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1.
Pharmacol Biochem Behav ; 241: 173793, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38823543

ABSTRACT

OBJECTIVE: Caffeine and modafinil are used to reverse effects of sleep deprivation. Nicotinic alpha-7 receptor and AMPA receptor positive allosteric modulators (PAM) are also potential substances in this context. Our objective is to evaluate the effects of caffeine, modafinil, AVL-3288 (nicotinic alpha-7 PAM) and CX516 (AMPA receptor PAM) on cognition and mood in a model of sleep deprivation. METHOD: Modified multiple platform model is used to sleep-deprive mice for 24 days, for 8 h/day. Vehicle, Modafinil (40 mg/kg), Caffeine (5 mg/kg), CX516 (10 mg/kg), and AVL3288 (1 mg/kg) were administered intraperitoneally daily. A cognitive test battery was applied every six days for four times. The battery that included elevated plus maze, novel object recognition, and sucrose preference tests was administered on consecutive days. RESULTS: Sleep deprivation decreased novel object recognition skill, but no significant difference was found in anxiety and depressive mood. Caffeine administration decreased anxiety-like behavior in short term, but this effect disappeared in chronic administration. Caffeine administration increased memory performance in chronic period. AVL group showed better memory performance in short term, but this effect disappeared in the rest of experiment. Although, in the modafinil group, no significant change in mood and memory was observed, anhedonia was observed in the chronic period in vehicle, caffeine and modafinil groups, but not in AVL-3288 and CX-516 groups. CONCLUSION: Caffeine has anxiolytic effect in acute administration. The improvement of memory in chronic period may be associated with the neuroprotective effects of caffeine. AVL-3288 had a short-term positive effect on memory, but tolerance to these effects developed over time. Furthermore, no anhedonia was observed in AVL-3288 and CX516 groups in contrast to vehicle, caffeine and modafinil groups. This indicates that AVL-3288 and CX516 may show protective effect against depression.


Subject(s)
Affect , Caffeine , Cognition , Modafinil , Sleep Deprivation , Animals , Sleep Deprivation/psychology , Sleep Deprivation/drug therapy , Sleep Deprivation/complications , Modafinil/pharmacology , Modafinil/administration & dosage , Mice , Male , Cognition/drug effects , Caffeine/pharmacology , Caffeine/administration & dosage , Affect/drug effects , Disease Models, Animal , Central Nervous System Stimulants/pharmacology , Central Nervous System Stimulants/administration & dosage , Benzhydryl Compounds/pharmacology , Benzhydryl Compounds/administration & dosage , Time Factors , Anxiety/drug therapy
3.
Eur J Clin Pharmacol ; 80(5): 729-735, 2024 May.
Article in English | MEDLINE | ID: mdl-38353690

ABSTRACT

PURPOSE: Artificial intelligence, specifically large language models such as ChatGPT, offers valuable potential benefits in question (item) writing. This study aimed to determine the feasibility of generating case-based multiple-choice questions using ChatGPT in terms of item difficulty and discrimination levels. METHODS: This study involved 99 fourth-year medical students who participated in a rational pharmacotherapy clerkship carried out based-on the WHO 6-Step Model. In response to a prompt that we provided, ChatGPT generated ten case-based multiple-choice questions on hypertension. Following an expert panel, two of these multiple-choice questions were incorporated into a medical school exam without making any changes in the questions. Based on the administration of the test, we evaluated their psychometric properties, including item difficulty, item discrimination (point-biserial correlation), and functionality of the options. RESULTS: Both questions exhibited acceptable levels of point-biserial correlation, which is higher than the threshold of 0.30 (0.41 and 0.39). However, one question had three non-functional options (options chosen by fewer than 5% of the exam participants) while the other question had none. CONCLUSIONS: The findings showed that the questions can effectively differentiate between students who perform at high and low levels, which also point out the potential of ChatGPT as an artificial intelligence tool in test development. Future studies may use the prompt to generate items in order for enhancing the external validity of the results by gathering data from diverse institutions and settings.


