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1.
Journal of Southern Medical University ; (12): 411-417, 2022.
Article in Chinese | WPRIM | ID: wpr-936331

ABSTRACT

OBJECTIVE@#To investigate the effect of pirfenidone for reducing urethral stricture following urethral injury in rats and explore the possible mechanism.@*METHODS@#Thirty male SD rats were randomly assigned into negative control group, positive control group and pirfenidone group (n=10). In pirfenidone and positive control groups, the rats were subjected to incision of the posterior urethral cavernous body followed by daily intraperitoneal injection of pirfenidone (100 mg/kg) and an equivalent volume of solvent, respectively. The rats in the negative control group were given intraperitoneal injections of solvent without urethral injury. At two weeks after modeling, retrograde urethrography was performed for observing urethral stricture, and the injured urethral tissues were harvested for HE staining, Masson staining, immunohistochemical staining and Western blotting for detecting the protein expressions of α-SMA and TGF-β1. The mRNA expressions of the inflammatory factors TNF-α, IL-6, and IL-1β were detected using qRT-PCR.@*RESULTS@#The body weight of the rats in pirfenidone group was significantly decreased compared with that in the other two groups (P < 0.05). Retrograde urethrography showed significant narrowing of the urethra in the positive control group but not in the pirfenidone group. HE staining of the injured urethral tissues showed obvious proliferation of urethral epithelial cells with narrow urethral cavity and increased inflammatory cells in positive control group. The pathological findings of the urethra were similar between pirfenidone group and the negative control group. Masson staining revealed obviously reduced collagen fibers and regular arrangement of the fibers in pirfenidone group as compared to the positive control group. Compared with those in the negative control group, the expressions of α-SMA and TGF-β1 were significantly increased in the positive control group, and pirfenidone treatment significantly inhibited their expressions (P < 0.05 or 0.01). Pirfenidone also significantly inhibited the mRNA expressions of TNF-α, IL-6, and IL-1β in the injured urethral tissue (P < 0.05 or 0.01).@*CONCLUSION@#Pirfenidone can prevent urethral fibrosis and stricture after urethral injury possibly by inhibiting the TGF-β1 pathway and inflammatory response.


Subject(s)
Animals , Female , Humans , Male , Rats , Interleukin-6/metabolism , Pyridones/pharmacology , RNA, Messenger/metabolism , Rats, Sprague-Dawley , Solvents , Transforming Growth Factor beta1/metabolism , Tumor Necrosis Factor-alpha/metabolism , Urethral Stricture/pathology
2.
Braz. j. biol ; 79(3): 383-394, July-Sept. 2019. tab, graf
Article in English | LILACS | ID: biblio-1001447

ABSTRACT

Abstract Bidens pilosa L. is a heterocarpic weed species with two cypselae types that present morpho-physiological differences, being the peripheral type smaller and slower to germinate than the central one. We aimed to verify how the germination mechanism varied between types. We focused on two mechanisms: (1) pericarp constraints (physical and chemical) and (2) hormonal stimulation (Abcisic acid [ABA] and Gibberellin [GA]). Both cypselae types are physically constrained by the pericarp, for when it is excised both seed types increase their germination, but behavioral differences still remain. The pericarp of the peripheral type also has chemical inhibitors that effectively inhibited germination of the intact central cypsela. To test the hormonal effects, we focused on the ABA:GA control. Both cypselae responded to an exogenous ABA concentration gradient, however there is no variation between types on the sensitivity to it. Also, both cypselae types were indifferent to Fluridone (ABA inhibitor), which indicates that the dormancy is not maintained by de novo ABA synthesis. Cypselae types had different sensitivity to an exogenous GA3 gradient, the central type being more sensitive to the treatment than the peripheral one. But when the endogenous GA synthesis was blocked by Paclobutrazol, both types responded equally to same GA3 concentrations. This indicates that endogenous GA synthesis may be related to differences observed on germination of cypselae types. To conclude, seed types differ on their growth potential to overcome the pericarp resistance: while the inhibitor in the peripheral pericarp reduces growth potential, GA increases it.


