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PubMedDate not supplied

Radionuclide monitoring of left ventricular function after sublingual nifedipine administration at rest and during moderate physical activity.

BACKGROUND: This study investigates the acute effects of nifedipine administration on left ventricular (LV) function in patients with different degrees of heart failure at a fixed heart rate under resting conditions and during moderate physical activity. METHODS AND RESULTS: Eleven patients with non-rate-responsive DDD pacemakers were studied. According to baseline LV ejection fraction, patients were divided into 2 groups: 6 patients with an ejection fraction of less than 50% (group 1) and 5 patients with an ejection fraction of 50% or more (group 2). LV function was monitored by a radionuclide system (Vest) at rest and during moderate physical activity (10-minute walk test) before and after sublingual nifedipine administration (10 mg). In all patients, both the systolic blood pressure and diastolic blood pressure were significantly reduced (P <.05) 6 minutes after nifedipine administration. In group 1, end-diastolic volume and ejection fraction decreased after 3 minutes and remained significantly lower (P <.05) than resting values until 10 minutes after drug administration, whereas end-systolic volume was unchanged. In group 2, nifedipine induced a minor decrease in end-diastolic volume and a slight but not significant decrease in ejection fraction and end-systolic volume. During the walk test, nifedipine induced similar changes in all parameters of cardiac performance in both groups. CONCLUSIONS: In patients with impaired LV function, acute nifedipine administration has a negative effect on cardiac performance, which occurs before blood pressure reduction. On the other hand, during moderate physical activity, nifedipine does not affect the improvement in LV function.

Administration, Sublingual↗

PubMed2002

The clinical efficacy of piroxicam fast-dissolving dosage form for postoperative pain control after simple lumbar spine surgery: a double-blinded randomized study.

STUDY DESIGN: A prospective, randomized, double-blinded clinical trial was conducted. OBJECTIVE: To study the efficacy of piroxicam fast-dissolving dosage form in reducing postoperative pain after simple lumbar spine surgery. SUMMARY OF BACKGROUND DATA: Many reports mention the use of nonsteroidal antiinflammatory drug for relieving postoperative pain, but study still is lacking on their use in spine surgery. METHODS: For this study, 50 patients who underwent discectomy or one-level laminectomy were randomly sampled into two groups: 21 patients in the placebo control group and 29 patients in the study group. In addition to a normal postoperative analgesic regimen, each patient received placebo or piroxicam fast-dissolving dosage form (2 tablets administered sublingually 1 to 3 hours before surgery). This regimen was repeated with 2 tablets after 24 hours, then 1 tablet after 48 hours. Postoperative pain was evaluated every 6 hours by a visual analog scale for 3 days. The amount of morphine usage was measured on postoperative days 1, 2, and 3. Postoperative variables such as blood loss, length of wound, and time of operation also were recorded. RESULTS: There was no difference between the groups with respect to age, weight, height, gender, and type of operation. The postoperative pain of the study group, as measured by visual analog scale, showed significant improvement (P < 0.05) during the postoperative period 12 to 42 hours after surgery. The study group used less morphine, but their usage showed no significant difference on postoperative days 1, 2, and 3. When the visual analog scale between the types of operation was compared, the scale for the discectomy group was better than that for the laminectomy group. The results of the postoperative variables showed no difference between the groups in terms of postoperative blood loss, length of wound, and time of operation. CONCLUSIONS: Sublingual administration of piroxicam fast-dissolving dosage form after simple spine surgery is effective and efficient in relief of postoperative pain. Because of its low side effects and high toleration, piroxicam fast-dissolving dosage form may be considered as an alternative for postoperative pain control during the early postoperative period.

Administration, Sublingual↗

PubMed1995

Active and passive reaction of large arterial vessels to sublingual test with nitroglycerin.

