Orally given gastroprotective capsaicin does not modify aspirin-induced platelet aggregation in healthy male volunteers (human phase I examination).

Capsaicin is a well-known component of red pepper. Recent studies have shown that capsaicin could prevent gastric ulcer provoked by various NSAID-s like acetylsalicylic acid (ASA). Primary objective of this human clinical phase I trial was to investigate whether two different doses of capsaicin co-administered with ASA could alter the inhibitory effect of ASA on platelet aggregation. 15 healthy male subjects were involved in the study and treated orally with 400 µg capsaicin, 800 µg capsaicin, 500 mg ASA, 400 µg capsaicin+500 mg ASA and 800 µg capsaicin+500 mg ASA. Blood was drawn before and 1, 2, 6 and 24 hours after the drug administration. After that epinephrine induced platelet aggregation was measured by optical aggregometry. Between treatments, volunteers had a 6-day wash-out period. Our results showed that capsaicin had no effect on platelet aggregation, while as expected, ASA monotherapy resulted in a significant and clinically effective platelet aggregation inhibition (p ≤ 0.001). The combined ASA-capsaicin therapies reached equivalent effectiveness in platelet aggregation inhibition as ASA monotherapy. Our investigation proved that capsaicin did not influence the inhibitory effect of ASA on platelet aggregation, thus the capsaicin-ASA treatment would combine the antiplatelet effect of ASA with the possible gastroprotection of capsaicin.

The role of hemorheological factors in cardiovascular medicine.

Cardiovascular diseases (CVD) are the most frequent cause of death throughout the world. The coronary vessel system is a special part of the circulation since there is a continuous change in blood flow, perfusion pressure and shear rate during each cardiac cycle. It is also the place of the narrowest capillaries in the human body, therefore the role of rheological alterations may be of greater importance than in the other parts of the circulatory system. During the past decades, our group has investigated hemorheological parameters (HP) in over 1,000 patients diagnosed with various forms of ischemic heart disease (IHD). In one prospective study, we measured the HP of patients with acute coronary syndrome (ACS). On admission, all examined variables were significantly worse than those of control subjects. During the hospital phase, some of the HP showed further deterioration, and HP remained in the pathologic range during the follow-up period. In another study, we showed that HP are in close correlation with the severity of coronary artery disease. In patients treated with percutaneous coronary intervention, changes in HP were very similar to those observed in subjects with ACS. In a recent study, we analyzed HP in patients undergoing CABG surgery. Our data suggest a hemorheological advantage of off-pump surgery. In another study low Hct/WBV ratio can be regarded as a risk factor of cardiac death in IHD. Our data indicate that rheological parameters are significantly altered in patients with IHD: the extent of the alterations is in excellent correlation with the clinical severity of the disease. Our findings prove that HP play a critical role in the pathogenesis of myocardial ischemia. In recent in vitro and in vivo studies we have investigated the effects of red wine on hemorheological parameters. Our results show that moderate red wine consumption has beneficial effects on hemorheological parameters which may contribute to the French paradox.

Antiplatelet effect of acetylsalicylic acid, metamizole and their combination - in vitro and in vivo comparisons.

BACKGROUND: Acetylsalicylic acid (ASA) plays an important role in the treatment and prevention of cardiovascular diseases. Metamizole (MET) is an analgesic and antipyretic medicine, it is not used as an antiplatelet drug. OBJECTIVES: We aimed to examine the antiplatelet effect of MET and the possible interactions between the drugs. METHODS: In our in vitro investigations different concentrations of ASA and MET solutions were added to blood. To examine the interactions MET and ASA were added together. In our in vivo crossover study intravenous MET, oral ASA or both drugs together were administered. Epinephrine and adenosine-diphosphate induced platelet aggregation was determined by optical aggregometry. RESULTS: Epinephrine-induced aggregation was completely inhibited in all ASA and MET concentrations in vitro. Lower, ineffective concentration of MET prevented the antiplatelet effect of ASA. The inhibition was completely restored when higher concentration of ASA was used or when ASA was added first. Our in vivo study showed that in the MET group rapid onset of inhibition was developed and there was no inhibition after one day. In the ASA group platelet aggregation decreased slowly but still had significant inhibitory effect after 72 hours. Combined therapy showed similar changes to the MET group. CONCLUSION: Antiplatelet effect of MET and ASA did not differ significantly in vitro. The observations may indicate a competitive interaction between the two drugs. The in vivo experiments showed that intravenously administered MET is an effective antiplatelet drug and can be considered as a therapeutic alternative, when ASA cannot be used in oral form.