Resumo Bidens pilosa L. é uma espécie de planta daninha heterocarpica com dois tipos de cipselas que possuem diferenças morfofisiológicas, sendo o tipo periférico de menor tamanho e com germinação lenta se comparado com o central. Nosso objetivo foi verificar como o mecanismo de germinação varia entre os tipos. Focamos em dois mecanismos: (1) restrição causada pelo pericarpo (física e química) e (2) estímulo hormonal (Ácido abscísico [ABA] e Giberelina [GA]). Os tipos de cipselas são fisicamente limitados pelo pericarpo, pois quando ambos os tipos de sementes são excisados há um aumento na germinação, contudo as diferenças no processo se mantém. O pericarpo do tipo periférico ainda possui inibidores que efetivamente retardam a germinação das cipselas centrais intactas. Para testar os efeitos hormonais, nós focamos no controle pelo ABA:GA. Ambas cipselas responderam ao gradiente de concentração de ABA exógeno, contudo não houve variação na sensibilidade entre os tipos. Ainda, ambos tipos de cipselas foram indiferentes à Fluoridona (inibidor de ABA), que indica que a dormência não é mantida pela nova síntese de ABA. Tipos de cipselas apresentam diferentes sensibilidades ao gradiente exógeno de GA3, com o tipo central sendo mais sensível ao tratamento que o periférico. Mas quando a síntese endógena de GA foi bloqueada pelo Paclobutrazol, ambos os tipos responderam de forma similar às concentrações de GA 3. Isso indica que a síntese de GA endógena pode estar relacionada com a diferença observada na germinação dos dois tipos de cipselas. Para concluir, os tipos de sementes diferem no potencial para superar a resistência do pericarpo, sendo o inibidor no pericarpo da cipsela periférica o redutor do potencial de crescimento, enquanto a GA aumenta esse potencial.


Subject(s)
Plant Growth Regulators/pharmacology , Pyridones/pharmacology , Abscisic Acid/pharmacology , Germination/physiology , Bidens/physiology , Herbicides/pharmacology , Seeds/growth & development , Seeds/drug effects , Germination/drug effects , Bidens/drug effects
3.
Braz. j. med. biol. res ; 52(11): e8772, 2019. graf
Article in English | LILACS | ID: biblio-1039259

ABSTRACT

This study aimed to investigate the mechanism of fluorofenidone (AKF-PD) in treating renal interstitial fibrosis in rats with unilateral urinary obstruction (UUO). Thirty-two male Sprague-Dawley rats were randomly divided into sham, UUO, UUO + enalapril, and UUO + AKF-PD groups. All rats, except sham, underwent left urethral obstruction surgery to establish the animal model. Rats were sacrificed 14 days after surgery, and serum was collected for renal function examination. Kidneys were collected to observe pathological changes. Immunohistochemistry was performed to assess collagen I (Col I) protein expression, and terminal deoxynucleotidyl transferase-mediated nick end-labeling staining to observe the apoptosis of renal tubular epithelial cells. The expression of Fas-associated death domain (FADD), apoptotic protease activating factor-1 (Apaf-1), and C/EBP homologous protein (CHOP) proteins was evaluated by immunohistochemistry and western blot analysis. AKF-PD showed no significant effect on renal function in UUO rats. The pathological changes were alleviated significantly after enalapril or AKF-PD treatment, but with no significant differences between the two groups. Col I protein was overexpressed in the UUO group, which was inhibited by both enalapril and AKF-PD. The number of apoptotic renal tubular epithelial cells was much higher in the UUO group, and AKF-PD significantly inhibited epithelial cells apoptosis. The expression of FADD, Apaf-1, and CHOP proteins was significantly upregulated in the UUO group and downregulated by enalapril and AKF-PD. In conclusion, AKF-PD improved renal interstitial fibrosis by inhibiting apoptosis of renal tubular epithelial cells in rats with UUO.