The noninvasive method of oscillovasometry, devised previously, was applied to the estimation of arterial pressure, effective radius of large arterial vessels, a number of indices showing elastic vessel properties and change in tone of the vessels on the right upper limb just before sublingual administration of nitroglycerin (0.5 mg) to the patients and 4-5 min after it. A group of 96 patients with different levels of arterial pressure were examined. It was found that all the patients showed a pressure decrease and tachycardia, but about a half of them had a passive response in large arterial vessels in the form of a decrease in the vessel volume, while others showed a decrease in arterial vessel tone (vasodilation), i.e. an active vascular response. From the data we drew the conclusion that there are two types of vascular response (active and passive) and they do not depend on the initial level of arterial pressure. Nitroglycerin probably acts more effectively on large arteries with a high initial tone. The possible mechanism of this phenomenon is discussed.

Administration, Sublingual↗

PubMed1993

Effect of nifedipine on physiologic shunting and oxygenation in chronic obstructive pulmonary disease.

PURPOSE: To assess changes in physiologic shunting and oxygenation following short-term treatment with nifedipine in patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease. PATIENTS AND METHODS: Changes in pulmonary vascular pressure, pulmonary vascular resistance, venous admixture, and systemic arterial oxygen tension following sublingual administration of 20 mg of nifedipine were studied in 18 patients (13 men, 5 women; mean age of 59.7 [SD 7.2] years) using Swan-Ganz catheterization. These patients had a mean peak expiratory flow rate of 112 (SD 27) L/min (mean 22.2 [SD 12.2]% of predicted value), mean forced expiratory volume in 1 second (FEV1) of 0.84 (SD 0.23) L (mean 31.2 [SD 8.5]% of predicted value), mean FEV1/forced vital capacity ratio of 31.6 (SD 4.5), and mean carbon monoxide diffusing capacity of 6.8 (SD 1.96) mmol/min/kPa. RESULTS: There was a significant decrease in mean pulmonary vascular resistance (562 to 371 dyne sec.cm-5) and a significant reduction in the mean pulmonary arterial pressure (mean 32.8 to 23.6 mm Hg). Pulmonary venous admixture, however, increased significantly from the baseline mean of 44.6% (SD 16.1) to a mean of 56% (SD 15.6), and the mean arterial oxygen tension decreased from 5.8 (SD 1.3) kPa to 4.5 (SD 0.8) kPa at 60 minutes following drug administration (p < 0.001). CONCLUSION: The role of nifedipine in the treatment of pulmonary hypertension secondary to chronic bronchitis may be limited because of its deleterious effect on venous admixture.

Administration, Sublingual↗

PubMed2005

Vascular function in patients with lower extremity peripheral arterial disease: a comparison of functions in upper and lower extremities.

Peripheral arterial disease (PAD) is caused by atherosclerosis. Assessment of endothelial function in patients with PAD has been limited to that in forearm circulation in previous studies. The purpose of this study was to evaluate vascular function in upper and lower extremities in patients with PAD and to determine the relationship between the ankle-brachial pressure index (ABPI) and endothelial function in forearm and leg circulation. Forearm blood flow (FBF) and leg blood flow (LBF) responses to reactive hyperemia and sublingual administration of nitroglycerin (NTG) were measured using strain-gauge plethysmography in 57 PAD patients and 24 control patients. LBF during reactive hyperemia was significantly less in PAD patients than in control patients (p<0.001). FBF during reactive hyperemia in PAD patients was similar to that in control patients. NTG-induced vasodilation in upper and lower extremities was similar in the two groups. There was a significant relationship between the maximal LBF response to reactive hyperemia and the ABPI in both the patients with PAD and control patients (r=0.384, p<0.001), whereas maximal FBF response to reactive hyperemia was not correlated with ABPI (r=0.182, p=0.12). These findings suggest that LBF response to reactive hyperemia is impaired in PAD patients compared with that in control patients. Impairment of vascular reactivity of leg circulation may occur before impairment of vascular reactivity of forearm circulation in PAD patients and may be a better indicator of the degree of PAD than impairment of vascular reactivity of forearm circulation.

