine hydrochloride) as a blood vessel coverage strip to be used in the prevention of undesired vascular vasospasm. Papaverine-loaded PHB membranes were especially designed to act locally and provide an efficient, long term, and sustained prevention of vasospasm at the site of the newly created vascular anastomosis without any systemic vasodilation effect of the papaverine, which may be life-threatening for the patient. The membranes were prepared by gelation of PHB followed by solvent casting. PHB membranes were characterized in terms of morphology, chemical structure, swelling behavior, in vitro drug release, degradation, and blood compatibility studies as in vitro coagulation tests. Activated partial thromboplastin time, prothrombin time, and fibrinogen concentration were measured by blood coagulation assays. Investigated and evaluated parameters for in vitro drug release, degradation, and in vitro coagulation studies were the concentration of PHB and drug content. Similar effective parameters were used for swelling behavior studies (i.e., concentration of PHB and drug content). Drug release, swelling behavior, degradation, and in vitro coagulation of the membranes were found to be influenced by these parameters. Obtained results showed that papaverine-loaded PHB membranes provide an efficient and advantegous means for the prevention of vasospasm during vascular anastomosis as a local application.

Vasopressin as adjunct vasopressor for vasodilatory shock due to non-occlusive mesenteric ischemia

We present the case of an 83-year-old patient who underwent cardiac surgery and developed postoperative non-occlusive mesenteric ischemia (NOMI), which was treated with a local intra-arterial papaverine and prostaglandin E1 infusion. After successful mesenteric reperfusion, a multiple organ dysfunction syndrome with severe cardiovascular failure developed. High norepinephrine dosages (1.09 microg/kg body weight/min) and catecholamine-related complications (tachycardiac atrial fibrillation) required initiation of supplementary argininevasopressin (AVP) infusion (4 U/h). AVP stabilized vasodilatory shock, ensured adequate gut perfusion pressure and had no adverse clinical or angiographic effects on restitution of gut integrity. In conclusion, after reperfusion of NOMI in this patient, adjunct AVP therapy combined with local vasodilator infusion was beneficial as a potentially life-saving vasopressor.

Sudden hearing loss: a ten-year outpatient experience

The aim of this study was to determine the effects of various treatment modalities employed for patients with sudden sensorineural hearing loss (SHL). We retrospectively evaluated the records of patients treated in the sudden hearing loss section of the Otolaryngology Department at Clinic Hospital, School of Medicine, University of São Paulo, Brazil, between 1996 and 2006. Our study included patients with SHL of sudden onset (occurring over a 72-hour period) at equal to or greater than 30 dB at three consecutive frequencies. We divided patients into five groups by profile and treated them with dextran, dexamethasone, acyclovir, nicotinic acid, and papaverine hydrochloride (with or without vitamin A). We performed audiometry at baseline and on days 30, 90, 120, and 180 of treatment. We determined outcome as the difference between day-0 and day-180 pure-tone averages (PTAs). Among the 139 patients evaluated, baseline PTA was similar in all groups. We observed significant improvements in PTAs after 180 days of treatment and noted a significant linear correlation between time from SHL onset to initial visit and recovery. However, no significant difference was evident among the treatment groups. In the treatment of SHL, dextran provided no more benefit than did dexamethasone or acyclovir. Earlier initiation of treatment improves the prognosis for patients with SHL.

Use of intra-arterial papaverine for severe arterial spasm during radial cardiac catheterization

Coronary angiography and intervention can be performed safely using the radial artery. However, arterial spasm is often encountered and usually amenable to nitrate/verapamil therapy. Rarely, surgical intervention is required to remove catheters and wires. Intra-arterial papavarine can be used to treat severe radial artery spasm and prevent the need for urgent surgical intervention.