Subject(s)
Hypertension , Students, Medical , Humans , Artificial Intelligence , Schools, Medical
4.
Anatol J Cardiol ; 27(6): 328-338, 2023 06.
Article in English | MEDLINE | ID: mdl-37257006

ABSTRACT

BACKGROUND: Elderly comprises a specific group due to possible alterations in the effects of drugs and comorbidities. We aimed to identify for the first time the characteristics and rates regarding the inappropriate prescriptions of cardiovascular system medications in the geriatric age group in Turkey. METHODS: Cardiovascular system medications prescribed electronically by family physicians to patients aged 65 and over, in the years 2015 and 2016, were obtained through Prescription Information System administered by the Ministry of Health. Evaluation of potentially inappropriate prescriptions was done according to the 'Beers Criteria 2015 update.' Prescription rates for each group were evaluated under sub-breakdowns for the specialty of family physicians, gender, age groups, and 'Nomenclature of Territorial Units for Statistics' regions. RESULTS: Approximately 65 million prescriptions were evaluated. The rate of potentially inappropriate cardiovascular medication prescribing was 0.33%. This raised to 11.56% when 'drugs to be used with caution' were included. It was observed that potentially inappropriate drugs have been prescribed more by specialist family physicians. The most frequently prescribed potentially inappropriate drugs were doxazosin in the diagnosis of hypertension and methyldopa regardless of indication. Diclofenac-warfarin was the most commonly prescribed concomitant drug use in the potentially clinically important drug-drug interactions group. The rate of potentially inappropriate drug prescribing was higher in males and in aged 80 years and older. CONCLUSIONS: This pharmacoepidemiological study draws attention to potentially inappropriate cardiovascular system drugs prescribed in primary care settings to the elderly. The rate of potentially inappropriate cardiovascular system drug prescribed was found to be very low in Turkey.


Subject(s)
Cardiovascular System , Medication Errors , Aged , Humans , Male , Drug Prescriptions , Potentially Inappropriate Medication List , Turkey , Aged, 80 and over , Female
5.
J Clin Res Pediatr Endocrinol ; 15(2): 145-153, 2023 05 29.
Article in English | MEDLINE | ID: mdl-36597761

ABSTRACT

Objective: This study was planned to determine the effects of carob use on puberty because of the observation of early puberty or pubertal variants due to the long-term use of carob in our clinic. Methods: Forty-eight Wistar albino rats, on postnatal day 21, were assigned into two groups female (n=24) and male (n=24). Groups were divided into four groups Control, and Carob-150, Carob-300, and Carob-600. Ceratonia siliqua L. extract was given to rats in a 0.5% carboxymethylcellulose (CMC) solution. CMC (0.5%) was given to the control, Ceratonia siliqua L. extract was given 150 mg/kg/day to the Carob-150, 300 mg/kg/day to the Carob-300, 600 mg/kg/day to the Carob-600 by oral gavage. The treatments were performed once daily until the first sign of puberty. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, total testosterone, leptin, glutathione, glutathione peroxidase (GPx), and malondialdehyde were measured by commercial rat-specific ELISA kits. Testis, uterus and ovarian tissue were examined histologically. Results: The median time of preputial separation in male rats was 38th, 31st, 31st, and 31st days in the Control, Carob-150, Carob-300, and Carob-600 groups, respectively (p=0.004). The median day of vaginal opening day was the 39th, 31st, 34th, and 31st days in the Control, Carob-150, Carob-300, and Carob-600 groups, respectively (p=0.059). FSH, LH, testosterone (male), estradiol (female) and leptin levels of the groups were similar. However, GPx levels were higher in male and female animals given C. siliqua extract compared to the Control (male p=0.001 and female p=0.008). Testicular and ovarian tissues were concordant with the pubertal period in all groups. As the dose of Ceratonia siliqua extract increased, it induced spermatogenesis and spermiogenesis, causing abnormal changes, such as ondulation in the basement membrane, capillary dilatation, and increased congestion in males. In females, edema in the medulla gradually increased with increased dosage, and granulosa cell connections were separated in Carob-300 and Carob-600 groups. Conclusion: This study demonstrated that C. siliqua caused early puberty and increased spermiogenesis and folliculogenesis. Antioxidant mechanisms were impaired with increasing dose, possibly leading to tissue damage at high doses.