Moderate red wine consumption improves hemorheological parameters in healthy volunteers.

Pieces of epidemiological evidence have supported that moderate red wine consumption reduces the risk of cardiovascular diseases (French-paradox). Our previous in vitro experiment has demonstrated favourable hemorheological effects of red wine, alcohol-free red wine extract and ethanol. Thirty-nine healthy, non-smoking male volunteers between 18-40 years were assigned into two groups: control group had drunk water, while red wine group had consumed 2 dl of red wine each day at dinner for 3 weeks. No alcohol had been drunk for one week prior to the study. Blood was obtained in the morning of the first and last day. Hematocrit (Hct), plasma (PV) and whole blood viscosity (WBV) (Hevimet 40 capillary viscometer), red blood cell (RBC) aggregation (Myrenne and LORCA aggregometer) and deformability (LORCA ektacytometer) were measured and Hct/WBV ratio was calculated to determine oxygen carrying capacity. Hct was adjusted to 40%. Hct and PV were not affected. WBV remained unchanged in controls, but it considerably decreased in the red wine group compared to the 3-week control group, while Hct/WBV ratio became significantly higher in the red wine group compared to the control (p < 0.05). RBC aggregation significantly decreased in the red wine group and became significantly lower compared to the 3-week controls (p < 0.05). Red wine significantly increased RBC deformability (p < 0.05) at high shear stress. Our results show that moderate red wine consumption has beneficial effects on hemorheological parameters which may contribute to the French-paradox.

Clindamycin release determined by high performance liquid chromatography from a novel low-cost local drug delivery system: a new potential treatment option for chronic osteomyelitis.

Osteomyelitis continues to be a severe problem worldwide, causing plenty of hospital admissions and entailing vast expenses. Previously, we developed a low-cost polymethyl-methacrylate (PMMA)-sorbitol based capsule system for local long-term drug delivery. In the present study we aimed to test the in vitro release of clindamycin capsules by high performance liquid chromatography. By the end of the clinically relevant period (42 days), the capsules released 70-100% of their load. Furthermore, the release kinetics suggested that an effective antimicrobial concentration may be maintained within the target area. Our findings indicate that these newly developed capsules may be a versatile device for local clindamycin delivery by providing efficient release and reducing financial burdens.

The influence of on-pump and off-pump coronary artery bypass grafting on hemorheological parameters.

Conditions during coronary artery bypass grafting (CABG) performed on beating heart (off-pump) are more physiological than using extracorporeal perfusion (on-pump). The present study aims to examine the hemorheological aspects of the two techniques. Blood samples were taken from patients undergoing on-pump (n = 25) and off-pump (n = 22) CABG, upon arrival to the operating theatre, after 20 and 40 minutes during the operation, after closing the thorax, on the 1st and 2nd postoperative days, and during the 2nd and 6th month control check-ups. Hematocrit (Hct), plasma and whole blood viscosity (PV, WBV; Hevimet 40 capillary viscometer), red blood cell (RBC) aggregation (Myrenne RBC aggregometer, LORCA) and deformability (LORCA, Carat FT-1 filtrometer), and platelet aggregation (Carat TX4 aggregometer) were determined. The morphology of red blood cells was investigated by scanning electron microscopy (SEM). Hct, PV, WBV and RBC aggregation decreased significantly during the early phase of the surgery, they started to recover during the postoperative period, and reached the baseline values by the 2nd and 6th month control check-ups. These parameters were significantly lower in samples taken after 20 and 40 minutes in the on-pump group. SEM showed rather damaged and malformed cells in case of on-pump surgery. Ektacytometry showed no significant difference, but RBC deformability was impaired during on-pump surgery when measured by filtrometry. The decrease in platelet aggregation was more pronounced by the end of surgery in case of on-pump technique. During CABG rheological parameters change less when using the off-pump method, and mechanical damage of RBCs are also smaller. The off-pump technique seems to be favorable from a hemorhelogical point of view.

