Medicinas tradicionales andinas y su despenalización: entrevista con Walter Álvarez Quispe / Decriminalizing traditional Andean medicine: an interview with Walter Álvarez Quispe

Walter Álvarez Quispe, terapeuta kallawaya y biomédico especializado en cirugía general y ginecología, presenta la lucha de los terapeutas tradicionales y alternativos por la depenalización de estos sistemas médicos andinos realizada entre 1960 y 1990. Bolivia se torna el primer país en América Latina y el Caribe en despenalizar la medicina tradicional antes de los planteamientos de la Conferencia Internacional sobre Atención Primaria de Salud (Alma-Ata, 1978). Los datos aportados por el entrevistado aseguran que los logros alcanzados, principalmente por los kallawayas, responden a un proyecto propio y autónomo. Estas conquistas no se deben a las políticas oficiales de interculturalidad en salud, aunque busquen atribuirse para sí los logros alcanzados.

Walter Álvarez Quispe, a Kallawaya healer and biomedical practitioner specializing in general surgery and gynecology, presents the struggle of traditional and alternative healers to get their Andean medical systems depenalized between 1960 and 1990. Bolivia was the first country in Latin America and the Caribbean to decriminalize traditional medicine before the proposals of the International Conference on Primary Health Care (Alma-Ata, 1978). The data provided by the interviewee show that the successes achieved, mainly by the Kallawayas, stem from their own independent initiative. These victories are not the result of official policies of interculturality in healthcare, although the successes achieved tend to be ascribed to them.

H[2] receptor activity; effect in isolated rabbit heart

Histamine can stimulate the heart by directly interacting with cardiac histamine receptors. In the present study we have investigated the H[2] receptor activity in isolated rabbit heart. Cimetidine, a specific H[2] receptor antagonist was used. The isolated heart was mounted in langendroff apparatus. The heart was perfused at a constant pressure with oxygenated Ringer's Locke solution. H[2] receptor antagonist produces negative inotropic effect in the presence of histamine. This indicates that H[2] receptors are present in rabbit heart, and plays a role in mediation of positive inotropic effect produced through CAMP by histamine

Avaliações objetiva e subjetiva da obstrução nasal em crianças e adolescentes com rinite alérgica / Objective and subjective assessments of nasal obstruction in children and adolescents with allergic rhinitis

OBJETIVO: Relacionar a avaliação objetiva da obstrução nasal por rinometria acústica (volume dos cinco primeiros centímetros da cavidade nasal) e rinomanometria anterior ativa (resistência nasal total) com a avaliação subjetiva (escore de obstrução). MÉTODO: Participaram do estudo 30 pacientes (7 a 18 anos) com rinite alérgica persistente e 30 controles. O escore foi referido para cavidade nasal total e narinas em separado. As três variáveis foram mensuradas nos momentos basal e após indução de obstrução nasal. RESULTADOS: Houve correlações significantes e negativas entre resistência e volume nasal em todos os grupos e situações de avaliação, exceto para narina mais obstruída, grupo controle, pós-obstrução. Para a cavidade nasal total, não houve correlação significante entre as variáveis objetivas e subjetiva, exceto entre escore e volume na cavidade nasal total no grupo controle pós-obstrução. Na narina mais obstruída, houve correlação significante e negativa para escore e resistência e significante e positiva para escore e volume nasal no grupo total, momento basal. Não houve diferença nítida nos coeficientes de correlação entre pacientes e controles, e estes não se alteraram após a indução de obstrução nasal. CONCLUSÕES: Avaliação objetiva da obstrução nasal não apresentou correlação significativa com a avaliação subjetiva na cavidade nasal total, mas sim na avaliação unilateral. Houve correlação entre avaliações objetivas. Rinite alérgica ou obstrução nasal aguda não interferiram na correlação entre as avaliações objetiva e subjetiva da obstrução nasal. Sugere-se utilidade no acréscimo de métodos objetivos para avaliação da obstrução nasal em pesquisas e, na sua impossibilidade, avaliação das narinas em separado.