Administration, Sublingual↗

PubMed1997

Nitroglycerin tolerance at the platelet level in patients with angina pectoris.

Suppression of platelet aggregation may be an important component of the therapeutic effect of nitroglycerin (NTG). Because of the phenomenon of hemodynamic tolerance to NTG, we tested the hypothesis that the anti-platelet effects of NTG in humans are also subject to tolerance induction. In patients with stable angina who had not received nitrates for at least 24 hours before study, sublingual administration of NTG (300 microg; n = 17) attenuated the reversal of adenosine diphosphate-induced platelet aggregation by NTG applied in vitro. Three minutes after in vivo NTG administration, concentration of NTG producing 50% reversal of aggregation (C50) increased from 7.9 +/- 1.9 x 10(-5) to 5.5 +/- 0.3 x 10(-4) M (p <0.01); this change persisted for at least 60 minutes. There was no concomitant change in C50 values for sodium nitroprusside applied in vitro. Basal activity of platelet guanylate cyclase and its response to sodium nitroprusside were not affected after administration of NTG. Brief intravenous infusion of NTG (10 microg/min for 10 minutes) produced no significant changes in platelet responses to NTG in vitro. However, prolonged infusion of NTG (5 microg/min for 24 hours, patients with unstable angina pectoris, n = 11) caused suppression of in vitro platelet response to NTG. Platelets from patients receiving prophylactic nitrates (n = 19) were less responsive to the antiaggregatory effects of NTG in vitro than those from patients who had not received nitrates in the previous 24 hours (n = 21). Thus, clinical exposure to NTG, even in very low doses, induces tolerance to antiaggregatory effects of NTG. This phenomenon is not associated either with cross tolerance to sodium nitroprusside or with down-regulation of platelet guanylate cyclase.

Administration, Sublingual↗

PubMed2004

[Medical termination of pregnancy at 9-14 weeks gestation. Prospective study of 105 cases in Saint-Laurent-du-Maroni (French Guyana)].

OBJECTIVES: To demonstrate the effectiveness and safety of mifepristone 600mg with misoprostol 800 mg, for termination of pregnancy at 9-14 weeks gestation. PATIENTS AND METHODS: This prospective study included 105 women at 9 to 14 weeks gestation given 800 mg of vaginal misoprostol, 2 or 3 days after a single dose of 600 mg of mifepristone for pregnancy termination. Outcomes measures included mean expulsion time, the interval between fotal and placental expulsion, adverse effects, vaginal bleeding, requirement for analgesia, and hospital stay, analyzed by parity and gestational age. RESULTS: Pregnancy termination was successful in 92.4% of the patients without requirement for surgery. The mean time to expulsion was 6 hours. The fetus and placenta were expelled together in 79% of the cases. In 15% the conception products were retained in the cervical canal, and removed with a ring forceps. Additional misoprostol doses were necessary in 33% and analgesia (nalbuphine sublingually, mean dose was 10mg) in 56%. Significant bleeding was observed in 7.5%, leading to curettage in 2 patients. No statistically significant differences were found between the rate of success and term (9-12 versus 12-14) or parity. CONCLUSION: Combining oral mifepristone and vaginal misoprostol is a successful alternative to surgical termination of pregnancy, even after 9 weeks' gestation. The use of nalbuphine for analgesia improves acceptability; sublingual administration helps avoid invasive procedures. Before 14 weeks gestation, the legal limit for termination of pregnancy in France, the choice between the surgical and medical alternatives should be left to the patient.

Abortifacient Agents, Nonsteroidal↗

PubMed1999

Plasma concentrations of buprenorphine 24 to 72 hours after dosing.