Papaverine solution improves preservation of saphenous vein grafts used during cardiac surgery

The purpose of this study was to assess the viability and dilator response of the saphenous vein segments harvested during cardiac surgery. The saphenous veins were incubated with either normal saline (group A) or papaverine solutions (group B). The viability of saphenous vein endothelial cells was assessed by counting the number of total cells. Maximal endothelium-dependent vasodilator response to acetylcholine was also investigated. Cell viability of vein samples was decreased after 4 hours of incubation with normal saline (34 +/- 6.5%) as compared to solution containing papaverine (92 +/- 3.7%). By 24 hours, the viabilities of the endothelial cells incubated with saline and papaverine solutions were 22 +/- 4.5% and 87 +/- 5%, respectively.There was significant difference in vasodilatation responses to acetylcholine between saline-incubated and papaverine-incubated groups. By 4 hours of incubation, the relaxation response to acetylcholine significantly deteriorated in group A when compared to the initial value (P < 0.001). Furthermore, the decrease in this vasorelaxation response has also continued throughout the observation period and the values obtained by 24 hours were observed to be significantly lower than those obtained at the end of 4 hours (P < 0.01). In contrast, although a decrease was noticed in group B over time, this decrease was not statistically significant (P, not significant). We thus conclude that the use of papaverine solution improves endothelial cell viability and is associated with preservation of the maximal endothelial-dependent vasodilator response of a vein segment.

Use of a papaverine solution in peripheral arterial lines

ARTERIAL VASCULAR ACCESS IS often essential to the management of critically ill neonates. If umbilical artery access cannot be obtained or is otherwise contraindicated, peripheral vascular access becomes necessary. Clinical experience has shown that cannulized peripheral arteries may develop vasospasm, however, resulting in catheter failure. When this occurs, blood cannot be drawn or dripped from the peripheral arterial catheter, and the arterial waveform may be dampened or flat.

[Endovascular treatment of vasospasm following subarachnoid aneurysmal haemorrhage]

An endovascular treatment of vasospasm following a subarachnoid aneurysmal haemorrhage is to be implemented if the patient presents clinical or biological symptoms arguing for brain ischemia in conjunction with increased Doppler velocities despite well controlled systemic haemodynamic. Treatment might be either pharmacological or haemodynamic. Calcium and phosphodiesterase inhibitors can be administered. The former could also provide a neuroprotective effect as compared to the latter. In Europe, nimodipine is widely used whereas nicardipine and verapamil are the major molecules administered in North America where iv nimodipine is not FDA approved. Papaverine is less used nowadays because of its short duration of action and of the risk of aggravation of raised intracranial pressure. Balloon angioplasty has a long lasting effect but can be applied only to proximal spasm. Complications of its use are rare but life threatening. In some cases, both the pharmacological approach and the mechanical approach are used in combination.

[Vegetotropic therapy and hypobaric hypoxic adaptation in gallbladder motor dysmotility]

The study of 67 chronic biliary patients (36 - gallbladder dysfunction, 25 acalculuous cholecystitis, 6 - cholelithiasis) was revealed their functional dysadaptation characterized by gallbladder dysmotility and autonomic dysfunction. Vegetotropic therapy (Propranolol, Metoclopramid, Atropine) according to the autonomic regulation activity has advantages in correction of the gallbladder dysmotility in comparison to the routine pharmacotherapy. Hypobaric hypoxic adaptation results in the increase of gallbladder emptying that opens perspectives for the non-pharmacological correction of the gallbladder hypokinetic dyskinesia.

Phosphodiesterase 10A inhibitors: a novel approach to the treatment of the symptoms of schizophrenia

A disruption of corticostriatal signaling is believed to underlie the psychotic symptoms of schizophrenia and also contribute to many of the cognitive deficits associated with this disorder. Phosphodiesterase (PDE)10A is a dual substrate PDE highly expressed in striatal medium spiny neurons. Biochemical and behavioral studies indicate that the inhibition of PDE10A enhances striatal output by increasing activity in the cGMP and cAMP signaling pathways. PDE10A inhibitors reduce exploratory activity and antagonize the stimulant response to both amphetamine and N-methyl-d-aspartate antagonists such as phencyclidine. Consistent with their potential as antipsychotic agents, PDE10A inhibitors are potent antagonists of conditioned avoidance responding. The presence of PDE10A in both striatal output pathways may reduce the incidence and severity of dopamine D2 receptor antagonist-like side effects, including extrapyramidal symptoms. In addition, by enhancing corticostriatal signaling, PDE10A inhibitors have the potential to improve some of the cognitive symptoms of schizophrenia.

