Pantoprazole provides rapid and sustained symptomatic relief in patients treated for erosive oesophagitis.

BACKGROUND: Effective symptom control is a primary concern of most heartburn suffers. AIM: To compare the safety and efficacy of pantoprazole, placebo and the H2 antagonist nizatidine in relieving symptoms in patients with erosive oesophagitis. METHODS: Data from two randomized, double-blind studies were pooled. Patients received pantoprazole 10, 20 or 40 mg, or placebo daily (study 1, n = 603), or pantoprazole 20 or 40 mg daily or 150-mg nizatidine b.d. (study 2, n = 243) for either 4 or 8 weeks. Endoscopy was performed at baseline, week 4 and week 8. Persistent absence of symptoms was defined as the first day that no symptoms were reported by the patient on that day or any subsequent study day. RESULTS: A significantly higher percentage (P < 0.05) of pantoprazole patients reported elimination of all symptoms by week 8. Daytime heartburn, night-time heartburn and regurgitation were significantly better controlled with pantoprazole (with a dose-response at most time-points). Absence of symptoms was a powerful predictor of healing; presence of symptoms correlated poorly. CONCLUSION: Pantoprazole is more effective than placebo or nizatidine for controlling heartburn and acid regurgitation in patients with erosive oesophagitis. Relief of GERD symptoms is highly predictive of healing of erosive oesophagitis at 4 and 8 weeks.

Prevention of erosive oesophagitis relapse with pantoprazole.

AIM: To compare the safety and efficacy of pantoprazole and ranitidine in maintaining erosive oesophagitis healing. METHODS: Gastro-oesophageal reflux disease patients (349) with endoscopically documented healed erosive oesophagitis (grade 0 or 1) were randomly assigned to receive pantoprazole (10, 20 or 40 mg/q.d.s.) or ranitidine (150 mg/b.d.). Erosive oesophagitis status was assessed endoscopically at months 1, 3, 6 and 12 or when relapse symptoms appeared (relapse = reappearance of erosive oesophagitis grade 2 within 12 months). Symptom-free days were also assessed. RESULTS: Pantoprazole 20- and 40-mg were significantly more effective than ranitidine in maintaining healing regardless of initial erosive oesophagitis grade. Response was dose-related. After 12 months 78, 55, 46 and 21% of patients remained healed (40-, 20-, 10-mg pantoprazole and ranitidine). Pantoprazole 40-mg produced significantly more symptom-free days (83%) than ranitidine (58%). Heartburn-free days/nights were significantly higher with pantoprazole 40-mg (92 and 93%) than ranitidine (73 and 77%). The most frequent reason for discontinuation, unsatisfactory efficacy, occurred most often with ranitidine (P < 0.001). CONCLUSION: Once-daily pantoprazole therapy prevented relapse of healed erosive oesophagitis more effectively than ranitidine and with fewer heartburn days. Response to pantoprazole was dose-related. Pantoprazole 40-mg was the most effective regimen and consistent in maintaining erosive oesophagitis healing with a good safety and tolerability profile.

Pantoprazole maintenance therapy prevents relapse of erosive oesophagitis.

OBJECTIVES: To compare the safety and efficacy of pantoprazole with ranitidine for the maintenance of endoscopically documented healed (grade 0 or 1) erosive oesophagitis. METHODS: Patients (371) were randomly assigned to receive pantoprazole 10, 20 or 40 mg or ranitidine 150 mg. Endoscopies were performed after 1, 3, 6 and 12 months or when symptoms suggesting relapse (grade = 2) developed. Gastric biopsies were obtained at baseline and on at least one postbaseline visit. Symptom-free days and Gelusil use were assessed. RESULTS: Pantoprazole was significantly (P < 0.001) more effective in maintaining erosive oesophagitis healing. After 12 months, 33%, 40%, 68% and 82% of patients remained healed for the ranitidine and pantoprazole 10, 20 and 40 mg groups, respectively. Daytime and night-time heartburn were eliminated in > 90% of days for the pantoprazole 40 mg group. Gelusil use was significantly lower with pantoprazole 20 and 40 mg than with ranitidine (P < 0.02) during the first 9 months. CONCLUSIONS: Twelve months of maintenance therapy with pantoprazole (10-40 mg once daily) was superior to ranitidine (150 mg twice daily) in maintaining erosive oesophagitis healing. Pantoprazole 40 mg provided the most consistent efficacy and was well tolerated.