BACKGROUND: This study evaluated plasma buprenorphine concentrations 24-72 h following sublingual administration of a dose of buprenorphine solution, ranging from 16 mg/70 kg to 44 mg/70 kg, administered on a daily or thrice-weekly schedule. Additionally, this study evaluated the effects of different thrice-weekly buprenorphine dose schedules on opiate use and withdrawal symptoms. METHODS: Opiate dependent subjects (n = 10) were maintained in an outpatient clinic for two 3-week periods at each of three thrice-weekly buprenorphine dose schedules (providing a weekly total buprenorphine dose of 64, 84 and 112 mg) and for 1 week of a daily buprenorphine dose of 16 mg/70 kg. Plasma samples were obtained 24, 48 and 72 h following administration of buprenorphine. Urine samples were also collected and opiate withdrawal symptoms, agonist effects and the use of heroin, cocaine, alcohol and other drugs, were assessed. RESULTS: Plasma levels showed a wide range of intra- and inter-subject variability. Nonetheless, higher doses of buprenorphine resulted in higher plasma concentrations at each time point and plasma concentration decreased with time. There were no significant differences in heroin use across dosing. Rates of withdrawal symptoms were low and did not differ across dosing schedules. CONCLUSIONS: In the two highest dose schedules, plasma levels 72 h following the administration of the highest dose and at 48 h after the lower dose, were comparable to plasma concentrations at 24 h following daily administration of 16 mg/70 kg of buprenorphine.

Administration, Sublingual↗

PubMed1998

Randomized, double-blind, placebo-controlled study of the preventive effect of supplemental oral vitamin C on attenuation of development of nitrate tolerance.

OBJECTIVES: This study sought to evaluate the preventive effect of vitamin C, an antioxidant, on the development of nitrate tolerance. BACKGROUND: Decreased intracellular production of cyclic guanosine monophosphate (cGMP) is a mechanism of nitrate tolerance, and increased superoxide levels and reduced activation of guanylate cyclase have been observed in vitro. METHODS: In this double-blind, placebo-controlled study, 24 normal volunteers and 24 patients with ischemic heart disease (IHD) were randomized to receive either vitamin C (2 g three times daily [vitamin C group, n=12]) or placebo (placebo group, n=12). The vasodilator response to nitroglycerin was assessed with forearm plethysmography by measuring the change in FBF before and 5 min after sublingual administration of 0.3 mg of nitroglycerin. Blood samples were simultaneously obtained to measure platelet cGMP levels. FBF was measured, and blood sampling was performed serially at baseline (day 0), 3 days after administration of vitamin C or placebo (day 3) and 3 days after application of a 10-mg/24-h nitroglycerin tape concomitantly with oral vitamin C or placebo (day 6). RESULTS: There were no differences between the vitamin C and placebo groups in percent increases in FBF (%FBF) or platelet cGMP levels (%cGMP) after administration of sublingual nitroglycerin on day O (%FBF: normal volunteers 31+/-8 vs. 32+/-10; patients with IHD 32+/-9 vs. 32+/-8; %cGMP: normal volunteers 37+/-9 vs. 39+/-10; patients with IHD 38+/-10 vs. 39+/-10 [vitamin C group vs. placebo group]) or day 3 (%FBF: normal volunteers 32+/-9 vs. 33+/-9; patients with IHD 31+/-10 vs. 31+/-10; %cGMP: normal volunteers 36+/-8 vs. 37+/-9; patients with IHD 39+/-11 vs. 38+/-10 [vitamin C group vs. placebo group]). The %FBF and %cGMP in the placebo group were significantly lower on day 6 than in the vitamin C group (%FBF: normal volunteers 30+/-8 vs. 19 4, p < 0.01; patients with IHD 29+/-9 vs. 17+/-6, p < 0.01; %cGMP: normal volunteers 36 10 vs. 17+/-6, p < 0.01; patients with IHD 37+/-11 vs. 15+/-5, p < 0.01 [vitamin C group vs. placebo group]). CONCLUSIONS: These results indicate that combination therapy with vitamin C is potentially useful for preventing the development of nitrate tolerance.

Adult↗

PubMed1999

Effect of preload alternations on a new Doppler echocardiographic index of combined systolic and diastolic performance.