In vitro hemorheological effects of red wine and alcohol-free red wine extract.

The French paradox is based on epidemiological evidence which supports that moderate red wine consumption reduces the risk of cardiovascular diseases. A number of experimental animal studies reported favourable cardiovascular effects of alcohol-free red wine extract (AFRW). Our study was designed to determine red wine and AFRW induced changes in various hemorheological parameters. These effects may play a role in the pathophysiology of the French paradox regarding the cardiovascular protective impacts of red wine. Blood samples of healthy volunteers were mixed with red wine to achieve alcohol concentrations of 1 per thousand, 3 per thousand and 10 per thousand, respectively, with equivalent amount of AFRW or physiological saline. Blood samples were pretreated with red wine or AFRW in order to prove the protective effects on erythrocytes from impairment of deformability caused by the free radical generator phenazine methosulfate (PMS). Erythrocyte aggregation (Myrenne and LORCA), deformability (LORCA) and platelet aggregation (Carat TX4) were measured. Erythrocyte aggregation using Myrenne aggregometer was inhibited by red wine and AFRW compared to the saline treated samples. The difference reached already significance at 1 per thousand concentration at the AFRW samples (p < 0.05). Furthermore, red wine caused stronger inhibition than AFRW. The difference between the two agents became significant at 10 per thousand concentration (p < 0.05). LORCA aggregation index and threshold shear rate supported these results at the highest concentration. Erythrocyte deformability of healthy volunteers did not change significantly for any concentrations of red wine and AFRW. On the other hand AFRW at 3 per thousand concentration significantly prevented erythrocytes from impairment of deformability caused by PMS (p < 0.05). Platelet aggregation was significantly inhibited by the highest concentration of AFRW (p < 0.05). Our results show that red wine and AFRW have some beneficial effects on hemorheological parameters that may contribute to the French paradox.

The effect of aspirin on hemorheological parameters of patients with diabetic retinopathy.

Hemorheological factors play an important role in the pathogenesis of severe complications of diabetes. The diabetic retinopathy is the leading cause of blindness in patients aged 20-65 years. In our study we investigated the effect of aspirin on the hemorheological parameters in patients with different diabetic retinopathies. Hemorheological parameters (hematocrit, fibrinogen, plasma and whole blood viscosity, red blood cell aggregation) of diabetic patients with non-proliferative (n=14, mean age: 66 years) and proliferative retinopathy (n=8, mean age: 48 years) were measured. The results between the two groups were compared: twelve patients were taking aspirin (group A), while ten patients were not (group B).Hematocrit, fibrinogen, plasma and whole blood viscosity were significantly higher (p < 0.05-0.001) in patients with diabetic retinopathy who did not take aspirin than in those who took. No significant difference was observed in red blood cell aggregation parameters between the two groups. We could not find any significant difference in the measured parameters between patients with non-proliferative and proliferative diabetic retinopathy. According to our results, all the measured hemorheological parameters were in the pathological range, although aspirin treatment could decrease these factors and thus may help to prevent the progression of severe diabetic retinopathy and perhaps blindness.

Low hematocrit per blood viscosity ratio as a mortality risk factor in coronary heart disease.