Comparison of the efficacy of pantoprazole vs. nizatidine in the treatment of erosive oesophagitis: a randomized, active-controlled, double-blind study.

BACKGROUND: Pantoprazole is a proton pump inhibitor approved for the treatment of erosive oesophagitis and gastro-oesophageal reflux disease. AIM: To compare the efficacy and safety of pantoprazole vs. nizatidine for the treatment of symptomatic gastro-oesophageal reflux disease and endoscopically documented erosive oesophagitis (grade > or = 2). METHODS: A multicentre, double-blind, randomized, active-controlled study (221 patients) was performed to compare 20 and 40 mg pantoprazole daily with nizatidine 150 mg b.d. (maximum, 8 weeks). The primary end-point was endoscopic healing of erosive oesophagitis (grade 1 or 0). The secondary end-point was symptomatic improvement. RESULTS: Healing averaged 61%, 64% and 22% for pantoprazole 20 mg, pantoprazole 40 mg and nizatidine 150 mg, respectively, at 4 weeks, and 79%, 83% and 41% at 8 weeks (P < 0.05, differences between groups at both points). Starting on day 1 of symptom assessment, significantly fewer pantoprazole-treated patients reported night-time heartburn and regurgitation compared with nizatidine-treated patients. Symptoms of gastro-oesophageal reflux disease were completely eliminated in 68% and 65% of patients in the pantoprazole 20-mg and 40-mg groups and in 28% of patients in the nizatidine group at study completion. The difference between each pantoprazole group and the nizatidine group was significant (P < 0.05). CONCLUSIONS: Pantoprazole, at single daily doses of 20 mg and 40 mg for up to 8 weeks, provides more rapid relief of symptoms and superior healing of erosive oesophagitis than nizatidine 150 mg b.d., and is well tolerated.

Dose-dependent control of intragastric pH by pantoprazole, 10, 20 or 40 mg, in healthy volunteers.

BACKGROUND: Proton pump inhibitors have emerged as the most effective class of drugs for the treatment of gastro-oesophageal reflux. Pantoprazole is a proton pump inhibitor that has demonstrated high clinical efficacy. AIM: To evaluate the effect of once-daily doses of pantoprazole, 10, 20 and 40 mg, on gastric acidity in healthy volunteers. METHODS: Thirty-six subjects received pantoprazole in a three-way crossover design study. Ambulatory 24-h intragastric pH and distal oesophageal pH were monitored at baseline and on the last day of each treatment period. The measured endpoints were the median intragastric and oesophageal pH, the percentage of time the intragastric pH < 4 and oesophageal pH < 4 and the area under the curve for gastric acidity over 24 h. Safety was evaluated by incidence and severity of adverse events. RESULTS: Pantoprazole demonstrated a linear dose- dependent suppression of gastric acidity over the dose range 10-40 mg. The dose of 40 mg demonstrated a significantly greater response than the lower doses, particularly at night. All pantoprazole doses were well tolerated. CONCLUSIONS: Pantoprazole demonstrates a dose-related effect in the range 10-40 mg once daily. The once-daily dose of 40 mg provides the highest and most consistent control of gastric pH, especially at night.

[A case of partial hearing recovery after ablation of cerebello-pontine angle neurinoma]. / Un cas de récupération partielle de l'audition après l'ablation d'un neurinome de l'angle pontocérébelleux.