The objective of the study was to assess the effect of preload alternations on a nongeometric Doppler index of combined systolic and diastolic myocardial performance (MPI). Doppler echocardiography was performed during Valsalva maneuver, passive leg lifting, and after sublingual administration of nitroglycerin in 50 healthy volunteers (group 1) and 25 patients (group 2) with previous myocardial infarction. MPI was significantly lower in group 1 (0.34 +/- 0.04) compared with group 2 (0.52 +/- 0.14), P <.0005. In group 1 MPI was significantly increased during preload manipulations (P =. 001). The largest change in MPI was induced by nitroglycerin (0.034 +/- 0.05). In group 2 no significant changes in MPI were found. In both groups peak E-wave velocity (P <.0005), E/A-ratio (P <.0005), and E-wave deceleration time (P <.0005) were found to change during preload alternations. In conclusion, we found in normal subjects and to a lesser extent in patients with previous myocardial infarction that MPI is influenced by preload.

Administration, Sublingual↗

PubMedDate not supplied

Improved detection of myocardial perfusion reversibility by rest-nitroglycerin Tc-99m-MIBI: comparison with TI-201 reinjection.

BACKGROUND: The role of nitroglycerin (NTG) in Tc-99m-methoxyisobutil isonitrile (MIBI) studies to improve the assessment of myocardial viability in patients with coronary artery disease and its comparison with TI-201 reinjection has not yet been clarified. This study aimed to test whether sublingual administration of NTG could improve the capability of Tc-99m-MIBI to detect reversibility in exercise-induced perfusion defects and to compare it with the TI-201 stress-redistribution-reinjection protocol. METHODS AND RESULTS: Thirty-eight patients (33 men, 5 women; mean age 49.3 +/- 8.2 years with previous myocardial infarction [mean evolution 7.1 +/- 3.9 months]) underwent exercise, redistribution, and reinjection TI-201 imaging, as well as exercise, rest, and NTG MIBI myocardial scintigraphy (3-day protocol). A total of 494 myocardial segments were assessed by quantitative analysis. Of the 136 myocardial segments with fixed defects on exercise-rest sestamibi imaging, 109 (80%) did not change after NTG MIBI study, and 27 (20%) demonstrated enhanced uptake. In the 140 myocardial segments with fixed defects on exercise-redistribution thallium imaging, 112 (80%) did not improve after TI-201 reinjection study, and 28 (20%) showed increased activity. The observed agreement on reversibility detection between NTG MIBI and TI-201 reinjection, with the 210 segments with perfusion defects used for this analysis on both studies, was 78%, with a significant kappa = .56 +/- .07 SE. CONCLUSION: Our data suggest that the use of an NTG MIBI protocol results in an incremental improvement for detecting exercise-induced perfusion defect reversibility and achieves results similar to those from a TI-201 reinjection protocol.

Administration, Sublingual↗

PubMed2001

Low-dose, sublingual AZT-monophosphate therapy for HIV+ patients?

AZT concentrations as low as 0.001 mg/l inhibit viral replication, while concentrations above 0.3 mg/l cause considerable damage to erythroid, myeloid progenitor cells and inhibit blastogenesis in mononuclear cells. Furthermore, AZT must be converted first to monophosphate and then to diphosphate and finally to triphosphate by the same enzyme: thymidine kinase (TK). Therefore, large doses of AZT overwhelm TK, causing massive production of monophosphate and reducing the production of di and triphosphate. Yet the recommended dosage of 100 mg AZT every 4 hours results in a peak concentration of 0.5 mg/l and a trough concentration of 0.1 mg/l (harmful to human cells and resulting in reduced production of triphosphate). On the other hand, sublingual administration of 1 mg AZT monophosphate every 8 hours (since the intracellular half life of AZT triphosphate is 3 hours) would be desirable, resulting in more damage to the virus and less harm to the patient. Finally, the small dose of monophosphate ensures that most of the AZT be converted to triphosphate, greatly increasing the efficiency and reducing the likelihood of the virus developing resistance due to reverse transcriptase binding to the similar but non inhibiting mono and diphosphate.

