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Annals of Noninvasive Electrocardiology... Jan 2006It has been shown that mortality risk in patients after myocardial infarction could be estimated by heart rate turbulence (HRT), a short-term change in heart rate after...
BACKGROUND
It has been shown that mortality risk in patients after myocardial infarction could be estimated by heart rate turbulence (HRT), a short-term change in heart rate after ventricular premature beat (VPB), presumably caused by baroreceptor mechanism. We sought to determine whether pharmacological blockade with atropine, or augmentation of vagal tone with pirenzepine given in small doses would influence HRT.
METHODS
In 30 patients with normal echocardiogram, and without signs or symptoms of coronary artery disease, after electrophysiologic examination or radiofrequency ablation for supraventricular arrhythmias was completed, turbulence onset (TO) and turbulence slope (TS) in basal state, after 1.3 mg IV pirenzepine and finally, after atropine in dose of 0.04 mg/kg of body weight were compared.
RESULTS
As assessed by Friedman ANOVA test both pirenzepine and atropine caused a significant change in both TO (P < 0.01) and TS (P < 0.01). The mean basal TO of -3.6 +/- 2.9%, changed after pirenzepine to -5.99 +/- 5.6% (P < 0.01), and after atropine it changed to -3.3 +/- 18.1% (P < 0.01). The mean basal TS of 18.6 +/- 10.1 ms/R-R interval increased after pirenzepine to 26.8 +/- 19.9 ms/R-R interval (P < 0.05), and decreased after atropine to 1.2 +/- 0.8 ms/R-R interval (P < 0.01). Mean cycle length increased after pirenzepine from 706.8 +/- 106.8 to 830 +/- 151.9 ms (P < 0.01), and decreased after atropine to 454.2 +/- 58.1 ms (P < 0.01).
CONCLUSION
A conclusion could be drawn that vagomymetic manipulation with intravenous pirenzepine increases HRT; vagal blockade with atropine decreases HRT. This finding suggests that a normal vagal innervation of heart is a prerequisite for the phenomenon of HRT.
Topics: Analysis of Variance; Anti-Arrhythmia Agents; Atropine; Female; Heart Conduction System; Heart Rate; Humans; Injections, Intravenous; Male; Middle Aged; Muscarinic Antagonists; Pirenzepine; Statistics, Nonparametric; Ventricular Premature Complexes
PubMed: 16472280
DOI: 10.1111/j.1542-474X.2006.00079.x -
Anesthesiology Aug 1991The dose recommendations for atropine in anesthetized children vary, and the dose-response for heart rate has not been defined. We determined the dose-response for... (Comparative Study)
Comparative Study
The dose recommendations for atropine in anesthetized children vary, and the dose-response for heart rate has not been defined. We determined the dose-response for atropine and heart rate in 181 healthy children anesthetized with halothane and nitrous oxide. After induction of anesthesia, atropine in a dose of 5, 10, 20, 30, or 40 micrograms.kg-1 was administered by rapid intravenous infusion of each subject. The effects of atropine on heart rate, heart rhythm, and systolic blood pressure were compared among dosage groups, and a dose-response curve for peak heart rate was constructed. The effects of atropine were compared also between younger and older subjects. For the group of all 181 subjects, atropine increased heart rate in a dose-related manner up to 30 micrograms.kg-1. Fifty percent maximal response corresponded to 9 micrograms.kg-1, and 90% maximal response corresponded to 26 micrograms.kg-1. Some subjects had nonsinus supraventricular rhythms before atropine, but none had nonsinus rhythm after atropine except after the smallest dose, 5 micrograms.kg-1. Systolic blood pressure increased significantly after all doses of atropine except 5 mu.kg-1. Subjects less than 6 months old had higher control and peak heart rates than did subjects greater than or equal to 2 yr old, but the older subjects had greater change in heart rate after atropine. For subjects greater than or equal to 2 yr old, all doses of atropine produced a significant increase in heart rate. The same was true for younger subjects, less than 6 months old, except that 5 micrograms.kg-1 did not increase heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Aging; Anesthesia, Inhalation; Atropine; Blood Pressure; Child; Child, Preschool; Dose-Response Relationship, Drug; Halothane; Heart Rate; Humans; Infant; Infusions, Intravenous; Nitrous Oxide
PubMed: 1859012
DOI: 10.1097/00000542-199108000-00011 -
British Journal of Clinical Pharmacology Dec 1983Twenty-seven healthy male subjects of mean age 24.3 +/- 4.0 years and mean weight 74.9 +/- 9.1 kg took part in an investigation to assess the most suitable correction...