OBJECTIVE: To correlate objective assessment of nasal obstruction, as measured by acoustic rhinometry (volume of the first 5 cm of the nasal cavity) and active anterior rhinomanometry (total nasal airway resistance), with its subjective evaluation (obstruction scores). METHOD: Thirty patients, aged 7 to 18 years, with persistent allergic rhinitis and thirty controls were enrolled. The obstruction score was reported for the whole nasal cavity and for each nostril separately. The three variables were measured at baseline and after induction of nasal obstruction. RESULTS: There were significant and negative correlations between resistance and nasal volume in all groups and scenarios, except for the most obstructed nostril, in the control group, post-obstruction. For the whole nasal cavity, there was no significant correlation between objective and subjective variables except between score and total nasal cavity volume in the control group, post-obstruction. Regarding the most obstructed nostril, we found a significant negative correlation between score and resistance and a significant positive correlation between score and volume for the total group at baseline. There were no clear differences in the correlation coefficients found in patients and controls. The correlation coefficients did not change after induction of nasal obstruction. CONCLUSIONS: Objective assessment of nasal obstruction did not correlate significantly with subjective evaluation for the nasal cavity as a whole, but there was a correlation for unilateral assessments. There was correlation between the objective evaluations. Allergic rhinitis and acute induction of nasal obstruction did not affect the correlation between objective and subjective assessments of nasal obstruction. Addition of an objective method for evaluation of nasal obstruction could be useful in the research setting; if no such method can be used, each nostril should be evaluated separately.

Human umbilical artery smooth muscle exhibits a 2-APB-sensitive capacitative contractile response evoked by vasoactive substances and expresses mRNAs for STIM, Orai and TRPC channels

After depletion of intracellular Ca2+ stores the capacitative response triggers an extracellular Ca2+ influx through store-operated channels (SOCs) which refills these stores. Our objective was to explore if human umbilical artery smooth muscle presented this response and if it was involved in the mechanism of serotonin- and histamine-induced contractions. Intracellular Ca2+ depletion by a Ca2+-free extracellular solution followed by Ca2+ readdition produced a contraction in artery rings which was inhibited by the blocker of Orai and TRPC channels 2-aminoethoxydiphenyl borate (2-APB), suggesting a capacitative response. In presence of 2-APB the magnitude of a second paired contraction by serotonin or histamine was significantly less than a first one, likely because 2-APB inhibited store refilling by capacitative Ca2+ entry. 2-APB inhibition of sarcoplasmic reticulum Ca2+ release was excluded because this blocker did not affect serotonin force development in a Ca2+-free solution. The PCR technique showed the presence of mRNAs for STIM proteins (1 and 2), for Orai proteins (1, 2 and 3) and for TRPC channels (subtypes 1, 3, 4 and 6) in the smooth muscle of the human umbilical artery. Hence, this artery presents a capacitative contractile response triggered by stimulation with physiological vasoconstrictors and expresses mRNAs for proteins and channels previously identified as SOCs.

Preconditioning of the response to ischemia/ reperfusion-induced plasma leakage in hamster cheek pouch microcirculation

OBJECTIVE: Ischemic preconditioning and some drugs can protect tissues from injury by preserving microcirculation. This study evaluated vascular permeability in a hamster cheek pouch preparation using either short ischemic periods or bradykinin as preconditioning stimuli followed by 30 min of ischemia/reperfusion. METHOD: Sixty-six male hamsters were divided into 11 groups: five combinations of different ischemic frequencies and durations (one, three or five shorts periods of ischemia, separated by one or five minutes) with 10 min intervals between the ischemic periods, followed by 30 min ischemia/reperfusion; three or five 1 min ischemic periods with 10 min intervals between them followed by the topical application of histamine (2 µM); bradykinin (400 nM) followed by 30 min of ischemia/reperfusion; and three control groups (30 min of ischemia/reperfusion or histamine or bradykinin by themselves). Macromolecular permeability was assessed by injection of fluorescein-labeled dextran (FITC-dextran, MW= 150 kDa; 250 mg/Kg body weight), and the number of leaks/cm2 was counted using an intravital microscope and fluorescent light in the cheek pouch. RESULTS: Plasma leakage (number of leaks/cm²) was significantly reduced by preconditioning with three and five 1 min ischemic periods, one and three 5 min ischemic periods and by bradykinin. Histamine-induced macromolecular permeability was also reduced after three periods of 5 min of ischemia. CONCLUSION: Short ischemic periods and bradykinin can function as preconditioning stimuli of the ischemia/reperfusion response in the hamster cheek pouch microcirculation. Short ischemic periods also reduced histamineinduced macromolecular permeability.