Administration, Sublingual↗

PubMed1989

Blood volume and right heart haemodynamics in abrupt hypotension following sublingual isosorbide dinitrate in acute myocardial infarction.

Arterial blood pressure and heart rate were measured in 43 patients with acute myocardial infarction and a systolic blood pressure greater than or equal to 120 mmHg during sublingual administration of 5 mg of isosorbide dinitrate. In 25 of them right heart haemodynamics were also measured. Severe (greater than or equal to 25%) hypotension developed in 12 patients (Group 1, systolic blood pressure 158 +/- 28 to 78 +/- 17 mmHg, mean +/- SD) but not in the remaining 31 (Group 2) and was accompanied by a fall in heart rate (82 +/- 20 to 70 +/- 22 beats min-1, P less than 0.05), in cardiac output (4.3 +/- 0.3 to 3.2 +/- 0.41 min-1, P less than 0.02, n = 5) and in systemic vascular resistances (2326 +/- 463 to 1532 +/- 442 dynes sec-1 cm.5, P less than 0.02) not present in Group 2. The reduction in right (Group 1, 8 +/- 3 to 3 +/- 1, vs. Group 2, 10 +/- 3 to 6 +/- 3 mmHg, P less than 0.005) and in left ventricular filling pressures (Group 1, 15 +/- 4 to 8 +/- 2, vs. Group 2, 18 +/- 6 to 13 +/- 5 mmHg, P less than 0.001) was more remarkable in Group 1. In this group there was also a high incidence of anterior infarction (9/12, 75%).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Sublingual↗

PubMed2001

Enhanced 99Tc(m)-MIBI SPECT detection of hibernating myocardium following the use of sub-lingual nitroglycerine.

The purpose of this study was to assess the feasibility of detecting hibernating myocardium using 99Tc(m)-MIBI SPECT imaging following the use of sublingual glyceryl trinitrate (GTN). Thirty-eight subjects were studied, five asymptomatic and 33 with a history of myocardial ischaemia or myocardial infarction (MI). The study was conducted on two separate days, both at rest, one under controlled basal conditions and the other 20 min following the sublingual administration of GTN. A total of 190 cardiac segments were qualitatively analysed and 72 segments with fixed defects were compared to the study following the use of GTN for evidence of improved radionuclide uptake. Following GTN, 73.6% of fixed segment defects showed no change in uptake, 5.5% showed probable improvement whilst in 20.8% a definite enhanced uptake was demonstrated. In 3.7% of segments, worsening of radionuclide uptake was observed.

Administration, Sublingual↗

PubMed2005

Nitric oxide increases endocervical secretion at the ovulatory phase in the female.

BACKGROUND: Uterine cervical mucus is crucial for reproduction, facilitating sperm transport and survival in certain mammals. Cholinergic autonomic nervous secretory innervation has been established, and modulation of secretion by prostaglandins and non-steroidal anti-inflammatory drugs has been postulated. It has been suggested that glandular nitric oxide (NO) production is a prerequisite for the autonomic cholinergic nervous modulation of cervical, endometrial, and the seminal vesicle secretion in the guinea pig. Most secretory genital tract cells, female as well as male, seem to display NO synthase activity. METHODS: Cervical secretion at ovulation time was studied in 10 women with regular menstruation. In an in vivo model with repeated collection of mucus samples during four 60-min periods, the amount of mucus was estimated in a control experimental series and in an experimental series following sublingual administration of the NO donor nitroglycerin. RESULTS: This nitroglycerin administration markedly increased cervical secretion, while no changes in cervical secretion were seen in the control experimental series. CONCLUSIONS: The results suggest that glandular NO production increases cervical secretion. Thus, cervical secretion may, apart from hormonal regulation, be influenced by the autonomic nervous system, and in addition, NO may be a prerequisite for this influence. This in turn may have implications on fertilization and fertility regulation.