Treating Erectile Dysfunction in Renal Transplant Recipients

Erectile dysfunction is common in male kidney transplant recipients. Interference with the physiology of erections can be attributed to recipient co-morbidities, the renal transplant operation, medication adverse effects, relationship problems and changes in mental health. A treatment-oriented evaluation of erectile dysfunction allows the development of treatment plans that are patient-specific. Hypo-gonadal men whose hormone parameters do not improve after renal transplantation may respond to testosterone replacement therapy. Use of recommended doses of the phosphodiesterase-5 inhibitor sildenafil does not significantly modify trough concentrations of the calcineurin inhibitors ciclosporin and tacrolimus or result in impaired renal allograft function. Tacrolimus has been shown to increase the peak concentration and prolong the elimination half-life of sildenafil in kidney transplant recipients. Daily administration of sildenafil has resulted in decreased blood pressure in kidney transplant recipients with treated hypertension and tacrolimus immunosuppression. Intracavernosal injections of alprostadil, with or without papaverine and phentolamine, are effective treatments for erectile dysfunction after renal transplantation and have not resulted in alterations of ciclosporin concentrations or in deterioration of renal function. Penile prostheses can be successfully implanted after pelvic organ transplantation without significant risk of infection.

Different hemodynamic responses by color Doppler ultrasonography studies between sildenafil non-responders and responders

AIM

To determine if there are different penile hemodynamic patterns between sildenafil non-responders and responders by using color Doppler ultrasonography.

METHODS

A total of 69 erectile dysfunction (ED) patients aged 22-79 years were enrolled into the present study. Thirty-eight (55.1%) men with ED who did not respond to four attempts of treatment with 100 mg sildenafil after re-education were classified as sildenafil non-responders. A combination of three vasodilator drugs, 1.25 mg papaverine, 0.4 mg phentolamine and 5 mg prostaglandin E1, was given by intracavernous injection before penile Doppler ultrasonography was carried out. The erectile response to intracavernous injection and vascular parameters including peak systolic velocity (PSV), resistance index (RI), end diastolic velocity (EDV) and cavernosa artery diameter (CD) were measured and the results between sildenafil non-responders and responders were compared.

RESULTS

No statistical difference in vascular parameters measured by Doppler ultrasonography studies between non-responders and responders was noted. Sildenafil non-responders had a poorer penile rigidity response to intracavernous injection than responders (P < 0.05). Among patients with adequate PSV (>or=30 cm/s) and abnormal EDV (> 5 cm/s), individuals in the non-responder group had fewer positive responses to intracavernous vasodilator injection than in the responder group (35.3% vs. 72.2%, P < 0.05). Advanced age and comorbidity with diabetes mellitus were significantly associated with sildenafil non-response (P < 0.05).

CONCLUSION

Sildenafil non-responders were characterized by a poorer penile rigidity response to intracavernous injection and had an associated impaired veno-occlusive mechanism. Advanced age and comorbidity with diabetes mellitus were two common factors associated with non-response.

[Behaviour of near-infrared cerebral oximetry readings during percutaneous carotid angioplasty]

BACKGROUND

Transluminal percutaneous carotid angioplasty and stenting (CAS) carries a risk of cerebral ischemia, hemorrhage, or edema due to relative hyperemia and hemodynamic instability during and after the procedure. Noninvasive monitoring of near-infrared regional cerebral oxygen saturation (SrO2) offers an indirect way to estimate cerebral blood flow.

OBJECTIVE

To evaluate the behaviour of SrO2 during CAS and the usefulness of this variable for continuous monitoring of cerebral blood flow variation and neurological status.

MATERIAL AND METHODS

Prospective study of 25 patients scheduled for unilateral CAS under monitored anesthesia care. SrO, and other hemodynamic and clinical data were recorded. A change in SrO2 (deltaSrO2) of 15% or more in comparison with the baseline value and lasting more than 30 seconds was considered clinically significant. Neurological complications in the first 24 hours were also registered.