Urticaria aguda / Acute urticaria

La urticaria es una reacción de la piel caracterizada clínicamente por la aparición de elevaciones cutáneas eritematosas o blanquecinas, edematosas, pruriginosas y transitorias, que pueden localizarse en cualquier parte de la superficie cutáneao en las mucosas. Su etiología es variada y sus mecanismos etiopatogénicos también suelen ser múltiples. La lesión típica es el habón o roncha, el cuál cambia de lugar en horas, su forma y tamaño son variables, puede persistir minutos, horas o semanas. La mayoría de las urticarias no presenta sintomatología sistémica. Suele clasificarse regularmente en urticaria aguda, cuando lleva menos de 6 semanas de aparición, y en urticaria crónica, cuando lleva más de 6 semanas. El diagnóstico es fundamentalmente clínico. Es una entidad frecuente que por su gran expresividad motivan constantes y reiteradas consultas a los servicios de urgencia. En este artículo se examinarán los mecanismos que llevan a la urticaria y angioedema, y se revisará la patogénesis, los aspectos clínicos, los estudios de laboratorio necesarios y el tratamiento de la urticaria aguda.

The urticaria is a skin reaction characterized clinically by the on set of erythematous skin elevations or whitish, oedematous,pruritic and transient, you can locate anywhere on the surface of the skin or the mucous membranes. Its etiology is varied and its mechanisms etiopathogenic also tend to be multiple. The typical lesion is the wheal or bump, which changes from place with inhours, its size and shape are variable, may persist for minutes, hours or weeks. The majority of the hives does not pose systemic symptoms. Usually qualify regularly in acute urticaria, when it takes less than 6 weeks of appearance, and chronic urticaria, when it takes over 6 weeks. The diagnosis is primarily clinical. Itis a common entity that by their expressivity motivate constants and repeated consultations to emergency services. This article will xamine the mechanisms that lead to angioedema and urticaria, he pathogenesis, clinical aspects, necessary laboratory studies and eatment.

Vimentin and laminin are altered on cheek pouch microvessels of streptozotocin-induced diabetic hamsters

OBJECTIVE: Normal endothelial cells respond to shear stress by elongating and aligning in the direction of fluid flow. Hyperglycemia impairs this response and contributes to microvascular complications, which result in deleterious effects to the endothelium. This work aimed to evaluate cheek pouch microvessel morphological characteristics, reactivity, permeability, and expression of cytoskeleton and extracellular matrix components in hamsters after the induction of diabetes with streptozotocin. METHODS: Syrian golden hamsters (90-130 g) were injected with streptozotocin (50 mg/kg, i.p.) or vehicle either 6 (the diabetes mellitus 6 group) or 15 (the diabetes mellitus 15 group) days before the experiment. Vascular dimensions and density per area of vessels were determined by morphometric and stereological measurements. Changes in blood flow were measured in response to acetylcholine, and plasma extravasation was measured by the number of leakage sites. Actin, talin, α-smooth muscle actin, vimentin, type IV collagen, and laminin were detected by immunohistochemistry and assessed through a semiquantitative scoring system. RESULTS: There were no major alterations in the lumen, wall diameters, or densities of the examined vessels. Likewise, vascular reactivity and permeability were not altered by diabetes. The arterioles demonstrated increased immunoreactivity to vimentin and laminin in the diabetes mellitus 6 and diabetes mellitus 15 groups. DISCUSSION: Antibodies against laminin and vimentin inhibit branching morphogenesis in vitro. Therefore, laminin and vimentin participating in the structure of the focal adhesion may play a role in angiogenesis. CONCLUSIONS: Our results indicated the existence of changes related to cell-matrix interactions, which may contribute to the pathological remodeling that was already underway one week after induction of experimental diabetes.