Increased blood viscosity has not been associated with mortality risk in coronary heart disease (CHD). We aimed to investigate the predictive power of hematocrit per blood viscosity (Hct/BV) ratio as a marker of rheological oxygen carrying capacity of the blood to assess mortality risk of CHD. Elective coronary angiography was performed and CHD was proved in 109 patients in 1996 and 1997. In 78 cases (72%) complete follow up information was obtained in February 2006. During the follow up time (mean 8.9 years) 10 patients died due to cardiac cause (group C). Two patients died due to non-cardiac cause and 66 were still alive at the end of the follow up period (group NC, n=68). Mean hematocrit per blood viscosity (Hct/BV) ratio was significantly lower in group C comparing to NC (87+/-5; 93+/-9 Pa(-1)s(-1), SD, respectively, p=0.022). Other factors (body mass index, serum cholesterol, fibrinogen, hematocrit, plasma and blood viscosity, cardiac index, left ventricular ejection fraction) provided no statistical differences. Kaplan-Meier survival analysis showed only the impact of fibrinogen and Hct/BV ratio on cardiac mortality (p=0.029 and 0.009, respectively). Receiver operating characteristic curves proved only Hct/BV ratio to be able to differentiate between groups (area under curve: 0.716, p=0.028). Hct/BV ratio showed significant negative correlation with the frequency of hospital admissions (r=-0.377, p=0.03). Low Hct/BV ratio can be regarded as a risk factor of cardiac death in CHD.

Gender differences in hemorheological parameters of coronary artery disease patients.

Plasma fibrinogen concentration, plasma and whole blood viscosity (WBV) are independent risk factors of coronary artery disease (CAD). Fibrinogen seems to be a relatively stronger risk factor for women than for men, but men are more endangered by higher hematocrit (Hct) and WBV than women are. We have previously reported that a theoretically optimal Hct value can be determined using Hct/WBV ratio in healthy subjects, hyperlipidemic and Raynaud's disease patients. Our aim was to examine whether Hct/WBV ratio is differently correlated with Hct in men and women with proven CAD. In a retrospective study we analysed the hemorheological data of 162 CAD outpatients (107 men and 55 women). Coronary angiography, echocardiography and impedance cardiography were performed. Hemorheological parameters (Hct, fibrinogen level, plasma viscosity, WBV), blood picture, serum lipid concentrations were determined and Hct/WBV ratio was calculated. Mean ages of male and female patients were similar (54.9 and 55.4 years, respectively), but men had significantly higher coronary angiography score than women. Mean left ventricular ejection fraction, stroke volume index and cardiac index showed no significant differences in men and women. Similarly, lipid concentrations, fibrinogen levels and plasma viscosities demonstrated no statistical differences. However, Hct, WBV and Hct/WBV ratios were significantly higher in male than in female patients (p < 0.00001; p < 0.00001 and p < 0.005, respectively). The most striking gender difference was found in the correlation between Hct/WBV ratio and cardiac index. Men older than 56 years showed negative, women positive correlation (r = -0.485, p = 0.01; r = 0.468, p = 0.006, respectively). This study demonstrates that Hct/WBV ratio as a rheological oxygen carrying capacity parameter is positively correlated with the cardiac index as it can be expected. However, the correlation is negative in elder men indicating an unhealthy relation between hemodynamic and hemorheologic parameters.

Erythrocyte transport efficacy of human blood: a rheological point of view.

BACKGROUND: Large-scale epidemiological studies have demonstrated that both anaemia and polycytaemia are independent cardiovascular risk factors. This was substantiated by the Framingham study, which demonstrated a U-shaped relation between haemoglobin concentration and mortality. It was previously noted that delineating the corresponding haematocrit/blood viscosity ratios in the function of haematocrit provided a distribution of an inverted U-shaped curve. The peak appeared physiologically important because it denotes a healthy balance between a relatively high oxygen binding capacity and a moderately low blood viscosity. It was the aim of this study to examine the mathematical relationship between the haematocrit and haematocrit/blood viscosity ratio. MATERIALS AND METHODS: In a retrospective study, the haemorheological data of 32 healthy controls, 52 outpatients with hyperlipidaemia and 120 outpatients with Raynaud's disease were analyzed. Whole blood viscosity was measured with Hevimet 40 capillary viscometer at 37.0 degrees C and at shear rates of 10 s(-1), 90 s(-1) and 200 s(-1). RESULTS: Haematocrit/blood viscosity ratios in the function of haematocrit values showed a Gaussian association in the healthy subjects, hyperlipidaemic and Raynaud's disease outpatient groups. Peak values (i.e. the rheologically optimal haematocrit) were shear-rate and group dependent and were found at 44.3%, 43.5% and 38.3% in controls, hyperlipidaemic and Raynaud's disease patients, respectively, at a shear rate of 90 s(-1). CONCLUSIONS: This is one of the first reports in which a theoretically optimal haematocrit value was determined using the haematocrit/blood viscosity ratio. Further studies are needed to examine the potential clinical usefulness of this approach.