Administration, Sublingual↗

PubMed1994

Preliminary investigation of the efficacy of sublingual verapamil in the management of acute atrial fibrillation and flutter.

The antiarrhythmic properties of sublingual verapamil were investigated in seven patients with acute fast atrial flutter (n = 2) or fibrillation (n = 5). A rapid and significant (P < 0.05) reduction in the ventricular rate was achieved in all seven patients. The ventricular rate at peak plasma verapamil concentration (+/- s.d.) was significantly slower than on admission (101.6 +/- 11.3 and 159 +/- 5.3 beats min-1 respectively, P < 0.01). The ventricular rate remained controlled for over 4 h. Sublingual verapamil was rapidly absorbed with the maximum peak plasma concentration (153.3 +/- 15.5 ng ml-1) being achieved after 1.21 +/- 0.18 h. Side-effects of sublingual verapamil were limited to one report of a bitter taste. The sublingual administration of verapamil may provide an alternative method for the control of acute fast atrial fibrillation and flutter in selected patients.

Acute Disease↗

PubMed2005

Sublingual delivery of insulin: effects of enhancers on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity.

The purposes of this study were to evaluate effects of enhancers for sublingual delivering insulin on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity in normal rats. The effects on sublingual mucosa, and aggregation states of insulin were estimated using fluorescence polarization, and circular dichroism method, respectively. The human immortalized oral epithelial cell monolayer was used for evaluating transport of insulin. Hydroxylpropyl-beta-cyclodextrin (HP-beta-CD), chitosan, polyethylene-polypropylene glycol, polyoxyethylene lauryl ether, polysorbate 80, egg lecithin, or oleic acid, was used as a penetration enhancer, respectively. The fluidity of sublingual mucosal lipid was markedly reduced by these enhancers excluding polysorbate 80, and the secondary structure of the mucosal proteins was also influenced by these enhancers. The hexamers of insulin were dissociated to monomers only by chitosan, polyoxyethylene lauryl ether, and egg lecithin. Nonetheless, plasma glucose levels in normal rats were significantly lowered after sublingual administration of insulin with an enhancer compared with those without an enhancer at the same time-point. The enhancing effects may be due to one or multiple factors: increasing the mucosal lipid fluidity, directly loosing the tight junction of epithelia, and dissociating the hexamers of insulin to monomers. Among these, the opened tight junction may correlate most with the enhancing effect in the mucosal permeability. Because the aggregates of insulin exist, the dissociation of the aggregates by an enhancer would benefit the permeability.

Administration, Sublingual↗

PubMed2004

Effect of smoking on endothelial function and wall thickness of brachial artery.

BACKGROUND: Impaired flow mediated dilatation (FMD) and increased wall thickness (WT) of the brachial artery have been associated with atherosclerosis and its risk factors. In this study we sought to determine brachial artery wall thickness in chronic smokers and the instantaneous effect of smoking on brachial artery endothelium dependent vasodilator function in smokers and non-smokers. METHOD AND RESULTS: Using a high-resolution ultrasound, WT of posterior brachial artery wall, the diameter of brachial artery at rest and during reactive hyperemia (FMD %), as well as after sublingual administration of nitroglycerine (nitroglycerine mediated dilatation (NMD) %) was measured in 20 smokers and 20 non-smokers. Wall thickness (WT) of the posterior brachial artery wall and the wall index (WI) were greater in smokers than non-smokers. The baseline brachial artery diameter was comparable in smokers and non-smokers. Flow mediated dilation (FMD) was found to be less in smokers than non-smokers. The NMD in smokers also did not differ significantly from that in non-smokers. Flow mediated dilation significantly reduced after smoking compared to baseline in both groups. However, NMD remained unchanged after smoking in both groups. CONCLUSIONS: Increased WT and impaired endothelium-dependent dilatation of brachial artery suggests that cigarette smoking disrupts vessel wall morphology long before atherosclerosis is manifest.

Administration, Sublingual↗