Subject(s)
Fabaceae , Fruit , Female , Animals , Rats , Male , Humans , Leptin , Rats, Wistar , Plant Extracts/pharmacology , Puberty
6.
Eur J Clin Pharmacol ; 79(3): 341-348, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36622428

ABSTRACT

AIM: This study aimed to reveal the current status of the literature on rational prescribing training in undergraduate medical education. METHODS: This study followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. An online search using 50 keywords in four databases was performed to access the studies published between 2008 and 2020. Specific features of the training such as aims or objectives of teaching, methods or model, and evaluation of effectiveness were extracted. Kirkpatrick levels were used to evaluate the effectiveness of teaching. RESULTS: Of 74 studies included in the full review, 16 (21.6%) of them reported the use of WHO 6-Step Model for Rational Prescribing in their educational interventions. In terms of effectiveness, only two of the studies investigated changes in learner behavior in the context for which they are being trained, and only one study showed the effect of training on patient outcomes. CONCLUSION: The evidence on the effectiveness of rational prescribing training has been presented mostly by using student satisfaction surveys and test of knowledge and skills. A higher level of evidence such as patient outcomes of the training needs to be reported.


Subject(s)
Education, Medical, Undergraduate , Humans , Clinical Competence
7.
Psychiatry Investig ; 15(3): 313-319, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29475241

ABSTRACT

OBJECTIVE: Citalopram (CITA) is a widely used and well-tolerated selective serotonin reuptake inhibitor. The aim of the study was to evaluate the possible influences of serum concentrations of CITA and its major metabolite n-desmethylcitalopram (NDCITA) on the efficacy and tolerability of CITA in patients with major depressive disorder. METHODS: The study included 46 outpatients with major depressive disorder who received CITA. The efficacy and tolerability were assessed for 6 weeks. Serum CITA and NDCITA levels were measured at the 4th week. RESULTS: The HDRS17 total scores of the patients with high NDCITA and CITA & NDCITA concentrations showed a more significant reduction compared to the patients with expected and low serum NDCITA and CITA & NDCITA concentrations. However, we did not observe a correlation between the serum concentrations and the side effects of CITA, NDCITA, and CITA & NDCITA. CONCLUSION: Our results suggested the potential contribution of NDCITA to the antidepressant effect of CITA. Further studies involving larger clinical samples are required to confirm the impact of serum NDCITA concentrations on the efficacy of CITA.

8.
Nord J Psychiatry ; 71(3): 230-237, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28079463

ABSTRACT

BACKGROUND: The pharmacokinetics and the pharmacodynamics of antidepressants show large inter-individual variations which result in unpredictable clinical responses. AIM: The aim of the study was to examine the effect of ABCB1 polymorphisms and the serum concentrations on the efficacy and tolerability of venlafaxine in patients with major depressive disorder (MDD). METHODS: Fifty-two outpatients who met the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) criteria for MDD were recruited for the study. The severity of depression was assessed using the 17-item Hamilton Rating Scale for Depression scale (HDRS17) and tolerability was assessed based on a query regarding side-effects for 6 weeks. The ABCB1 C3435T/A and G2677T/A polymorphisms were genotyped by PCR/RFLP and steady-state serum venlafaxine concentrations were measured by high-performance liquid chromatography. RESULTS: Patients with the TT genotype for the C3435T and the TT/TA genotype for the G2677T/A polymorphism showed significantly higher frequencies in venlafaxine-induced akathisia. This relationship was not observed for efficacy. As regards serum venlafaxine concentrations, patient groups showed no significant differences in efficacy and tolerability. CONCLUSION: The results suggest that individuals with the TT-TT/TA genotypes for the C3435T-G2677T/A polymorphisms of ABCB1 may be pre-disposed to a risk of akathisia.