Hemorheological disturbances in patients with chronic cerebrovascular diseases.

Hemorheological disturbances may occur in more than 40% of patients with ischemic cerebrovascular diseases. In this study the changes of rheological factors--hematocrit, plasma fibrinogen concentration, whole blood and plasma viscosity, red blood cell aggregation and deformability were investigated in 297 patients (173 males, 124 females, mean age 60 +/- 11 years) with transient ischemic attack or chronic phase (> 3 months after onset) ischemic stroke, and in 73 healthy volunteers (35 males, 38 females, mean age 38 +/- 7 years). Hematocrit, plasma and whole blood viscosity were significantly (p < 0.0001) elevated in cerebrovascular patients compared to controls. Plasma fibrinogen concentration (p < 0.001), red blood cell aggregation (p < 0.05) and deformability (p < 0.01) were also impaired in stroke patients. Hemorheological disturbances were dominant in stroke patients with diabetes, hyperlipidemia and smoking habits. Hematocrit, plasma viscosity and red blood cell aggregation showed a significant (p < 0.025-0.001) correlation with the severity of carotid artery stenosis. We could not find any characteristic distribution of rheological parameters among the three subtypes of brain ischemia. Our results show that all of the measured rheological parameters are significantly impaired in chronic ischemic cerebrovascular disorders, especially in diabetic, smoking and alcoholic patients. They correlate with the severity of the carotid artery stenosis, but there is no association with the type of ischemic stroke.

Follow-up of hemorheological parameters and platelet aggregation in patients with acute coronary syndromes.

Pathologic hemorheological parameters and increased platelet aggregation in association with other risk factors significantly increase the possibility of the development of myocardial ischemia. Hemorheological parameters and platelet aggregation were investigated in 157 patients (mean age: 65+/-12 years) with acute coronary syndromes and in 68 healthy subjects (mean age: 36+/-6 years). Plasma fibrinogen, plasma and whole blood viscosity, red blood cell aggregation and filterability and platelet aggregation were measured in the hospital phase (after admission, on 2nd and 6th days) and monitored after discharge (at 1, 6 and 12 months). After admission all these parameters were significantly higher in patients than in control subjects (p<0.01) and almost all of them remained in the pathologic range at discharge. Some of the rheologic parameters showed a slight improvement after 1 month, but hematocrit and whole blood viscosity were higher than those after admission and of control subjects (p<0.05). After 6 and 12 months these parameters showed a small, but significant increase. Pathologically altered hemorheological parameters could be observed in patients with classical cardiovascular risk factors and significant improvement was found after elimination of them. Antiplatelet therapy was efficient in about half of the treated patients after admission; and despite a significant improvement, the proportion of ineffectively treated patients was still considerable during the follow-up. Our results support the role of abnormal hemorheological parameters in the development of myocardial ischemia and draw attention to the rheologic risk of these patients. The results of platelet aggregation measurements show the insufficiency of antiplatelet therapy at some cases and confirm the importance of guided secondary prevention.

QRS Score: a composite index of exercise-induced changes in the Q, R, and S waves during exercise stress testing in patients with ischemic heart disease.