Subject(s)
Animals , Male , Pyridones/pharmacology , Ureteral Obstruction/pathology , Apoptosis/drug effects , Epithelial Cells/drug effects , Kidney Diseases/pathology , Pyridones/metabolism , Blood Urea Nitrogen , Fibrosis , Angiotensin-Converting Enzyme Inhibitors/metabolism , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Enalapril/metabolism , Enalapril/pharmacology , Random Allocation , Rats, Sprague-Dawley , Creatinine/blood , Collagen Type I/drug effects , Collagen Type I/metabolism , Disease Models, Animal , Transcription Factor CHOP/drug effects , Apoptotic Protease-Activating Factor 1/drug effects , Apoptotic Protease-Activating Factor 1/metabolism , Fas-Associated Death Domain Protein/drug effects , Fas-Associated Death Domain Protein/metabolism
4.
Rev. méd. Chile ; 142(12): 1553-1564, dic. 2014. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-734862

ABSTRACT

Background: Liver fibrogenic processes are related to cellular redox state. Glutathione (GSH) is the major cellular antioxidant. GSH induced activation could be related to antifibrogenic effects. Aim: To explore the association between the antifibrogenic effect and pro-antioxidant mechanisms of alpha-lipoic acid (ALA) and pirfenidone (PFD). Material and Methods: HepG2 cells and primary HSC cultures were exposed to menadione 0.1 μM (MEN) as oxidative stress inducer and treated to ALA (5 mM) or PFD (10 μM, 100 μM y 1000 μM). Results: In HSC, PFD decreased cell proliferation and the expression of COL1A1, TGF-β1, TIMP1, IL6, TNFα and MCP1 induced by MEN. Furthermore it was confirmed that ALA and PFD activate diverse antioxidants mediators, however MEN decreases this response. Then, MEN, ALA and PFD induce an antioxidant response, the first one as a response to injury and the latter two as pro-antioxidant inducers. Therefore, when cells are exposed to oxidative stress, endogenous systems activate a battery of mediators that increase the antioxidant potential. When these cells are treated with ALA and PFD, de novo formation of protective genes decreases since previous elicited protection induced in response to injury, enhance ALA and PFD effects. Conclusion: Regardless of the route of action, ALA and PFD induce the biosynthesis of antioxidants mediators which is associated with modulation of fibrogenic processes.


Subject(s)
Humans , Antioxidants/pharmacology , Hepatocytes/drug effects , Oxidative Stress/drug effects , Pyridones/pharmacology , Thioctic Acid/pharmacology , Cells, Cultured , Oxidation-Reduction/drug effects
5.
Article in English | IMSEAR | ID: sea-162168

ABSTRACT

Atrial Fibrillation (AF) is the most common arrhythmia. AF is a major risk factor for stoke. Warfarin has been available for more than 60 years and until recently it was the only oral anticoagulant used for the prevention of stroke. Despite the extensive studies and proven efficacy, its utility is limited by multiple factors. Warfarin interacts with a multitude of drugs and foods, has a delayed onset of action, has a narrow therapeutic range, requires routine lab monitoring and exhibits variable responses in patients. The novel agents dabigatran, rivaroxaban and apixaban have the potential to have some of the limitations of warfarin. This article will discuss the pharmacokinetic and pharmacological considerations and different characteristics of the novel anticoagulants when used for the prevention of AF.


Subject(s)
Aged , Aged, 80 and over , Anticoagulants/pharmacokinetics , Anticoagulants/pharmacology , Antithrombins/pharmacokinetics , Antithrombins/pharmacology , Atrial Fibrillation/drug therapy , Atrial Fibrillation/surgery , Atrial Fibrillation/therapy , Benzimidazoles/pharmacokinetics , Benzimidazoles/pharmacology , Factor Xa Inhibitors/pharmacokinetics , Factor Xa Inhibitors/pharmacology , Humans , Morpholines/pharmacokinetics , Morpholines/pharmacology , Pyrazoles/pharmacokinetics , Pyrazoles/pharmacology , Pyridones/pharmacokinetics , Pyridones/pharmacology , Thiophenes/pharmacokinetics , Thiophenes/pharmacology , Warfarin/pharmacokinetics , Warfarin/pharmacology , beta-Alanine/pharmacokinetics , beta-Alanine/pharmacology
6.
An. bras. dermatol ; 89(4): 581-586, Jul-Aug/2014. tab
Article in English | LILACS | ID: lil-715536