Twenty-seven healthy male subjects of mean age 24.3 +/- 4.0 years and mean weight 74.9 +/- 9.1 kg took part in an investigation to assess the most suitable correction for the QT interval as a function of cardiac cycle length. 547 sets of data points were generated. Atropine 0.6, 1.2 and 1.8 mg, and hyoscine 0.4 and 0.8 mg, and exercise on a bicycle ergometer at power levels of 50-250 watts together with post-exercise values were employed to obtain a range of heart rates. Simultaneous measurement of cardiac output and total peripheral resistance were made. It was found that the traditional square root formula gave an unsatisfactory correction for the QT for supine subjects following atropine and hyoscine. The formula K = QT/RRN was linearized and fitted to the data by the least squares method and gave a best fit correction with N = 0.35, which is close to the cube root correction of Fridericia (1920). Neither stroke volume nor total peripheral resistance were found to provide a further enhancement of the correction. The relationship between QT and cycle length following the exercise protocol was found to be best represented by Bazett's correction but the complex changes in the QT produced by exercise were noted. These findings support the suggestion that either the cube root correction or the best fit correction with N = 0.35 provides a better correction factor than the traditional square root correction for the QT interval in clinical pharmacology experiments for data generated in resting patients.
Topics: Adult; Atropine; Electrocardiography; Humans; Male; Mathematics; Physical Exertion; Posture; Scopolamine; Stroke Volume
PubMed: 6661344
DOI: 10.1111/j.1365-2125.1983.tb02230.x -
British Medical Journal Oct 1979
Topics: Anxiety; Atropine; Female; Humans; Intrauterine Devices; Shock
PubMed: 509150
DOI: 10.1136/bmj.2.6196.1001-b -
PloS One 2019It is essential to elucidate drug distribution in the ocular tissues and drug transit in the eye for ophthalmic pharmaceutical manufacturers. Atropine is a reversible...
MALDI imaging mass spectrometry revealed atropine distribution in the ocular tissues and its transit from anterior to posterior regions in the whole-eye of rabbit after topical administration.
It is essential to elucidate drug distribution in the ocular tissues and drug transit in the eye for ophthalmic pharmaceutical manufacturers. Atropine is a reversible muscarinic receptor used to treat various diseases. However, its distribution in ocular tissues is still incompletely understood. Matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) evaluates drug distribution in biological samples. However, there have been few investigations of drug distribution in ocular tissues, including whole-eye segments. In the present study, we explored the spatial distribution of atropine in the whole-eye segment by MALDI-IMS, and then evaluated the changes in atropine level along the anterior-posterior and superior-inferior axes. A 1% atropine solution was administered to a rabbit and after 30 min, its eye was enucleated, sectioned, and analyzed by MALDI-IMS. Atropine accumulated primarily in the tear menisci but was found at substantially lower concentrations in the tissue surrounding the conjunctival sacs. Relative differences in atropine levels between the anterior and posterior regions provided insights into the post-instillation behavior of atropine. Atropine signal intensities differed among corneal layers and between the superior and inferior eyeball regions. Differences in signal intensity among tissues indicated that the drug migrated to the posterior regions via a periocular-scleral route. Line scan analysis elucidated atropine transit from the anterior to the posterior region. This information is useful for atropine delivery in the ocular tissues and indicates that MALDI-IMS is effective for revealing drug distribution in whole-eye sections.
Topics: Administration, Topical; Animals; Atropine; Chromatography, High Pressure Liquid; Eye; Male; Rabbits; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tissue Distribution
PubMed: 30682156
DOI: 10.1371/journal.pone.0211376 -
Medicine Nov 2020Topical atropine has become a mainstream treatment of myopia throughout East and Southeast Asia, but it is uncertain whether long-term topical atropine therapy induces...