A case of a 44 year-old woman farmer with a total deafness and lack of vestibular function on the left side operated upon the cerebello-pontine cystic neuroma 2.5 x 2.0 x 1.5 cm large via the retromastoidal craniectomy is presented. Despite of the negative audiological tests' results the cochlear nerve flatten on the tumor was cautiously separated. Some time after surgery, she observed "a partial recovery of hearing" in the operated ear confirmed by the tonal (mean 0.5-2 kHz 36 dBHL) vocal SRT 70 dB), BERA and EOAEs tests. The paralysis of the left vestibular function did not recover. In consecutive audiogram a notch at 6 kHz 15 dB deep appeared in the operated ear and one can presume an increased vulnerability of this ear to the noise of the agricultural machines used by then by the patient.

Comparative efficacy of new investigational agents against Helicobacter pylori.

BACKGROUND: Emergence of antibiotic resistant Helicobacter pylori has necessitated the identification of alternate therapies for the treatment of this infection. AIM: To assess the in vitro efficacy of two investigational agents: DMG-MINO CL 344 (a N,N-dimethylglycylamido derivative of minocycline), and davercin, a cyclic carbonate of erythromycin A as compared to older antibiotics (clarithromcyin, azithromycin, minocycline, tetracycline, ofloxacin, ciprofloxacin, cefixime) against clinical isolates of H. pylori. METHODS: Testing was performed using the agar dilution method approved by the NCCLS subcommittee on antimicrobial susceptibility testing, Helicobacter pylori working group. Under these guidelines, Mueller-Hinton agar containing 5% aged sheep blood was used. All incubations were done under CampyPak Plus conditions for 72 h at 37 degrees C. The drug concentrations in the agar ranged from 0.016 to 16 microg/mL. Twenty-one clarithromycin-resistant and 16 clarithromycin-susceptible clinical isolates of H. pylori obtained from patients with duodenal ulcer were used. H. pylori ATCC 43504 was used as the control in all determinations. RESULTS: Against clarithromycin susceptible isolates, all antimicrobial agents except the fluoroquinolones were highly effective. Against clarithromycin-resistant H. pylori, the MIC50/MIC90 values showed that the tetracyclines and cefixime were the most efficacious agents. The fluoroquinolones and macrolides were ineffective. Macrolide cross-resistance was detected. CONCLUSION: Macrolide cross-resistance prevents the use of this entire class of antimicrobials when clarithromycin resistance is present. Tetracyclines and cefixime are possible alternative agents for the treatment of H. pylori infection in these patients.

Replacement of oral proton pump inhibitors with intravenous pantoprazole to effectively control gastric acid hypersecretion in patients with Zollinger-Ellison syndrome.

OBJECTIVES: In patients with Zollinger-Ellison syndrome (ZES) or other conditions requiring oral doses of proton pump inhibitors, it frequently becomes necessary to use parenterally administered gastric acid inhibitors. However, i.v. histamine-2 receptor antagonists are not effective at usual doses and lose their effectiveness because of tachyphlaxis. With the approval in the United States of i.v. pantoprazole, a substituted benzimidazole available in i.v. formulation, it will become possible to acutely manage gastric acid secretion in the acute care setting of a hospital. This study was developed to monitor the safety and establish the efficacy of i.v. pantoprazole as an alternative to oral proton pump inhibitors for the control of gastric acid hypersecretion in patients with ZES. METHODS: The efficacy of replacing oral PPI therapy with i.v. pantoprazole was evaluated in 14 ZES patients. After study enrollment, patients taking their current doses of oral PPI (omeprazole or lansoprazole) were switched to pantoprazole i.v. for 6 days during an 8-day inpatient period in the clinical research center. Effective control was defined as an acid output (AO) of < 10 mEq/h (< 5 mEq/h in patients with prior gastric acid-reducing surgery). RESULTS: The mean age of the 14 patients enrolled in the study was 52.4 yr (range = 38-67). Mean basal AO was 0.55 +/- 0.32 mEq/h and mean fasting gastrin was 1089 pg/ml (range = 36-3720). Four patients were also diagnosed with the multiple endocrine neoplasia type I syndrome, nine were male, and two had previously undergone acid-reducing surgery. Before study enrollment, gastric acid hypersecretion was controlled in nine of 14 patients with omeprazole (20-200 mg daily) and five of 14 with lansoprazole (30-210 mg daily). In the oral phase of the study all patients had adequate control of gastric acid secretion, with a mean AO of 0.55 +/- 0.32 mEq/h (mean +/- SEM). Thereafter, 80 mg of i.v. pantoprazole was administered b.i.d. for 7 days by a brief (15 min) infusion and the dose was titrated upward to a predetermined maximum of 240 mg/24 h to control AO. A dose of 80 mg b.i.d. of i.v. pantoprazole controlled AO in 13 of 14 of the patients (93%) for the duration of the study (p > 0.05 compared to baseline values for all timepoints). One sporadic ZES patient (oral control value = 0.65 mEq/h on 100 mg of omeprazole b.i.d. p.o.) was not controlled with 80 mg of i.v. pantoprazole b.i.d. and dosage was titrated upward to 120 mg b.i.d. after day 2. CONCLUSIONS: There were no serious adverse events observed. Intravenous pantoprazole provides gastric acid secretory control that is equivalent to the acid suppression observed with oral proton pump inhibitors. Most ZES patients (93%) maintained effective control of AO previously established with oral PPIs when switched to 80 mg of i.v. pantoprazole b.i.d.; however, for difficult-to-control patients, doses > 80 mg b.i.d. may be required.