RESULTS

Baseline SrO, ranged from 51% to 75%. With administration of papaverine SrO2 values increased by a mean (SD) of 5.6% (6%) (P<.05 vs baseline). They decreased during angioplasty, -2.5% (5.7%) (P<.05 vs baseline), increased after 5 minutes, and fell again at 30 minutes to a level 3% (6.54%) above baseline. Two patients showed signs of elevated intracranial pressure after the procedures and also had ASrO2 readings exceeding 15%; measures to lower arterial hypertension reduced SrO2 in these patients.

CONCLUSION

High interindividual variability of absolute SrO2 values has been confirmed. SrO, fluctuates with maneuvers that change cerebral blood flow in the same way. Changes can precede the onset of other clinical signs.

[Functional state of kidneys and upper urogenital tract in patients with intraligamentary ovarian cysts in pre and postoperative periods during the treatment with spasmolytics]

25 patients with different types of intraligamentary ovarian cysts were observed. The main diagnostic method of the patients with intraligamentary cysts was ultrasound Dopplerometry of arteries iliaca interna, uterine and renalis using the following indicators: pulsatory index, resistance index, maximal blood speed. Determination of these indicators was conducted before operation, on 10 and 30 days after operation. In post-operation period we found that in the side free from the tumor's development, all doppleromethric indices were substantially normalised.

Update on endovascular therapies for cerebral vasospasm induced by aneurysmal subarachnoid hemorrhage

Cerebral vasospasm remains a major source of morbidity and death in patients with aneurysmal subarachnoid hemorrhage (SAH). When vasospasm becomes refractory to maximal medical management consisting of induced hypertension and hypervolemia and administration of calcium channel antagonists, endovascular therapies should be considered. The primary goal of endovascular treatment is to increase cerebral blood flow to prevent cerebral infarction. Two of the more frequently studied endovascular treatments are transluminal balloon angioplasty and intraarterial papaverine infusion. These two have been used either alone or in combination for the treatment of vasospasm. Other pharmacological vasodilating agents currently being investigated are intraarterial nimodipine, nicardipine, verapamil, and milrinone. Newer intraarterial agents, such as fasudil and colforsin daropate, have also been investigated. In this article the authors review the current options in terms of endovascular therapies for treatment of cerebral vasospasm. The mechanism of action, technique of administration, clinical effect and outcomes, and complications of each modality are discussed.

Endovascular treatment strategies for cerebral vasospasm

Cerebral vasospasm is a significant cause of morbidity and mortality in patients who have sustained a subarachnoid hemorrhage from aneurysm rupture. Symptomatic cerebral vasospasm is also a strong predictor of poor clinical outcome and has thus drawn a great deal of interest from cerebrovascular surgeons. Although medical management is the cornerstone of treatment for this condition, endovascular intervention may be warranted for those in whom this treatment fails and in whom symptomatic vasospasm subsequently develops. The rapid advancements in endovascular techniques and pharmacological agents used to combat this pathological state continue to offer promise in broadening the available treatment armamentarium. In this article the authors discuss the rationale and basis for using the various endovascular options for the treatment of cerebral vasospasm, and they also discuss the limitations, complications, and efficacy of these treatment strategies in regard to neurological condition and outcome.

Effect of intraarterial papaverine and/or angioplasty on the cerebral veins in patients with vasospasm after subarachnoid hemorrhage due to ruptured intracranial aneurysms

Object

The goal in this study was to determine if there was a change in intracranial venous diameters after endo-vascular treatment of carotid distribution vasospasm caused by subarachnoid hemorrhage.

Methods

The venous diameters were measured in all patients who received intraarterial papaverine and/or balloon angioplasty for treatment of vasospasm during the study period of 3 years. To evaluate the veins of Labbé and Trolard, the straight sinus, and the superior sagittal sinus (SSS), measurements were performed in a blinded manner with the aid of a magnification loupe. Predetermined sites were evaluated on angiograms obtained before and after endovascular treatment. Forty-three treatments in 26 patients were included: 18 patients (33 territories) were treated with intraarterial papaverine alone, four (four territories) were treated with balloon angioplasty alone, and four (six territories) were treated with both papaverine infusion and angioplasty.