BACKGROUND: To detect ischemic heart disease, the exercise-induced ST-segment displacement is the most frequently used ECG parameter. However, the value of this marker was proven to be limited with varying sensitivity and specificity. A new parameter, called QRS score, emerged to improve the efficacy of exercise testing. METHODS: Our study aimed at evaluating the diagnostic value of QRS score in ischemic heart disease, investigating males and females separately, and examining the effects of heart rate and antiischemic medication. QRS score and cumulative ST depression were calculated in 212 patients and correlated to the findings of the stress myocardial perfusion SPECT (197 subjects) or coronary angiography (54 subjects). RESULTS: An inverse correlation could be found between the QRS score and the results of myocardial SPECT and coronary angiography in the whole population, especially in males; females did not show a significant relationship. In patients with conclusive tests (achieving 85% of the maximal predicted heart rate) QRS score correlated significantly with the results of the stress myocardial perfusion SPECT and coronary angiography. The sensitivity, specificity, and validity of the QRS score surpassed those of the cumulative ST depression in the entire population as well as in patients with conclusive tests. The antiischemic medication did not affect correlation values. CONCLUSION: QRS score was significantly related to the extent of myocardial ischemia and the severity of coronary heart disease, thus along with the analysis of ST-segment displacement may contribute to the more precise evaluation of exercise testing.

Effects of doxazosin on hemorheological, hemodynamic and lipid parameters in patients with essential hypertension.

It is known from previous studies that hemorheological parameters are altered in patients with essential hypertension. The hemorheological and hemodynamical effects of doxazosin, a selective alpha-1-adrenoreceptor blocker agent, was examined in twenty patients (mean age: 54+/-10 years) with essential hypertension. Hemorheologic (hematocrit, fibrinogen, plasma and whole blood viscosity) and hemodynamic (cardiac output and index, total peripheral resistance) parameters and plasma lipids were determined. The measurements were carried out before the beginning of the treatment, after 1 week and after 12 weeks treatment periods. Besides significant reduction of blood pressure and total peripheral resistance (p < 0.001), a decrease in cholesterol (p < 0.001) and triglyceride (p < 0.01) levels and a beneficial effect on hemorheological parameters was detected. Fibrinogen and plasma viscosity decreased significantly (p < 0.01). Hematocrit value was also lower after one week (p < 0.001), then an increase could be seen. Whole blood viscosity showed similar changes as hematocrit, but the degree of its final increase was slighter, which was supported by the significantly lower value of corrected blood viscosity (p < 0.05).

Hemorheological and hemodynamic parameters in patients with essential hypertension and their modification by alpha-1 inhibitor drug treatment.

Hemorheological factors play an important role in the pathogenesis of different cardiovascular diseases. The hemorheological and hemodynamic parameters in essential hypertension and their possible modification by antihypertensive treatment were examined in the following two studies. In the first study the fundus appearance and hemorheological parameters (plasma and whole blood viscosity (WBV), fibrinogen level) of 33 hypertensive patients (mean age: 55 years) were examined. The fundus appearance showed retinopathy in all the cases between stages I-III. All the measured hemorheological parameters of the examined patients were in the pathological range (WBV at 90 s(-1): 5.18 mPa s) and were significantly (p < 0.01) higher than in healthy controls (WBV at 90 s(-1): 4.18 mPa s). The hemorheological factors showed a parallel deterioration with the fundus appearance, namely their values were significantly (p < 0.01) higher in patients with a fundus appearance stage III (WBV at 90 s(-1): 6.02 mPa s) than stage I (WBV at 90 s(-1): 4.51 mPa s). These results show that there is a correlation between hemorheological parameters and fundus appearance in hypertensives, and this suggests that hemorheological factors may play a role in the development of hypertensive retinopathy. In the second study the hemorheological and hemodynamical effects of Doxazosin, a selective alpha-1-adrenoreceptor blocker agent, was examined in twenty patients (mean age: 54 years) with essential hypertension. Hemorheologic (hematocrit, fibrinogen, plasma and whole blood viscosity) and hemodynamic (cardiac output and index, total peripheral resistance) parameters and plasma lipids were determined. The measurements were carried out before the beginning of the treatment, after 1 week and after 12 weeks treatment periods. Besides significant reduction of blood pressure and total peripheral resistance (p < 0.001), a decrease in cholesterol (p < 0.001) and triglycerides (p < 0.01) levels and a beneficial effect on hemorheological parameters was detected. Fibrinogen and plasma viscosity decreased significantly (p < 0.01). Hematocrit value was also lower after one week (p < 0.001), then an increase could be seen. Whole blood viscosity showed similar changes as hematocrit, but the degree of its final increase was slighter, which was supported by the significantly lower value of corrected blood viscosity (p < 0.05). All these findings indicate that hemorheological factors may play a role in the pathogenesis and in the development of organ damages in hypertension.