Mechanism of spasmolytic activity of a fraction of Sarcostemma brevistigma Wight.

The effect of chloroform soluble fraction (F-A) of twigs of Sarcostemma brevistigma on contractions induced by KCl, histamine, and acetylcholine in the isolated guinea pig ileum and taenia coli smooth muscles has been evaluated. F-A (19.5 microg/ml) significantly inhibited the contraction induced by 40 mM KCl to the extent of 87.6% in the isolated guinea pig ileum. In the isolated guinea pig ileum, F-A (64.3 and 59.2 microg/ml) significantly inhibited the contractions induced by acetylcholine and histamine to the extent of 85 and 83% respectively. In the isolated guinea pig taenia coli, F-A (65.2 microg/ml) significantly inhibited the contraction induced by 40 mM KCl to the extent of 96.0%. The inhibitory effect of F-A (40 microg/ml) on the isolated guinea pig taenia coli was reduced by Bay K 8644 (10(-6) M) to the extent of 61.6 from 73.6%. These results suggest that the F-A may exhibit smooth muscle relaxant activity by blocking the Ca2+ channels.

Histamine and spontaneously released mast cell granules ffect the cell growth of human hepatocellular carcinoma cells

The role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H1 and H2 and that the selective H1 antagonist terfenadine reverted the histamine-induced inhibition of HuH-6 cell growth, whereas the selective H2 antagonist ranitidine inhibited the histamine-induced cell growth of HA22T/VGH cells. We demonstrated that histamine down-regulated the expression of beta-catenin, COX-2 and survivin in HuH-6 cells and that this was associated with caspase-3 activation and PARP cleavage. On the contrary, in HA22T/VGH cells expression of survivin and beta-catenin increased after treatment with granule remnants and histamine. Overall, our results suggest that mediators stored in mast cell granules and histamine may affect the growth of liver cancer cells. However, mast cells and histamine may play different roles depending on the tumor cell features. Finally, these data suggest that histamine and histamine receptor agonists/antagonists might be considered as "new therapeutic" drugs to inhibit liver tumor growth.

Airways are More Reactive to Histamine than to Methacholine in Patients with Mild Airway Hyperresponsiveness, Regardless of Atopy

BACKGROUND: The airway muscles from allergen-sensitized animals in vitro show a heightened response to histamine, but not to carbachol. This study investigated whether the airway responsiveness to histamine in vivo is comparable to that of methacholine in human subjects with varying degrees of atopy. METHODS: One-hundred-and-sixty-eight consecutive adult asthma patients or volunteers underwent bronchoprovocation tests to both histamine and methacholine after determining their blood eosinophil counts, serum total IgE levels and skin test reactivity to 10 common aeroallergens. RESULTS: The responsiveness to histamine was significantly related to that to methacholine (r=0.609, p<0.001), but many individuals with a negative methacholine test response showed a positive response to histamine. The histamine-bronchial reactivity index (BRindex) was significantly higher than the methacholine-BRindex in subjects with a positive response to none (n=69, p<0.01) or only one (n=42, p<0.001) of histamine and methacholine, while there was no significant difference in the subjects with positive responses to both of them (n=57). The histamine-BRindex was significantly higher than the methacholine-BRindex in the subjects with mild histamine hyperresponsiveness (n=58, 1.28+/-0.01 vs. 1.20+/-0.02, respectively, p<0.001). Both histamine and methacholine responsiveness was significantly related to the atopy markers. However, the histamine-BRindex/methacholine-BRindex ratio of the atopics was not significantly different from that of the non-atopics. CONCLUSIONS: The airway responsiveness to histamine is comparable to that of methacholine in the subjects with positive responses to both histamine and methacholine, but the airway responsiveness to histamine is greater than that to methacholine in those subjects with mild airway hyperresponsiveness, regardless of atopy.