The mean measured venous diameters increased significantly after addition of papaverine (10.9%), and also after combined papaverine and angioplasty (4.2%). There was no statistically significant increase in the mean venous diameters after angioplasty alone. If the initial intracranial pressure (ICP) was less than 15 mm Hg before treatment, the veins showed a greater tendency to dilate than if the initial ICP measurements were greater than 15 mm Hg. The straight sinus and the SSS increased more in diameter than the veins of Labbé and Trolard. There was no statistically significant correlation between the change in venous diameters with treatment and ICP.

Conclusions

Endovascular treatment produces measurable increases in intracranial venous diameters. However, these changes do not correlate with changes in ICP.

Intra-arterial papaverine used to treat cerebral vasospasm reduces brain oxygen

INTRODUCTION

Intra-arterial papaverine (IAP) is used to treat symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). IAP, however, can increase intracranial pressure (ICP). In this study we examined whether IAP alters brain oxygen (BtO2).

METHODS

Poor clinical grade (Hunt & Hess IV or V) SAH patients who underwent continuous ICP and BtO2 monitoring during IAP infusion for symptomatic cerebral vasospasm were evaluated as part of a prospective observational study.

RESULTS

Data are available for five patients (median age 58) who received IAP for cerebral vasospasm 4 to 7 days after SAH. In each patient, angiographic vasospasm was improved on postinfusion angiogram. Mean ICP before IAP was 23.04 +/- 1.18 mmHg; it increased immediately after IAP infusion and remained elevated (29.89 +/- 1.18 mmHg; p < 0.05) during IAP and for approximately 10 minutes after IAP ended. Baseline mean arterial pressure (MAP) was 110.55 +/- 1.36 mmHg. During IAP treatment MAP remained stable (110.90 +/- 2.00 mmHg; p = 0.31). Mean BtO2 before IAP was 32.99 +/- 1.45 mmHg. There was a significant BtO2 decrease in all patients during IAP to a mean of 22.96 +/- 2.9 mmHg (p < 0.05). BtO2 returned to baseline within 10 minutes after IAP ended. There was a modest relationship between the ICP increase and BtO2 decrease (R2 = 0.526).

CONCLUSION

IAP infusion to treat cerebral vasospasm following SAH can increase ICP and reduce BtO2. The IAP-induced reduction in BtO2 may help explain why IAP, although it reverses arterial narrowing, does not improve patient outcome.

Long-term treatment with intracavernosal injections in diabetic men with erectile dysfunction

AIM

To assess the behavior of patients with diabetes mellitus (DM) and erectile dysfunction (ED) during 10 consecutive years of treatment with self-injection of vasoactive drugs.

METHODS

Thirty-eight diabetic men, including 12 with type I and 26 with type II diabetes, were followed up regularly for 10 years after they began self-injecting for severe ED. Real time rigidity assessment was used for the objective determination of the initial dosage and then doses were regulated in order to introduce an erection suitable for penetration and maintenance of erection for approximately 30 min. Patients were followed up every two months, and doses were increased only when the treatment response was not satisfactory.

RESULTS

The number of injections used per year by the patients was reduced each year (mean numbers: 50 in the first year and 22.5 in the 10th) and treatment shifted towards stronger therapeutic modalities (mixtures of vasoactive drugs instead of prostaglandin E1 alone). Type I diabetic men were standardized to a level of treatment as early as 5 years after the initiation of treatment. That level was finally reached by type II patients after another 4-5 years.

CONCLUSION

Treatment with self-injections of vasoactive drugs in diabetic men with severe ED is a safe and effective alternative in the long term. Diabetic men of both types show the same preferences in quality and quantity of treatment after 10 years. The key point for maintenance in treatment is the adjustment of the therapeutic method and dosage to optimal levels for satisfactory erections.