Topical atropine has become a mainstream treatment of myopia throughout East and Southeast Asia, but it is uncertain whether long-term topical atropine therapy induces intraocular pressure (IOP) elevation and subsequent development of glaucoma. We then prospectively examined the effects of long-term atropine treatment on IOP.Our case series collected 186 myopic children who were younger than 16 years of age. Complete ocular examination data, IOP and refractive status measurements beginning in 2008 were collected for all participants. Participants were divided into two groups: 121 children who received atropine therapy at various concentrations were classified as the treated group, whereas 65 children who did not receive atropine therapy were classified as the untreated (reference) group. In the treated group, clinicians prescribed different concentrations of atropine eye drops according to their discretion with regard to the severity of myopia on each visit of the patient. We then calculated the cumulative dose of atropine therapy from 2008 to the patients' last follow-up in 2009. Furthermore, the treated group was then further divided into low- and high-refractive-error groups of nearly equal size for further analysis.There were no significant differences for the baseline refractive errors and IOPs between the treated and untreated groups. Both the low- and high-cumulative atropine dosage subgroups showed significantly lower myopic progression than the untreated group, but there was no significant difference between the two subgroups in terms of different cumulative dosages. All groups, including the untreated group, showed an increase of mean IOP at the last follow-up, but both low- and high-cumulative atropine dosage subgroups experienced a smaller increase of IOP. The mean IOP of all atropine-treated groups showed no significant increase in either low- or high-refractive-error eyes.This study revealed that topical atropine eye drops do not induce ocular hypertension and are effective for slowing the progression of myopia. The treatment effects are not correlated with the cumulative atropine dosages.
Topics: Atropine; Case-Control Studies; Child; Female; Glaucoma; Humans; Intraocular Pressure; Longitudinal Studies; Male; Muscarinic Antagonists; Myopia, Degenerative; Ophthalmic Solutions; Prospective Studies; Tonometry, Ocular
PubMed: 33235063
DOI: 10.1097/MD.0000000000022745 -
Vision Research Jan 2024The effect of topical 1 % atropine on the diurnal rhythms of the human eye was investigated. Participants wore an activity monitor on Days 1-7. A set of measures...
The effect of topical 1 % atropine on the diurnal rhythms of the human eye was investigated. Participants wore an activity monitor on Days 1-7. A set of measures (epochs) encompassing intraocular pressure (IOP), ocular biometry, and retinal imaging were obtained on Day 7 (baseline), followed by eight epochs on Day 8, and one on Day 9 from both eyes of healthy participants (n = 22, 19-25 years). The sleep time of participants (collected via actigraphy) was used as a reference in scheduling epochs. Topical 1 % atropine was instilled in the dominant eye on Day 8, 2 h after habitual wake time, using the fellow eye as control (paired-eye design). Sinusoids with a 24-h period were fitted to the data, and a non-linear mixed-effects model was used to estimate rhythmic statistics. There were no interocular differences in any of the measured parameters at baseline. Comparing pre- versus post-atropine in treated eyes revealed lower IOP, deeper anterior chamber (ACD), decreased crystalline lens thickness and shorter axial length (AL). The same trends were observed when comparing atropine-treated versus fellow control eyes, except for IOP and AL (no differences). Both atropine-treated and fellow control eyes showed significant diurnal variations in all ocular parameters, with atropine-treated eyes revealing larger AL and retinal thickness amplitudes, smaller vitreous chamber depth (VCD) amplitudes, and a significant phase advancement for ACD and VCD. There were no interocular differences in choroidal thickness rhythms. In conclusion, while ocular diurnal rhythms persisted after instillation of 1 % atropine, many rhythmic parameters were altered.
Topics: Humans; Atropine; Intraocular Pressure; Choroid; Retina; Circadian Rhythm; Biometry; Axial Length, Eye
PubMed: 38065032
DOI: 10.1016/j.visres.2023.108341 -
Food Research International (Ottawa,... Jul 2024Tropane alkaloids (TAs) are secondary metabolites from weeds that can contaminate cereals and vegetables during harvest. Due to their toxicity, the Regulation (EC)...
Tropane alkaloids (TAs) are secondary metabolites from weeds that can contaminate cereals and vegetables during harvest. Due to their toxicity, the Regulation (EC) 2023/915 sets maximum levels for atropine and scopolamine in cereal-based foods for infants containing millet, sorghum, buckwheat or their derived products. The aim of this study was to evaluate the effect of pH and temperature on the stability of TAs, as possible parameters in thermal processing to mitigate this chemical hazard in cereal-based infant food. The effect of pH (4 and 7) and temperature (80 °C and 100 °C) was assessed in buffer solutions. Also, treatment at 180 °C was performed in spiked and naturally incurred millet flour to assess the effect of high temperature, simulating cooking or drying, on the stability of TAs in the cereal matrix. The fate of 24 TAs was assessed by UHPLC-MS/MS. TAs showed high thermostability, although it was variable depending on the specific compound, pH, temperature and treatment time. In buffer solutions, higher degradation was found at 100 °C and pH 7. In spiked millet flour at 180 °C for 10 min, scopolamine and atropine contents decreased by 25 % and 22 %, similarly to other TAs which also showed a slow thermal degradation. Atropine, scopolamine, anisodamine, norscopolamine, scopine and scopoline were found in naturally contaminated millet flour. Interestingly, naturally incurred atropine was more thermostable than when spiked, showing a protective effect of the cereal matrix on TAs degradation. The present results highlight the need for an accurate monitorization of TAs in raw materials, as this chemical hazard may remain in infant cereal-based food even after intense thermal processing.