Oral pantoprazole for erosive esophagitis: a placebo-controlled, randomized clinical trial. Pantoprazole US GERD Study Group.

OBJECTIVES: The aim of this dose-response study was to compare the effectiveness of 10 mg, 20 mg, and 40 mg of pantoprazole with that of placebo tablets in the healing and symptom relief of gastroesophageal reflux disease associated with erosive esophagitis, and to determine the optimal dose. METHODS: A total of 603 patients with endoscopically confirmed (Hetzel-Dent scale) erosive esophagitis of grade 2 (64.5%) or grades 3 or 4 (35.3%) were enrolled in a double-blind, multicenter study and randomly assigned to receive pantoprazole (10 mg, 20 mg, or 40 mg) or placebo, administered once daily in the morning, for 4 or 8 wk depending on healing. RESULTS: The healing rates after 4 wk for placebo and pantoprazole 10 mg, 20 mg, and 40 mg/day were 14%, 42%, 55%, and 72%, respectively (p < 0.001 for all doses of pantoprazole vs placebo). Cumulative healing rates after 8 wk for placebo and pantoprazole 10 mg, 20 mg, and 40 mg/day were 33%, 59%, 78%, and 88%, respectively (p < 0.001 for all doses of pantoprazole vs placebo). The 40-mg pantoprazole dose produced greater rates of healing and earlier healing of esophagitis than either the 10- or 20-mg dose, regardless of severity. Pantoprazole, at any dose, was significantly more effective than placebo in relieving reflux symptoms. Patients on pantoprazole 40 mg experienced relief of symptoms on day 1 of treatment. No serious treatment-related adverse events occurred. CONCLUSIONS: Pantoprazole was safe and effective for healing erosive esophagitis and provided rapid symptomatic relief. These results indicate that pantoprazole offers a new option for treatment of erosive esophagitis. Among the three doses studied, the 40-mg dose was the most effective.

Intravenous pantoprazole rapidly controls gastric acid hypersecretion in patients with Zollinger-Ellison syndrome.