Subject(s)
Akathisia, Drug-Induced/genetics , Depressive Disorder, Major/drug therapy , Depressive Disorder, Major/genetics , Serotonin and Noradrenaline Reuptake Inhibitors/blood , Venlafaxine Hydrochloride/blood , ATP Binding Cassette Transporter, Subfamily B/genetics , Adult , Aged , Female , Humans , Male , Middle Aged , Serotonin and Noradrenaline Reuptake Inhibitors/administration & dosage , Serotonin and Noradrenaline Reuptake Inhibitors/adverse effects , Venlafaxine Hydrochloride/administration & dosage , Venlafaxine Hydrochloride/adverse effects , Young Adult
9.
Pharmacol Rep ; 66(2): 235-8, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24911075

ABSTRACT

BACKGROUND: The ATP-binding cassette sub-family B member 1 (ABCB1) gene, which encodes the p-glycoprotein at the blood-brain barrier, is investigated for patients' susceptibility to major depressive disorder (MDD) and their therapeutic response to antidepressants. However, there is an inconsistency between the studies of different ethnic groups. The current study aimed to determine the potential correlations of the ABCB1 gene C3435T polymorphism with the susceptibility to MDD and the therapeutic response to citalopram in a Turkish population. METHODS: Fifty-four patients with MDD who received citalopram and 70 controls from the Turkish population were genotyped for ABCB1 C3435T polymorphism. To assess the therapeutic response to citalopram, all patients were rated baseline, first, second, fourth and sixth weeks according to the 17-item Hamilton Rating Scale for Depression (HAMD-17). RESULTS: There was a significant correlation between the patient and control groups for ABCB1 C3435T polymorphism. Distribution of CC genotype and C allele frequency were higher in the patients than in the control group (p = 0.006, p = 0.020, respectively). However, no correlation between ABCB1 C3435T polymorphism and a therapeutic response to citalopram was observed. CONCLUSION: Our results suggested that C3435T polymorphism in the ABCB1 gene may be an indicator of the susceptibility to major depression, without a likely treatment response to citalopram in a Turkish population. These findings should be replicated in studies on larger patient groups with different ethnicities.


Subject(s)
Antidepressive Agents, Second-Generation/therapeutic use , Citalopram/therapeutic use , Depressive Disorder, Major/drug therapy , Depressive Disorder, Major/genetics , Genetic Predisposition to Disease , Polymorphism, Genetic , ATP Binding Cassette Transporter, Subfamily B/genetics , Adult , Female , Genotype , Humans , Male , Middle Aged
10.
Pharmacogenomics ; 10(5): 769-78, 2009 May.
Article in English | MEDLINE | ID: mdl-19450128

ABSTRACT

AIMS: To study the variation in CYP1A2 activity in relation to smoking, gender, age and CYP1A2 polymorphisms. MATERIALS & METHODS: CYP1A2 activity was determined by plasma paraxanthine:caffeine ratio (17X:137X) 4 h after the intake of a standardized cup of coffee in 146 Turkish healthy volunteers. Seven CYP1A2 polymorphisms (-3860G>A, -3113G>A, -2467del/T, -739T>G, -729C>T, -163C>A and 5347T>C) were analyzed. RESULTS: The 17X:137X ratios were increased in smokers (p < 0.0001) and tended to be higher in men both among nonsmokers (p = 0.051) and smokers (p = 0.064). Age-related differences were observed only among nonsmoking women (p = 0.024). The -163C>A polymorphism correlated with 17X:137X ratios only in smokers (p = 0.006). Furthermore, increased 17X:137X ratios were observed in CYP1A2 haplotype H4 (-3860G, -3113G, -2467del, -739T, -729C, -163A and 5347T) carriers in the overall study population (p = 0.026). Multiple regression analyses including smoking, gender, -163C>A genotype and age revealed a significant influence of smoking (p < 0.0001) and gender (p = 0.002) in the overall study population. However, in nonsmokers only the influence of gender remained significant (p = 0.021), while in smokers the influence of the -163C>A genotype held the statistical significance (p = 0.019). The influence of haplotype H4 remained significant (p = 0.028) in the overall study population in similar analyses. CONCLUSION: Smoking has the strongest impact on CYP1A2 activity, while gender and haplotype H4 showed marginal effects. The influence of the -163C>A polymorphism on CYP1A2 activity in smokers suggests an effect on the inducibility of the enzyme.