Topics: Edible Grain; Hydrogen-Ion Concentration; Infant Food; Tandem Mass Spectrometry; Food Contamination; Tropanes; Temperature; Alkaloids; Humans; Food Handling; Hot Temperature; Atropine; Infant; Chromatography, High Pressure Liquid
PubMed: 38823829
DOI: 10.1016/j.foodres.2024.114439 -
Eye (London, England) Jul 2016PurposeRandomized controlled trials have shown the efficacy of atropine for progressive myopia, and this treatment has become the preferred pattern for this condition in...
PurposeRandomized controlled trials have shown the efficacy of atropine for progressive myopia, and this treatment has become the preferred pattern for this condition in Taiwan. This study explores the effectiveness of atropine 0.5% treatment for progressive high myopia and adherence to therapy in a non-Asian country.MethodsAn effectiveness study was performed in Rotterdam, the Netherlands. Overall 77 children (mean age 10.3 years±2.3), of European (n=53), Asian (n=18), and African (n=6) descent with progressive myopia were prescribed atropine 0.5% eye drops daily. Both parents and children filled in a questionnaire regarding adverse events and adherence to therapy. A standardized eye examination including cycloplegic refraction and axial length was performed at baseline and 1, 4, and 12 months after initiation of therapy.ResultsMean spherical equivalent at baseline was -6.6D (±3.3). The majority (60/77, 78%) of children adhered to atropine treatment for 12 months; 11 of the 17 children who discontinued therapy did so within 1 month after the start of therapy. The most prominent reported adverse events were photophobia (72%), followed by reading problems (38%), and headaches (22%). The progression rate of spherical equivalent before treatment (-1.0D/year±0.7) diminished substantially during treatment (-0.1D/year±0.7) compared to those who ceased therapy (-0.5D/year±0.6; P=0.03).ConclusionsDespite the relatively high occurrence of adverse events, our study shows that atropine can be an effective and sustainable treatment for progressive high myopia in Europeans.
Topics: Administration, Topical; Adolescent; Atropine; Axial Length, Eye; Child; Disease Progression; Female; Humans; Male; Medication Adherence; Muscarinic Antagonists; Myopia, Degenerative; Netherlands; Ophthalmic Solutions; Refraction, Ocular; Treatment Outcome; White People
PubMed: 27101751
DOI: 10.1038/eye.2016.78 -
Molecules (Basel, Switzerland) Sep 2021In rats with polycystic ovary syndrome (PCOS) induced by injection of estradiol valerate (EV), unilateral or bilateral section of the vagus nerve restores ovulatory...
In rats with polycystic ovary syndrome (PCOS) induced by injection of estradiol valerate (EV), unilateral or bilateral section of the vagus nerve restores ovulatory function in 75% of animals, suggesting that the vagus nerve participates in the development of PCOS. Since the vagus nerve is a mixed nerve through which mainly cholinergic-type information passes, the objective of the present study was to analyze whether acetylcholine (ACh) is involved in the development of PCOS. Ten-day-old rats were injected with 2.0 mg EV, and at 60 days of age, they were microinjected on the day of diestrus in the bursa of the left or right ovary with 100 or 700 mg/kg of ovarian weight atropine, a blocker of muscarinic receptors, and sacrificed for histopathological examination after the surgery. Animals with PCOS microinjected with 100 mg of atropine showed a lack of ovulation, lower serum concentrations of progesterone and testosterone, and cysts. Histology of the ovaries of animals microinjected with 700 mg of atropine showed corpus luteum and follicles at different stages of development, which was accompanied by a lower concentration of progesterone and testosterone. These results allow us to suggest that in animals with PCOS, ACh, which passes through parasympathetic innervation, is an important component in the persistence and development of the pathophysiology.
Topics: Animals; Atropine; Estradiol; Female; Ovulation; Polycystic Ovary Syndrome; Progesterone; Rats
PubMed: 34576975
DOI: 10.3390/molecules26185506