Small doses of capsaicin given intragastrically inhibit gastric basal acid secretion in healthy human subjects.

Although the direct inhibitory effect of small dose of capsaicin on gastric secretory responses was proved in animal observations, the role of capsaicin-sensitive afferent nerves (CSAN) and the effect of capsaicin applied in small and high doses on gastric secretion in human has not been clarified yet. In this study we investigated the influence of different small doses (100-800 microg) of capsaicin given intragastrically through an orogastric tube on gastric basal secretory responses in 10 healthy human subjects. Gastric basal secretory responses (volume, H+-concentration, H+-output) were measured from the suctions of gastric juice for a 1-h period. It has been found that: a) capsaicin dose-dependently inhibited the volume and H+-output of gastric juice; b) ID50 was found to be about 400 microg for capsaicin on gastric acid secretion; c) the time interval for capsaicin-induced gastric inhibition existed for about 1 h indifferently from the higher dose (800 microg) of capsaicin given after. It has been concluded that the capsaicin (given in small doses) inhibits the gastric basal acid output via stimulation of the inhibition of capsaicin sensitive afferent nerves.

Capsaicin increases gastric emptying rate in healthy human subjects measured by 13C-labeled octanoic acid breath test.

The role of capsaicin-sensitive primary afferent sensory nerves in the regulation of gastrointestinal motility in human is not clarified yet. In this study, we investigated the effect of 400 microg capsaicin given intragastrically on gastric emptying measured by 13C-octanoic acid breath test in ten healthy human subjects. Four parameters of gastric emptying curves were taken into consideration: 1) maximum value of the curve, 2) time belonging to this maximum, 3) slope of the rising part of the curve and 4) time belonging to the 50% of the area under the curve. Administration of 400 microg capsaicin significantly increased the slope of gastric emptying curve (from 0.1 +/- 0.01 to 0.139 +/- 0.014 U x min(-1), P < 0.05) and significantly decreased the time belonging to the maximum value of emptying curve (from 150 +/- 18 to 75 +/- 12 min, P < 0.05) and the time belonging to the 50% of the area under the curve (from 112 +/- 15 to 99 +/- 14 min, P < 0.05). According to our results 400 microg capsaicin enhances gastric emptying rate in healthy human subjects.

Hemorheological parameters in coronary artery disease.

Hemorheological parameters are primary risk factors in ischemic heart disease (IHD). In the present study the relation of these parameters to the severity of coronary artery disease (CAD) was examined. The data of 109 patients (mean age: 55+/-9 years) undergoing coronary angiography and 59 healthy controls (mean age:35+/-10 years) were analyzed. Hemorheological parameters (hematocrit, fibrinogen level, plasma viscosity (PV) and apparent whole blood viscosity (WBV)) were determined and the circulatory index (CRI) was calculated. Patients were classified into three groups according to their coronary vessel state based on the coronary angiogram: Group 1 (n = 19, mean age: 53+/-8 years) without significant CAD, Group 2 (n = 19, mean age: 51+/-11 years) with single vessel disease, Group 3 (n = 71, mean age: 57+/-8 years) with multivessel disease. All the measured hemorheological parameters of IHD patients were significantly higher than those of controls. Fibrinogen and PV were significantly elevated in Groups 2 and 3 compared with Group 1 (p < 0.05 and 0.01). Hematocrit and WBV were significantly increased in Group 3 compared with Groups 1 and 2 (p < 0.05). CRI was significantly decreased in IHD patients, and it was also lower in Group 3 than in Group 2 (p < 0.05). These results indicate that hemorheological parameters may play a role in the pathogenesis and development of CAD.