Subject(s)
Cytochrome P-450 CYP1A2/genetics , Polymorphism, Genetic , Polymorphism, Single Nucleotide , Smoking/genetics , Age Factors , Caffeine/blood , Cytochrome P-450 CYP1A2/biosynthesis , Cytochrome P-450 CYP1A2/metabolism , Enzyme Induction , Female , Genetic Variation , Genotype , Humans , Linkage Disequilibrium , Male , Reference Values , Sequence Deletion , Smoking/blood , Theophylline/blood , Turkey
11.
Cell Biol Int ; 31(10): 1144-9, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17482482

ABSTRACT

Ionizing radiation is widely used for the treatment of solid tumors and it is thought to act by directly targeting tumor clonogens, also known as stem cells. Apoptosis is a genetically programmed mechanism of cell death often characterized by internucleosomal DNA cleavage. Although it has been previously shown that lymphocytes readily undergo apoptosis in patients receiving anticancer drugs or treatment with ionizing radiation, this is the first study to investigate the influence of radiotherapy and melatonin on apoptosis in rat lymphocytes at two different times of the day. Melatonin, a free radical scavenger, is an endogenous neurohormone predominantly synthesized in and secreted by the pineal gland. It has been shown that melatonin inhibits apoptosis in normal cells but it increases the rate of apoptosis in various cancer cells. Therefore, in the present study, the effect of melatonin on apoptosis in cultured lymphocytes was studied after total body irradiation (TBI) was given to rats in the morning (1 HALO) or evening (13 HALO) with morphological and DNA fragmentation analysis. Two-way analysis of variance (ANOVA) revealed that radiation increased the rate of apoptosis in rat lymphocytes after TBI, and melatonin treatment did not reduce the rate of apoptosis after TBI at either time point. We conclude that the lack of an effect of melatonin on the apoptosis rate in rat lymphocytes might be due to the dose-dependent effect of melatonin, the time course of apoptosis investigated, or the cell type in which apoptosis was examined.


Subject(s)
Antioxidants/pharmacology , Apoptosis/drug effects , Apoptosis/radiation effects , Lymphocytes/drug effects , Lymphocytes/radiation effects , Melatonin/pharmacology , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Gamma Rays , Male , Rats , Rats, Wistar , Time Factors , Whole-Body Irradiation
12.
Chronobiol Int ; 20(2): 337-49, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12723889

ABSTRACT

Coronary artery bypass grafting surgery (CABGS) is done to reperfuse the ischemic myocardium of coronary disease patients. This study was designed to analyze the circadian rhythm characteristics of blood pressure (BP) and heart rate (HR) of patients before and after CABGS. Fifty-one patients undergoing elective CABGS were studied; 21 patients received one, 12 two and 18 three or more grafts. BP was monitored for 24h before and after CABGS while patients were recumbent in the hospital. Systolic (S) and diastolic (D) BP and HR were assessed every 30 min. Of the 51 patients, 37 (73%) had nondipper 24h BP patterns (nocturnal decline in BP < 10% of daytime mean level) in the preoperative baseline assessment. The peak and MESOR (rhythm-adjusted 24h mean) values of the circadian rhythm in SBP, DBP, and pulse pressure (PP) significantly declined following surgery, while HR and rate-pressure product (RPP = SBP x HR) markedly increased. The double amplitude (peak-to-trough variation) of the circadian rhythm in SBP and DBP was significantly reduced postoperatively, and that of the rhythm in HR and RPP significantly increased. The slopes of the morning rise and evening dip in the 24h SBP profile were reduced significantly after bypass grafting. The corresponding slopes of the HR profile, in contrast, were markedly increased.