BACKGROUND & AIMS: Parenteral control of gastric acid hypersecretion in conditions such as Zollinger-Ellison syndrome (ZES) or idiopathic gastric acid hypersecretion is necessary perioperatively or when oral medications cannot be taken for other reasons (e.g., during chemotherapy, acute upper gastrointestinal bleeding, or in intensive care unit settings). METHODS: We evaluated the efficacy and safety of 15-minute infusions of the proton pump inhibitor pantoprazole (80-120 mg every 8-12 hours) in controlling acid output for up to 7 days. Effective control was defined as acid output >10 milliequivalents per hour (mEq/h) (<5 mEq/h in patients with prior acid-reducing surgery) for 24 hours. RESULTS: The 21 patients enrolled had a mean age of 51.9 years (range, 29-75) and a mean disease duration of 8.1 years (range, <0.5-21); 13 were male, 7 had multiple endocrine neoplasia syndrome type I, 4 had undergone acid-reducing surgery, 2 had received chemotherapy, and 13 had undergone gastrinoma resections without cure. Basal acid output (mean +/- SD) was 40.2 +/- 27.9 mEq/h (range, 11.2-117.9). In all patients, acid output was controlled within the first hour (mean onset of effective control, 41 minutes) after an initial 80-mg intravenous pantoprazole dose. Pantoprazole, 80 mg every 12 hours, was effective in 17 of 21 patients (81%) for up to 7 days. Four patients required upward dose titration, 2 required 120 mg pantoprazole every 12 hours, and 2 required 80 mg every 8 hours. At study end, acid output remained controlled for 6 hours beyond the next expected dose in 71% of patients (n = 15); mean acid output increased to 4.0 mEq/h (range, 0-9.7). No serious or unexpected adverse events were observed. CONCLUSIONS: Intravenous pantoprazole, 160-240 mg/day administered in divided doses by 15-minute infusion, rapidly and effectively controlled acid output within 1 hour and maintained control for up to 7 days in all ZES patients.

Secretin, cholecystokinin and the biliary canalicular secretion in the rat.

An attempt has been made to further assess which fraction of bile can be stimulated by the main gastrointestinal hormones in rats. In the cannulated conscious animals the i.v. infusions of glucagon, impure Boots secretin, impure Boots cholecystokinin (CCK) and OP-CCK resulted in 8.9% (N.S.), 68.5% (P < 0.001), 88.7% (P < 0.001) and 19.0% (P < 0.05) increase in the estimated bile acid-dependent bile flow (BAF) and in 25.4% (P < 0.01), 49.2% (P < 0.001), 44.5% (P < 0.001) and 1.6% (N.S.) increase in the estimated bile acid-independent bile flow (BAIF), respectively as compared to the control values. When the calculated BAF values corresponding to the bile acid impurities in Boots secretin and Boots CCK were subtracted from BAF and BAIF values obtained during hormone infusions (the corrected values), the increase in both BAF and BAIF was equal to 38.9% (P < 0.02) and 29.4% (P < 0.02) during Boots secretin infusion and to 61.1% (P < 0.01) and 29.4% (P < 0.02) during Boots CCK infusion, respectively as compared to the control values. It can be suggested that the hormonal impurities in the Boots preparations interacting with the principal hormonal component are able to stimulate BAF in the rat. Further extensive study embracing the interactions of the purified gut hormones may confirm their role in the control of canalicular bile secretion in the rat.

Effect of hyperglycemia and the aldose reductase inhibitor tolrestat on sural nerve biochemistry and morphometry in advanced diabetic peripheral polyneuropathy. The Tolrestat Study Group.

Tolrestat is a well tolerated nonhydantoin aldose reductase inhibitor that has been reported to improve nerve conduction in diabetic animals and humans. Its effects on nerve biochemistry and structure have not been studied in patients with diabetic neuropathy. Patients with advanced diabetic neuropathy treated with long-term open-label tolrestat were randomly assigned to continuation on drug treatment or to placebo-controlled drug withdrawal for 12 months. At the end of this period, sural nerve biopsies were obtained for measurement of glucose, sorbitol, and fructose content, and for detailed morphometric analysis. Tolrestat ameliorated the glucose-mediated increase in sorbitol and fructose in sural nerve tissue. No statistically significant differences in nerve morphometry emerged between the two groups; however, both treatment groups exhibited increased nerve-fiber regeneration and normalization of axo-glial dysfunction and segmental demyelination following long-term tolrestat treatment. These findings are similar to those previously reported in a placebo-controlled sequential nerve biopsy study with the aldose reductase inhibitor sorbinil. Thus tolrestat is a biochemically effective aldose reductase inhibitor in human diabetic nerve with potential therapeutic efficacy for diabetic neuropathy.