ABSTRACT

BACKGROUND: Onychomycosis or nail fungal infection is the most common nail disease. Despite the wide range of studies on this condition, it remains difficult to establish the correct diagnosis and effective treatment. OBJECTIVES: To evaluate the efficacy of classical laboratory methods for the diagnosis of onychomycosis, and the in vitro susceptibility of the its main etiological agent to antifungals used in routine. METHODS: Nail samples of 100 patients with clinically suspected feet onychomycosis were collected to confirm the diagnosis by direct mycological examination and fungal culture. In vitro antifungal susceptibility testing was performed against strains of the main dermatophyte isolated by microdilution, according to the standardized protocol (M38-A2 - CLSI) RESULTS: Clinical diagnosis of onychomycosis was confirmed by laboratory analysis in 59% of patients. Of these, 54.2% were positive only in direct mycological examination, 44.1% in direct mycological examination and culture, and one case (1.7%) was positive only in culture, resulting in weak agreement between these tests (Kappa = 0.385; p <0.001) High minimum inhibitory concentration values of fluconazole and itraconazole were observed in 66.7% and 25.0% of isolates of T. rubrum tested. Additionally, high MIC values of terbinafine and ciclopirox was detected in only one isolate, and this was one of the strains in which in vitro activity of itraconazole and fluconazole has not been proven. CONCLUSIONS: Poor agreement was observed between direct mycological examination and culture for the diagnosis of onychomycosis, with direct mycological examination being significantly more sensitive. Except for fluconazole, the other three antifungals tested showed good in vitro activity against clinical isolates of T. rubrum. .


Subject(s)
Adult , Female , Humans , Male , Middle Aged , Antifungal Agents/pharmacology , Onychomycosis/diagnosis , Onychomycosis/microbiology , Trichophyton/drug effects , Trichophyton/isolation & purification , Cross-Sectional Studies , Dose-Response Relationship, Drug , Fluconazole/pharmacology , Itraconazole/pharmacology , Microbial Sensitivity Tests , Naphthalenes/pharmacology , Onychomycosis/drug therapy , Prospective Studies , Pyridones/pharmacology , Reproducibility of Results
7.
Journal of Korean Medical Science ; : 289-295, 2009.
Article in English | WPRIM | ID: wpr-42857

ABSTRACT

The standard iron-chelator deferoxamine is known to prevent the growth of coagulase-negative staphylococci (CoNS) which are major pathogens in iron-overloaded patients. However, we found that deferoxamine rather promotes the growth of coagulase-positive Staphylococcus aureus. Accordingly, we tested whether deferiprone, a new clinically-available iron-chelator, can prevent the growth of S. aureus strains as well as CoNS. Deferiprone did not at least promote the growth of all S. aureus strains (n=26) and CoNS (n=27) at relatively low doses; moreover, it could significantly inhibit the growth of all staphylococci on non-transferrin-bound-iron and the growth of all CoNS on transferrin-bound iron at relatively high doses. At the same doses, it did not at least promote the growth of all S. aureus strains on transferrin-bound-iron. These findings indicate that deferiprone can be useful to prevent staphylococcal infections, as well as to improve iron overload, in iron-overloaded patients.


Subject(s)
Humans , Deferoxamine/pharmacology , Iron/metabolism , Iron Chelating Agents/pharmacology , Iron Overload/metabolism , Microbial Sensitivity Tests , Pyridones/pharmacology , Staphylococcus/drug effects , Staphylococcus aureus/drug effects , Transferrin/metabolism
8.
Journal of Korean Medical Science ; : 527-533, 2003.
Article in English | WPRIM | ID: wpr-156008

ABSTRACT

Pirfenidone(PFD) is a newly developed anti-fibrotic agent. We evaluated the effect of PFD for the prevention of renal fibrosis using a spontaneous progressive glomerulosclerosis animal model, FGS/Kist mice. Male and female FGS/Kist mice were fed a diet containing 0.5% PFD or the same control diet (CD) without PFD, for 1, 2, or 3-month periods. Body weight was monitored for the general effect of PFD on the mice. Proteinuria and glomerular filtration rate (GFR) were evaluated for renal function. The sclerosis index was examined for the morphological changes. There were no significant changes in body weight between the PFD and control groups in both sexes. Proteinuria levels were low in all the PFD groups compared to the corresponding CD groups. The sclerosis scores were also reduced in both sexes of the 3-month PFD groups (p<0.05), and glomerular filtration rates were increased in both sexes of the 3-month PFD groups compared to the CD groups. The treatment of PFD for 1 or 2-month periods did not have statistic significances but the treatment for 3 months had statistic significances in sclerosis and GFR compared to CD groups. These results suggested that long-term administration of PFD sup-pressed the progression of glomerulosclerosis and improved renal function of the renal function of the FGS/Kist mice.