Antioxidant activity of hydroalcoholic leaf extract of ocimum sanctum in animal models of peptic ulcer.

In the present study, a hydroalcoholic extract of ocimum sanctum leaves has been investigated for its antioxidant activity in animal models of peptic ulcer with the aim of exploring a possible correlation between its antioxidant and antiulcer activities. Gastric ulcers were produced in rats by ethanol treatment and pyloric ligation whereas duodenal ulcers were produced in guinea pigs by histamine treatment. The animals were divided into six groups of six animals each in all these three models of peptic ulcer. Group I served as diseased control in which distilled water (10 ml/kg) orally was administered as placebo. Group II, III and IV received the test drug (ocimum sanctum leaf extract) in doses of 50 mg/kg, 100 mg/kg and 200 mg/ kg respectively orally once daily for 7 days. Group V was administered ranitidine (10 mg/kg orally) once daily for 7 days and served as standard for comparison. Group VI consisted of healthy control for baseline malondialdehyde (MDA) and superoxide dismutase (SOD) levels. The antioxidant activity was by evaluated estimating plasma MDA in ethanol treated rats and histamine treated guinea pigs and estimating SOD in pyloric ligated rats and histamine treated guinea pigs. In ethanol treated rats, ocimum sanctum leaf extract (100 mg/kg & 200 mg/kg) significantly decreased the levels of MDA to 2.45 +/- 0.29 nmole/ml and 2.40 +/- 0.14 nmole/ml respectively in comparison to 4.87 +/- 0.06 in the diseased control. Similarly, in the histamine treated guinea pig group, the same doses of the extract significantly lowered the levels of MDA to 2.45 +/- 0.12 nmole/ml and 2.37 +/- 0.16 nmole/ml respectively when compared to 4.66 +/- 0.11 in the diseased control. The extract (100 mg/kg & 200 mg/ kg) also increased the levels of SOD in pyloric ligated rats to 1.78 +/- 0.12 U/ml and 1.89 +/- 0.08 U/ml respectively when compared to 1.29 +/- 0.06 U/ml in the diseased control. In the histamine treated guinea pig group also, the same doses of the extract produced a rise in the SOD levels to 2.10 +/- 0.11 U/ml and 2.20 +/- 0.14 U/ml respectively when compared to 1.32 +/- 0.07 in the diseased control. Since lowered levels of MDA and increased levels of SOD signify antioxidant activity, the antiulcer activity of ocimum sanctum might be due to this mechanism.

Inhibition of tryptase release from human colon mast cells by histamine receptor antagonists.

The main objective of this study was to investigate the ability of histamine receptor antagonists to modulate tryptase release from human colon mast cells induced by histamine. Enzymatically dispersed cells from human colon were challenged with histamine in the absence or presence of the histamine receptor antagonists, and the tryptase release was determined. It was found that histamine induced tryptase release from colon mast cells was inhibited by up to approximately 61.5% and 24% by the H1 histamine receptor antagonist terfenadine and the H2 histamine receptor antagonist cimetidine, respectively, when histamine and its antagonists were added to cells at the same time. The H3 histamine receptor antagonist clobenpropit had no effect on histamine induced tryptase release from colon mast cells at all concentrations tested. Preincubation of terfenadine, cimetidine or clobenpropit with cells for 20 minutes before challenging with histamine did not enhance the ability of these antihistamines to inhibit histamine induced tryptase release. Apart from terfenadine at 100 microg/ml, the antagonists themselves did not stimulate tryptase release from colon mast cells following both 15 minutes and 35 minutes incubation periods. It was concluded that H1 and H2 histamine receptor antagonists were able to inhibit histamine induced tryptase release from colon mast cells. This not only added some new data to our hypothesis of self-amplification mechanisms of mast cell degranulation, but also suggested that combining these two types of antihistamine drugs could be useful for the treatment of inflammatory bowel disease (IBD).