Withdrawal of the aldose reductase inhibitor tolrestat in patients with diabetic neuropathy: effect on nerve function. The Tolrestat Study Group.

A double-blind, placebo-controlled clinical trial was conducted to study the effects of discontinuing tolrestat, an aldose reductase inhibitor, on peripheral sensorimotor diabetic neuropathy. After an average of 4.2 years of continuous tolrestat use, 372 patients were randomly assigned to either placebo or continued tolrestat therapy and were followed for 52 weeks. After 3 months, patients who perceived worsening of symptoms of neuropathy were allowed to switch once to the alternate treatment group while maintaining the double-blind. Patients assigned to placebo had significant deterioration in motor nerve conduction velocity (MNCV) while those maintained on tolrestat did not (p < 0.05). The 28 patients who were randomly assigned to tolrestat and elected to switch to placebo had a significant deterioration in MNCV while the 36 assigned to placebo who switched to tolrestat had a significant improvement (p < 0.05). Treatment differences in favor of tolrestat were observed for sensation in the toes as well as for pain (p < 0.05). These data indicate that withdrawal from long-term treatment with tolrestat has a detrimental effect on several measures of diabetic neuropathy, whereas continuation of treatment is associated with stabilization of these measures, suggesting a continued role for polyol pathway activity in late neuropathy.

Carbohydrate content of apolipoprotein B-48 from rat chylomicrons of varying density.

Monosaccharide composition was determined in apolipoprotein B-48 (apoB) of chylomicrons of rat mesenteric lymph. Chylomicrons were separated into three fractions based on density. Triglyceride and apolipoprotein content were determined in each. ApoB was isolated and quantified using precipitation with isopropanol. Chylomicrons were collected in lymph under normal conditions, and with Poloxalene 2930 when chylomicron secretion was inhibited. Most of the triglyceride was carried in the least dense fraction, while the highest apoB content was in the most dense fraction under normal conditions. Mannose and galactosamine contents of apoB were similar in all fractions while contents of both glucosamine and galactose were highest in the least dense fraction. When chylomicron secretion was inhibited by Poloxalene, the amount of triglyceride recovered in the least dense fraction was significantly reduced. Despite the inhibition of lipid transport in the least dense fraction of chylomicrons by Poloxalene, there was little change in apoB recoveries and in the relative content of various monosaccharides in the apoB from each of the three fractions as compared to results obtained during lipid absorption under normal conditions. In conclusion, carbohydrate composition of apoB of chylomicrons is heterogeneous and varies with chylomicron density.

Non-invasive electrical stimulation of the ear canal as a communication aid in acquired total deafness.

Some profoundly deafened patients, who cannot be helped by sound amplification, claim to perceive auditory sensations when alternating currents up to 100 Hz are passed through electrodes applied to the skin of the external ear canal. A portable speech processor has been developed which supplies this current. The signal is a balanced square wave, the frequency of which is proportional to the first formant frequency. The amplitude is proportional to the intensity of voiced sounds. In order to fit the narrow frequency and dynamic range of the electrical stimulus, the speech processor produces a downward frequency transposition and strong limitation of the dynamic range. The device has been tested for (1) discrimination of environmental sounds; (2) question/statement discrimination; (3) identification of vowels and consonants in vowel/consonant/vowel context; (4) lip-reading with and without the prosthesis.

Hydrophobic surfactant inhibits hypercholesterolemia in pair-fed rabbits on a cholesterol-free, low-fat diet.