Subject(s)
Animals , Female , Male , Mice , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Body Weight/drug effects , Disease Models, Animal , Fibrosis/prevention & control , Glomerular Filtration Rate , Glomerulonephritis/prevention & control , Kidney/drug effects , Kidney Diseases/prevention & control , Proteinuria/diagnosis , Pyridones/pharmacology , Sclerosis/prevention & control , Time Factors
9.
Article in English | IMSEAR | ID: sea-22669

ABSTRACT

BACKGROUND & OBJECTIVES: Mortality due to Plasmodium falciparum infection remains high in India, hence any modality of treatment which can improve the outcome of this disease is worth exploring. The present study was undertaken to see whether addition of an oral iron chelator, deferiprone (L1) to the conventional treatment regime for P. falciparum infection improves the clinical course and final outcome. METHODS: In this prospective, randomised double blind trial, 45 consecutive patients with P. falciparum infection were randomised into two groups. Patients in Group I (control group, 21 patients) received standard quinine and doxycycline therapy along with supportive therapy and placebo capsules for 10 days. Patients in Group II (24 patients) received the same treatment as Group I but in place of placebo capsule received deferiprone capsules 75 mg/kg/day in 12 hourly divided doses. The parameters evaluated included the time taken in resolution of parasitaemia, fever and coma, differences in final outcome i.e., death or other severe complications, and side effects and deferiprone tolerance. RESULTS: Four patients in Group I and two in Group II died (P > 0.05). The resolution of fever and coma was significantly faster in Group II (P < 0.05) and parasitaemia cleared 24 h earlier in this Group. The drug was well tolerated and had no side effects. INTERPRETATION & CONCLUSION: Deferiprone (L1) seems to be a promising agent as an adjuvant in the treatment for severe P. falciparum malaria infection.


Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Animals , Antimalarials/therapeutic use , Coma , Double-Blind Method , Doxycycline/therapeutic use , Drug Therapy, Combination , Female , Humans , India , Iron Chelating Agents/pharmacology , Malaria, Falciparum/drug therapy , Male , Middle Aged , Placebos , Plasmodium falciparum/drug effects , Prospective Studies , Pyridones/pharmacology , Quinine/therapeutic use
12.
Indian J Pediatr ; 1993 Jul-Aug; 60(4): 485-507
Article in English | IMSEAR | ID: sea-82323

ABSTRACT

In the last few years we have witnessed the emergence of oral chelation which is a new form of therapy for transfusional iron-loaded patients in thalassaemia and other refractory anaemias. The need for a cheap, non-toxic, orally effective iron chelator is paramount because it could potentially save the lives of many thousands of patients. At present, less than 10% of the patients requiring iron chelation therapy worldwide receive the widely used chelating drug desferrioxamine (DF) because of its high cost, oral inactivity and toxicity. The most promising oral iron chelator is 1, 2-dimethyl-3-hydroxypyrid-4-one (L1 or INN: Deferiprone), which has so far been taken by over 450 patients in 15 countries, and in some cases daily for over 4 years with very promising results. L1 was shown at 50-100 mg/kg/day to be effective in bringing patients to negative iron balance. It increases urinary iron excretion, decreases serum ferritin levels and reduces liver iron in multi-transfused iron-loaded patients. Toxic side effects were mainly encountered at high doses (80-100 mg/kg/day) and include transient agranulocytosis (5 cases), transient musculoskeletal and joint pains (10-20%), gastric intolerance (2-6%) and zinc deficiency (1%). The incidence of these toxic side effects was reduced by using lower doses of 50-75 mg/kg/day. The overall efficacy and toxicity of L1 is comparable to that of DF in animals and humans. Further work is required for identifying susceptible individuals to L1 toxicity, and also optimum dose protocols of L1 which can maximise iron excretion and minimise the incidence of toxic side effects.