Influence of influenza viral infection on airway smooth muscle activity.

The contractility of airway smooth muscle (ASM) plays an important role in pathophysiology of several bronchial disorders. Increased contraction of ASM during asthma and respiratory viral infection has been attributed to the release of mediators acting through different receptors. In the present study, influence of influenza type A virus (H1N1) infection has been examined on ASM responsiveness to various bronchoactive agents e.g. adenosine, histamine, 5-hydroxytryptamine (5-HT) and isoproterenol in an organ bath set up for isolated tissue preparation. The contractile effect of adenosine, histamine and 5-HT was enhanced, however, relaxant response of isoproterenol was attenuated with the duration following viral exposure. The most prominent response was observed 48 to 72 hr after infection and tissues from multiple exposure to virus infected animals showed the maximum contractile response. Results demonstrated the deleterious effect of viral infection on ASM function and the findings will be helpful in understanding the mechanism of influenza virus induced bronchoconstriction.

Estudo da açäo antiinflamatória e potência ulcerogênica de compostos mesoiônicos, 1,4-difeniltiossemicarbazida e derivados / Study of the antiinflammatory action and ulcerogenic potency of mesoionics, 1,4-diphenylthiosemicarbazide compounds and derivatives

Os compostos 1,4-difeniltiossemicarbazida (DTSC), derivados (`IR IND. 1ï; `IR IND. 2ï e `IR IND. 3ï) e mesoiônicos (`MIR IND. 1ï, `RMIR IND. 1ï e `RMIR IND. 3ï) foram avaliados quanto à atividade antiinflamatória. os compostos DTSC, `IR IND. 1ï, `IR IND. 2ï, e `RMIR IND. 1ï inibiram significativamente o pico máximo do edema induzido por carragenina em 82 por cento, 72 por cento, 34 por cento e 78 por cento, respectivamente. Porém, somente os derivados mesoiônicos inibiram o edema induzido por dextrano. Já no edema desencadeado por histamina, somente o composto IR, não foi capaz de antagonizar de maneira significativa a ação da histamina...

Revisión de los medicamentos antivertiginosos / a review of antivertigo medication

Objetivo. Valorar la información existente sobre los efectos de las sustancias antivertiginosas, basados en la bibliografía asequible. Información. Se localizaron artículos pertinentes en Medline y en revistas obtenidas en la ciudad de México. Selección del material. Los artículos se seleccionaron en base a su aparente consistencia interna y su relación con el propósito de la revisión. Conclusión. Se evaluaron 22 substancias pertenecientes a 8 grupos farmacológicos (colinérgicos, antihistamínicos, GABAérgicos, bloqueadores de canales de calcio, serotoninérgicos, hemorreológicos, antiagregantes plaquetarios y diuréticos) útiles en diversos padecimientos vertiginosos. Se advirtió la necesidad de un método objetivo y cuantitativo para valorar resultados de ensayos clínicos en humanos. Mientra esto no ocurra, tendremos que usar los medicamentos en base de una información veraz, confiable y basada sólidamente en la farmacología estudiada en experimentos con animales y en la valoración cuidadosa de los efectos -buenos y malos- observados en nuestros pacientes.

Possible role of histamine receptors in the central regulation of immune responses.