Subject(s)
Blood Pressure/physiology , Circadian Rhythm/physiology , Coronary Artery Bypass , Heart Rate/physiology , Adult , Aged , Diastole , Female , Humans , Male , Middle Aged , Myocardial Ischemia/physiopathology , Myocardial Ischemia/surgery , Systole
13.
J Med Chem ; 46(5): 794-809, 2003 Feb 27.
Article in English | MEDLINE | ID: mdl-12593659

ABSTRACT

The current study describes the synthesis and biological evaluation of a novel series of 2-amino-3-naphthoylthiophenes, with variable modifications at the 4- and 5-position of the thiophene as well as the naphthoyl ring. Allosteric enhancer activity was measured in several ways: (1) evaluating the effect on forskolin-stimulated cAMP accumulation in the presence of an A(1)-adenosine agonist (CPA) in Chinese hamster ovary (CHO) cells expressing the cloned human A(1)-adenosine receptor (hA(1)AR); (2) ability of these compounds to displace the binding of [(3)H]DPCPX, [(3)H]ZM 241385, and [(3)H]MRE 3008F20 to the ligand binding site of CHO cells expressing the hA(1), hA(2A), and hA(3) adenosine receptors, respectively; (3) effect on the binding of [(3)H]CCPA to membranes from CHO cells expressing hA(1)AR, to rat brain and human cortex membrane preparations containing native adenosine A(1) receptors; (4) kinetics of the dissociation of [(3)H]CCPA from CHO-hA1 membranes. The pharmacological assays compared the various activities to that of the reference compound PD 81,723 (compound 1). Several compounds appeared to be better than PD 81,723 to enhance the effect of CPA (and thus reduce cAMP content) in the CHO:hA(1) assay. The effect of these compounds at a concentration of 10 microM was slightly greater than that of the same concentration of the PD 81,723 and substantially greater than that of PD 81,723 when responses to 1 microM of each compound were compared. These include compounds 23, 25-29, 31-34, 38, 39, 43, and 58. Cycloalkylthiophenes tended to be more potent then their 4,5-dimethyl analogues, and in the series of cycloalkylthiophenes, tetrahydrobenzo[b]thiophene derivatives appeared to be more potent than the dihydrocyclopentadien[b]thiophene counterparts. Some of the most potent compounds were tested at a concentration of 10 microM for their affinity as competitors to the antagonist binding site of CHO cells expressing hA(1), hA(2A), and hA(3) adenosine receptors. None inhibited binding at the hA(2A)AR, but most of them inhibited binding to the hA(1)AR to varying extents (0-19%) as well as to the hA(3)AR to a substantial degree (0-57%). At a concentration of 10 microM, the compounds 31, 34, 37, 38, and 39 were more active than PD 81,723 to increase the binding of [(3)H]CCPA to CHO:hA(1), human brain and rat cortex membranes. Compound 37 was the most active compound increasing the binding to CHO:hA(1), human brain, and rat cortex membranes by 149, 43, and 27%, respectively (51, 15, and 22%, respectively, for PD 81,723). A good correlation was found between the increments [(3)H]CCPA binding to A(1) receptors expressed in different systems. Unlike the effect on agonist binding, the tested compounds did not increase the binding of the antagonist [(3)H]DPCPX on hCHO-A(1) membranes. Ligand dissociation studies revealed that two compounds (22 and 39) were more potent than 1 to slow the dissociation of [(3)H]CCPA from CHO:hA(1)AR membranes. No clear-cut structure-activity relationship can be observed based on data from the functional assay, but we have identified several compounds, in particular 37 and 39, which appeared to be more potent than 1 and that may be selected for further development.