Subject(s)
Animals , Chelation Therapy , Erythrocyte Transfusion/adverse effects , Humans , Iron , Iron Chelating Agents/pharmacology , Multicenter Studies as Topic , Pyridines/therapeutic use , Pyridones/pharmacology , Thalassemia/therapy
13.
Hindustan Antibiot Bull ; 1992 Aug-Nov; 34(3-4): 104-7
Article in English | IMSEAR | ID: sea-2462

ABSTRACT

Three antimycotic drugs, viz., Miconazole nitrate, Econazole nitrate and ciclopirox olamine were tested singly and in combination of miconazole nitrate and Econazole nitrate, Miconazole nitrate and Ciclopirox olamine, and Econazole nitrate and Ciclopirox olamine to evaluate in vitro efficacy against Trichophyton mentagrophytes and Macrosporum nanum. The best efficacy was shown by Ciclopirox olamine (MIC 0.78 microgram/ml) and a combination of Miconazole nitrate and Econazole nitrate (MIC 0.78 microgram/ml).


Subject(s)
Antifungal Agents/pharmacology , Drug Therapy, Combination , Econazole/pharmacology , Miconazole/pharmacology , Microbial Sensitivity Tests , Pyridones/pharmacology , Trichophyton/drug effects
14.
Acta physiol. pharmacol. ther. latinoam ; 42(2): 61-73, 1992. ilus, tab
Article in English | LILACS | ID: lil-116655

ABSTRACT

En tiritas intactas de ventrículo de sapo, se estudió el efecto relajante o lusitrópico positivo de diferentes intervenciones qu aumentan el AMPc intracelular. El isoproterenol aumentó la tensión desarrollada (DT), la velocidad máxima de contracción (+T), y la velocidad máxima de relajación (-T aumentó proporcionalmente más que +T a concentraciones de isoproterenol desde 10-8 a 10-4M, por lo que la relación +T/-T disminuyó significativamente. Una dosis única de isoproterenol (3x10**-8M) aumentó significativamente los niveles de AMPc desde 0.174 ñ 0.022 a 0.329 ñ pmoles/mg peso húmedo y produjo un aumento en la contractilidad de 69 ñ 13% y una disminución de +T/-T de 18.5 ñ 4.55%. La administración de 10**-3M de dibutiril AMPc(dAMPc) aumentó significativamente DT y +T y disminuyó significativamente la relación +T/-T. Efectos similares produjo la administración de milrinona, un inhibidor específico de la fosfodiesterasa de AMPc. La papaverina, un inhibidor inespecífico de fosfodiesterasas, no produjo aumentos en +T, pero aumentó significativamente -T. En trabéculas desprovistas químicamente de membrana, la sensibilidad al calcio de las proteínas contráctiles aumentó significativamente por la administración de 10**-5M del inhibidor de fosfodiesterasa 3-isobutil-1-metil-xantina (IBMX). La administración de 10**-3M de dAMPc no afectó la sensibilidad al calcio de las trabéculas desprovistas de membrana. Sin embargo la misma concentración de dAMPc produjo una disminución en la sensibilidad al calcio de las proteínas contráctiles cuando se administró en presencia de IBMX o de papavarina. Los resultados indicarían que el efecto relajante del isoproterenol es mediado en el ventrículo de sapo por un aumento en los niveles de AMPc intracelular. Estos resultados sugieren además que la disminución de la sensibilidad al calcio de los miofilamentos podría ser un mecanismo por el que el AMPc produce su efecto relajante


Subject(s)
Animals , Bucladesine/pharmacology , Calcium/metabolism , Myocardial Contraction , Bufo arenarum , Isometric Contraction , Isoproterenol/pharmacology , Papaverine/pharmacology , Pyridones/pharmacology , Heart Ventricles/physiology
15.
Braz. j. med. biol. res ; 23(11): 1069-78, 1990.
Article in English | LILACS | ID: lil-91477