Poloxalene, a hydrophobic surfactant, is known to prevent hypercholesterolemia in animals fed a high-fat, high-cholesterol diet. It has not been demonstrated, however, whether this agent is of benefit when hypercholesterolemia is induced in animals by means other than the feeding of a high-fat diet. In this study, hypercholesterolemia was produced in rabbits by feeding a low-fat, cholesterol-free diet with dietary protein supplied by casein for a period of 8 weeks. Controls were given this diet without poloxalene and experimentals were given the diet with poloxalene. Total serum cholesterol levels increased in both groups, but the rise was greater for the control group. Lipoprotein analysis performed at the conclusion of the study showed significantly greater low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol levels in the control group as compared to the experimental group. Total protein and apolipoprotein B (apo B) were also greater in control LDL. It was concluded that poloxalene favorably affects this model of hypercholesterolemia as total serum cholesterol, LDL cholesterol, and LDL apo B were all less and the HDL cholesterol to LDL cholesterol ratio was higher in surfactant-treated rabbits.

Alterations of secretory pattern of intestinal lipoproteins by the benzoyl ester derivative of poloxalene surfactant (BEP).

Hydrophobic surfactant BEP was administered intraduodenally as part of lipid emulsion to rats with cannulated mesenteric lymphatic duct. The effect on the size and composition of intestinal triglyceride-rich lipoproteins (TRLp) was assessed by comparing the results with those obtained during infusion of the lipid emulsion alone. Administration of BEP decreased intestinal capacity to transport triglyceride and cholesterol in large TRLp, SF greater than 2000, and resulted in a significant reduction of total triglyceride in lymph. Non-apoB apolipoproteins decreased significantly in large and increased in small TRLp without appreciable change in total content. Contrary to these findings total apoB protein content increased significantly, primarily due to an increase in small TRLp. Changes in lipid and protein content of apolipoproteins produced by BEP resulted in increased ratios of apolipoproteins to lipids in TRLp. It was therefore concluded that inhibition of lipid transport by BEP was not a result of apolipoprotein deficiency. Discontinuation of BEP administration resulted in a prompt recovery of the intestinal lipid transport system.

Hydrophobic surfactant effects on aortic cholesterol accumulation and atherosclerosis in hypercholesterolemic rabbits.

Studies were performed in hypercholesterolemic rabbits to determine whether the hydrophobic surfactant, Poloxalene 2930 (Pol), is of benefit under these conditions. Lipoprotein analyses plus chemical and morphologic studies of the aorta were performed to evaluate the results. In one study, rabbits were made hypercholesterolemic by dietary means and then divided into two groups and given a cholesterol-free diet with one group additionally given Pol with treatment continued for 10 weeks. Pol treatment resulted in less atherosclerosis but the mechanism for this effect was not apparent from lipoprotein analysis. In the other study 3 groups of rabbits were given a cholesterol-rich diet for 16 weeks. Two groups received Pol supplement with one of these groups receiving a dose that was too small to prevent hypercholesterolemia. In this group plus the group on diet alone comparable degrees of hypercholesterolemia were maintained throughout the study. Lipoprotein abnormalities were similar in these two groups except that those on Pol had a more normal cholesterol to apolipoprotein B ratio. The amount of atherosclerosis in both groups was mild but aortic cholesterol content was much less for the Pol group. It is concluded that Pol limits cholesterol accumulation in the aortic wall of hypercholesterolemic rabbits and can retard the development of atherosclerosis.

Poloxalene 2930, a hydrophobic surfactant that prevents atherosclerosis, alters composition of rabbit lipoproteins.

Poloxalene 2930, a hydrophobic surfactant, was incorporated into an atherogenic diet at dose levels, 0.5% and 1% of the diet, and fed to rabbits for 10 weeks. Another group received plain atherogenic diet alone and a control group was fed chow. After this period, serum lipoproteins were separated by centrifugation and analyzed. The composition of lipoproteins from rabbits on atherogenic diet was abnormal. The cholesterol: triglyceride ratio of every lipoprotein fraction was significantly increased as was the cholesterol: protein ratio of very low density lipoproteins. Supplementing the diet with Poloxalene 2930 prevented these alterations. In all groups on the atherogenic diet the percentage of apolipoprotein E in VLDL and HDL increased. In the case of Poloxalene-treated rabbits this developed even though serum cholesterol levels were normal or slightly increased. It is concluded that Poloxalene 2930 has a systemic effect on lipoproteins which may contribute to its antiatherogenic action.