Theories on the nature of the coupling between ventilation and gas exchange during exercise

For over a century of creative research, many theories on the possible mechanisms controlling respiration during exercise have been developed and discussed. One of the most enduring questions is certainly related to the mechanisms that can prevent P(a)(CO(2)) rising when CO(2) production increases. As multiple systems and structures are capable of increasing ventilation (V (E)), not all the mechanisms controlling respiration can provide a proper answer to this question. Indeed, exercise is a complex physiological condition combining motor activity with a change in metabolic rate. The most intriguing aspect of exercise is that when the changes in metabolism are dissociated from the motor and locomotor activity, the strategy 'chosen' by the respiratory control system is to follow the metabolic rate (or more precisely factors temporally associated with the pulmonary gas exchange rate) regardless of the motor act. The strategy used by the respiratory system during exercise therefore appears to select from among various sources of information the most relevant to follow the rate at which CO(2) is ultimately exchanged by the lungs. Yet, the nature of the signal(s) which prevents CO(2)/H(+) disturbance during exercise is the fundamental question addressed by this simple observation and remains to be clarified. This review illustrates the attempts of many physiologists to collect experimental evidence for theories which could provide satisfactory mechanisms accounting for the matching between ventilation and the rate at which CO(2) leaves the tissues and is exchanged at the lungs. More recent models based on somatic information of circulatory origin are presented and discussed.

Flow measurement before and after papaverine injection in above-knee prosthetic femoropopliteal bypass

OBJECTIVE

To investigate the value of intraoperative blood flow measurements on early and long-term patency of above-knee prosthetic femoropopliteal bypass.

METHODS

Flow was measured with a transit time flowmeter before (basal flow) and after an intragraft injection of papaverine (papaverine flow) in 87 operations (86 patients) between January 1990 and December 2001. Sixty-one grafts were of polyester, and 26 were of polytetrafluoroethylene. The operations were done under epidural anesthesia. The preoperative angiographic run-off score and clinical risk factors were recorded. Patency rates were analyzed with the product limit method and compared with the log-rank test. Variables found to be near significantly related to patency rates (P < .1) were included in a multivariate analysis performed with the Cox proportional hazard model.

RESULTS

Basal flow measurements were not related to patency. The 2- and 5-year patency rates for grafts with a papaverine flow < or = 500 mL/min were 48% and 18% compared with 66% and 52% for grafts with a papaverine flow > or = 500 mL/min. These differences were statistically significant (P = .012, hazard ratio, 2.6). Two- and 5-year patency rates for smokers vs nonsmokers were 44% and 18% vs 69% and 54%. The patency rates for patients with poor vs good run-off were 42% and 27% vs 66% and 31%. Smoking (P = .008, hazard ratio, 2.75) and poor run-off score (P = .009, hazard ratio, 2.38) were found to be independent risk factors for reduced patency rates. Poor run-off score did not correlate with low values of measured basal or papaverine flow.

CONCLUSIONS

Papaverine flow of < or = 500 mL/min is associated with reduced mid- and long-term patency rates. Additional antithrombotic medication and frequent follow-up for these grafts should be considered. The inferior patency rates of smokers and patients with poor run-off indicate that prosthetic bypass is less suitable for these groups of patients.

Interaction of papaverine with the enalapril-induced cough in guinea pig

BACKGROUND

Angiotensin Converting Enzyme Inhibitors (ACEIs) like enalapril are extremely effective in the treatment of hypertension and heart failure. One of the most important side-effects of these drugs which can lead to cessation of therapy is a persistant dry cough, induced because of increased bradykinin levels in the lung. Although antitussive alkaloids like codeine are effective in suppressing this cough, they too present a wide range of side-effects, most notably addiction.

OBJECTIVE

In a previous work we were able to show that noscapine, a non-narcotic antitussive agent, was able to decrease enalapril induced cough in guinea pigs. In this work, papaverine, another non-narcotic alkaloid found in opium latex was tested in the guinea pig model for antitussive activity.

METHOD

Cough was induced in enalapril pretreated guinea pigs by forcing the animals to inspire capsaicin aerosol in an air-tight chamber. Coughs were recorded in control animals and in those which had received different doses of papaverine. Characteristic changes in chamber air pressure, were detected by a pressure transducer.

RESULTS

. At low doses (0.5 and 0.25 mg/kg) papaverine was able to decrease enalapril induced cough. CONCLUSION. This effect was not mediated by the action of the drug on mu receptors and was only observed in animals treated with enalapril.