ABSTRACT

1-The acute administration of milrinone, a positive inotropic vasodilator agent, improves resting hemodynamic function and maximal and submaximal metabolic rsponses to exercice in patients with severe congestive heart failure. 2. to determine whether the improvement in exerecise capacity induced by milrinone administration can be predicted by its acute positive inotropic and/or vasodilator effects at rest, milrinone was adminstered intravenously (progressive doses of 1.5 to 75 microng/Kg) to 15 patients with heart failure (functional classes III and IV, New York Heart Association) at rest, and during maximal upright exercise testing on a cycke ergometer. Serum drug levels were matched for the resting and exercise tests. Drug administration for exercise tests was placebo-controlled and double-blind. 3. At rest, milrinone administration caused substantial decreases in right atrial pressure (-53%), left ventricular end-diastolic pressure (-30%), and systemic vascular resistance (-35%); and increases in cardiac index (+59%), peak positive dP/dt (+20%) and stroke work index (+51%). Administration of milrinone during exercise resulted in a 15% increase in peak oxygen uptake and a 16% increase in anaerobic threshold. However, none of the changes in resting hemodynamic function correlated significantly in magnitude with the changes in peak oxygen uptake and anaerobic threshold. 4. Thus, the acute improvement in exercise capacity that occus with milrinone is not predicted by the positive inotropic or vasodilator effects of the drug at rest


Subject(s)
Humans , Middle Aged , Male , Female , Exercise Test , Heart Failure/physiopathology , Hemodynamics/drug effects , Pyridones/pharmacology , Vasodilator Agents/pharmacology , Anaerobic Threshold/drug effects , Heart Failure/drug therapy , Injections, Intravenous , Pyridones/administration & dosage
16.
CCS ; 10(3/4): 229-36, jul.-dez. 1988. tab
Article in English | LILACS | ID: lil-116440

ABSTRACT

A aplicaçäo de deltametrina em ninfas de T.Infestans, nas doses de 0,0483 ou 0,0966 mg i. a./g de inseto, em exemplares ja expostos a infecçäo por T.Cruzi,reduz significativamente a taxa de eliminaçäo de tripomastigotas nas dejeçöes. A aplicaçäo de 0,0966 mg/g, 3 ou 7 dias antes da exposiçäo a T. Cruzi, nao influenciou significativamente a taxa de eliminaçäo


Subject(s)
Animals , Pyridones/pharmacology , Trypanosoma cruzi/drug effects , Pyridones/administration & dosage , Time Factors , Triatoma , Triatominae
17.
Acta physiol. pharmacol. latinoam ; 38(2): 193-211, 1988. ilus, tab
Article in English | LILACS | ID: lil-80443

ABSTRACT

Se estudió el efecto inotrópico de milrinona en preparaciones de corazón aislado de rata y de gato. En aurícula de rata con latido espontáneo se observó un efecto inotrópico positivo inicial dosis-dependiente, con aumento máximo en la tensión desarrolada (TD) de +26.5 ñ 2.8% con la dosis de 25 microng/ml y un aumento máximo de la frecuencia espontánea de 60 ñ 6% con la dosis de 80 microng/ml. Sin embargo, en aurícula de rata elétricamente dirigida, el aumento máximo de TD fue de +39.2 ñ 3.4%. La diferencia entre ambas preparaciones puede ser consecuencia del fenómeno de la escalera negativa que limita el aumento en TD en aurícula de rata con latido espontáneo. En aurícula aislada de gato eléctricamente dirigida, el efecto inotrópico positivo de milrinona se inició con la dosis de 0.5 microng/ml y el efecto máximo (36% de aumento en TD) se obtuvo con la dosis de 8 microng/ml. En músculo papilar de gato la relación dosis-respuesta se desplazó hacia arriba y hacia la ezquierda si se compara con preparaciones de aurícula de rata, y el aumento máximo de la TD fue de alrededor de 90%. En preparaciones de aurículas aisladas de rata el etanol (22 y 44 mM) produjo una significativa disminución de la TD dosis-relacionada, que fue revertida por milrinona y su relación dosis-efecto fue similar tanto en presencia como en ausencia de etanol. En músculo papilar aislado de gato, el etanol (rr mM) produjo una disminución de la TD de 15.1 ñ 1.8%. Milrinona en concentraciones bajas de hasta 8 microng/ml prod


Subject(s)
Cats , Rats , Animals , Male , Female , Cardiotonic Agents/pharmacology , Ethanol/antagonists & inhibitors , Heart Rate , Halothane/antagonists & inhibitors , Pyridones/pharmacology , 3',5'-Cyclic-AMP Phosphodiesterases/antagonists & inhibitors , Myocardial Contraction , Ethanol/pharmacology , Halothane/pharmacology , Heart Atria/drug effects , Papillary Muscles
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