The present study was designed to delineate the role of H1- and H2-histamine receptors in the neuro-immune regulation in rats. The effects of H1- and H2-receptor antagonists on humoral and cell-mediated immune (HI and CMI) responses were investigated after intraperitoneal (i.p.) and intra-cerebroventricular (i.c.v.) administration. HI response was assayed by anti-sheep red blood cell (SRBC) antibody titre in presence and absence of 2-mercaptoethanol (2-ME). The CMI responses were evaluated by delayed type hypersensitivity (DTH) reaction (in vivo), i.e., measurement of footpad thickness, and lymphokine activity such as leucocyte migration inhibition (LMI) test (in vitro). On i.p. administration, both H1- (pheniramine and astemizole) and H2-receptor antagonists (ranitidine and cimetidine) were observed to produce significant enhancement of anti-SRBC antibody response. However, only H2- and not H1-receptor blockers were observed to stimulate CMI response significantly. When administered by icv route, only H2-receptor antagonists caused a statistically significant increase in both HI and CMI responses, while the H1-receptor blockers failed to modify the same. Thus, H2-receptors appear to play a major role in the histaminergic mechanisms involved in immunomodulation both at the level of immunocompetent cells active in the peripheral tissues as well as through the central nervous system structures involved in the central regulation of neuro-immune interaction.

Efeito da histamina na regeneração hepática: estudo experimental em ratos / Effect of histamin in liver regeneration: experimental study in rats

Muitas substâncias têm sido utilizadas após hepatectomias parciais a fim de conhecer como elas atuam sobre o processo de regeneração hepática. Adequado fluxo sangüíneo parece ter muita importância neste processo. Autores descreveram, após hepatectomias em ratos, elevação dos níveis plasmáticos de histamina. Substâncias inibidoras da histidina-decarboxilase e da histaminase leva a elevação da histamina endógena com vasodilatação sinusoidal e aceleração da regeneração hepática. No presente estudo busca-se conhecer a influência da histamina exógena administrada à ratos parcialmente hepatectomizados. Utilizaram-se 32 ratos Wistar que sofreram hepatectomia de aproximadamente 67 por cento da víscera. Os animais do grupo experimento receberam por via subcutânea 0,5 mg/Kg/dia de histamina e os do grupo controle igual volume de solução salina isotônica. As aferições foram realizadas com 36 horas e 7 dias. A avaliação do peso da víscera não mostrou diferença entre os grupos. O número de figuras de mitose em 10 campos foi maior no grupo experimento com 36 horas (p=0,010). No sétimo dia o número delas era semelhante nos dois grupos. Concluiu-se que a administração de histamina exógena, talvez pela sua vida média curta, aumenta o número de figuras de mitose no início do processo, não interferindo na regeneração ao final de 7 dias.

Influence of antibiotics on the mechanical responses of guinea-pig ileum to acetycholine and histamine

The side effects of antibiotics have been extensively described during the last decades, however, their role on digestive motility must be better investigated. Following a line research, the influence of penicillin, chloranfenicol tetracycline and gentamicine on longitudinal snooth muscle response to acetylcholine and histamine were studied on guinea-pig ileum. There were no differences between the responses before and after the addition of each antibiotic. Further investigations must be performed in order to find a possible influence of antibiotics on digestive motility.

The effect of L-arginine on guinea-pig and rabbit airway smooth muscle function in vitro

We have investigated the effects of L-arginine, D-arginine and L-lysine on airway smooth muscle responsiveness to spasmogens in vitro. Both L-arginine and D-arginine (100 mM) significantly reduced the contractile potency and maximal contractile response to histamine but not to methacholine or potassium chloride in guinea-pig epithelium-denuded isolated trachea. Similarly, the contractile response to histamine was significantly reduced by L-arginine (100 mM) in rabbit epithelium-denuded isolated bronchus. The amino acid L-lysine (100 mM) failed to significantly alter the contractile potency of histamine in guinea-pig isolated trachea (P> 0.05). In guinea-pig isolated trachea precontracted with histamine, both L-arginine and D-arginine produced a concentration-dependent relaxation which was not significantly altered by epithelium removal or by the presence of the nitric oxide synthase inhibitor, N G -nitro L-arginine methyl ester (L-NAME; 50 µM). Thus, at very high concentrations, arginine exhibit a non-competitive antagonism of histamine-induced contraction of isolated airway preparations that was independent of the generation of nitric oxide and was not dependent on charge. These observations confirm previous studies of cutaneous permeability responses and of contractile responses of guinea-pig isolated ileal smooth muscle. Taken together, the data suggest that high concentrations of arginine can exert an anti-histamine effect