Subject(s)
Naphthalenes/chemical synthesis , Receptors, Purinergic P1/drug effects , Thiophenes/chemical synthesis , Allosteric Regulation , Animals , Binding, Competitive , Brain/metabolism , CHO Cells , Cricetinae , Cyclic AMP/biosynthesis , Humans , In Vitro Techniques , Membranes , Naphthalenes/chemistry , Naphthalenes/pharmacology , Radioligand Assay , Rats , Receptors, Purinergic P1/metabolism , Structure-Activity Relationship , Thiophenes/chemistry , Thiophenes/pharmacology
14.
Hypertension ; 40(6): 909-13, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12468578

ABSTRACT

A2A adenosine receptors inhibit neutrophil adhesion and superoxide anion generation. The aim of the present study was to evaluate the effect of antihypertensive treatment with doxazosin or propranolol on the binding and functional parameters of A2A adenosine receptors of lymphocytes and neutrophils in essential hypertensive patients. Two groups of previously untreated, essential hypertensive patients were studied. The mean affinity (K(d)) and density (B(max)) of adenosine receptors, by the A2A selective radioligand [3H]-ZM-241385 binding assays, and EC50, by cAMP assays, were obtained first on no medication and a second time after treatment for up to 13 weeks with doxazosin (13 patients) or propranolol (8 patients). A third group of 15 healthy normotensive volunteers matched by age, sex, and body mass index was used as a control. Binding and functional parameters of the A2A adenosine receptors were significantly higher in the 2 hypertensive groups than in controls (P always <0.0001), both in lymphocyte and neutrophil membranes. After treatment with propranolol, the binding parameters did not change significantly, whereas after treatment with doxazosin, K(d), B(max), and EC50 values returned to control levels. In never-treated essential hypertensive patients, lower affinity, higher density, and impaired function of A2A adenosine receptors are present. The binding and functional parameters of A2A adenosine receptors appear to be normalized after treatment with doxazosin but not with propranolol.


Subject(s)
Antihypertensive Agents/pharmacology , Doxazosin/pharmacology , Hypertension/drug therapy , Propranolol/pharmacology , Receptors, Purinergic P1/drug effects , Adenosine-5'-(N-ethylcarboxamide)/pharmacology , Adult , Antihypertensive Agents/therapeutic use , Binding, Competitive/drug effects , Blood Pressure/drug effects , Body Mass Index , Cyclic AMP/analysis , Cyclic AMP/metabolism , Diastole , Doxazosin/therapeutic use , Female , Humans , Hypertension/metabolism , Lymphocytes/metabolism , Male , Middle Aged , Neutrophils/metabolism , Propranolol/therapeutic use , Radioligand Assay , Receptor, Adenosine A2A , Receptors, Purinergic P1/metabolism , Reference Values , Systole , Treatment Outcome , Triazines/pharmacokinetics , Triazoles/pharmacokinetics
15.
Okajimas Folia Anat Jpn ; 79(2-3): 83-92, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12425382

ABSTRACT

Probucol is a lipid-lowering agent with an antioxidant effect; however, its influence on the liver remains unclear. The effects of probucol on hyperlipidemic rabbit liver are investigated to add a structural data on its therapeutical profile. Local albino rabbits were divided into three groups. 1) Hyperlipidemic group: fed with 1% cholesterol (150 g/kg/day) enriched chow for 2 months. 2) Probucol treated group: group 1 + intraperitoneal probucol (10 mg/kg/day) administration for 15 days. 3) Control group fed with normal chow. The blood lipid profile was investigated biochemically. Liver samples were examined electronmicroscopically. Within the parenchymal cells of group 1, the amount of rough surfaced endoplasmic reticulum was increased, its cisterna was dilated displaying a moderately electron dense substance in it and showed close apposition with the condensed mitochondria. In group 2, smooth surfaced endoplasmic reticulum was in extensive amounts filling almost all of the cytoplasm, displayed a reticular, degenerated appearance and was in close relation with the condensed, degenerated mitochondria. Probucol may cause degenerative changes on the liver parenchyme at the subcellular level. It alters the structure of these cells mainly acting on the smooth surfaced endoplasmic reticulum and the mitochondria that are known to be involved in cellular detoxification.


Subject(s)
Anticholesteremic Agents/pharmacology , Hyperlipidemias/drug therapy , Hyperlipidemias/pathology , Liver/pathology , Probucol/pharmacology , Animals , Endoplasmic Reticulum/ultrastructure , Female , Liver/ultrastructure , Male , Microscopy, Electron , Rabbits , Vacuoles/ultrastructure
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