Blood pressure variations in Subjects with different Haemoglobin Genotypes

Previous studies on low blood pressure in patients with homozygous sickle cell disease (SCD) have sought various hypotheses on the mechanism of their low blood pressure. However, these studies have not compared the role of the single inheritance of the s-gene in the variations in blood pressures as well as relating the blood pressures in different haemoglobin (HB) genotypes to each other. Blood pressures in 20 steady and crisis states SCD patients respectively with 40 apparently healthy heterozygous HB AS and HB AA genotype (age and sex –matched). They were aged between 20 and 40 years. Results showed a significantly (p<0.05) lower blood pressure (systolic and diastolic) in SCD in stable (but not in crisis) state compared with the normal controls. The systolic blood pressures in control (HB AA) and SCD patients were 125.33 ± 2.25 versus 115.25 ± 2.9 (stable state); 125.33 ± 2.25 versus 124.83 ± 2.88 (crisis state, p>0.05), 82.33 ± 1.2 versus 72.25 ± 1.81 (stable state, p<0.05) and 82.33 ± 1.2 versus 99.5 ± 5.81 (crisis state, p<0.05). Also, HB AS subjects exhibited significantly higher diastolic pressure than HB AA and HB SS subjects during crisis. In conclusion, this study shows that systolic and diastolic blood pressures are lower in SCA patients in stable state (compared with control, HB AA subjects) but are relatively higher during crisis while diastolic blood pressure is significantly higher in HB AS than HB AA and HB SS subjects in crisis. Further work needs to be done to determine the mechanism for this variation.Keywords: Blood pressure, Hemoglobin, Genotypes Sickle cell anemi

Variations in Responses of Vascular Smooth Muscles to Na-K Pump Inhibition

There is a paucity of information concerning the variability of Na+-K+-ATPase activity in various vascular preparations. In this study, we have investigated, comparatively, K+-induced relaxation in different vascular tissues, to establish the heterogeneity of the activity of this enzyme. Isometric contractions of ring preparations of porcine tail artery and rat aorta as well as longitudinal strips of rat portal vein, mounted in 20ml organ baths were studied, under an initial load of 1g, at 37oCand pH of 7.4. The protocols examined were: Contractile responses to phenylephrine, 80mM K+ and K+-free exposure as well as relaxation responses to K+ following exposure to K+-free PSS. Phenylephrine, 80mM K+ and K+-free exposure elicited contractile responses in all tissue preparations. Following 30 minutes exposure to K+-free PSS and pre-contraction induced by EC70 (M) concentration of phenylephrine, addition of 5mM K+ elicited relaxation responses only in rat aortic rings and rat portal vein strips. Rings from Porcine tail artery failed to relax to K+ in all experiments. The magnitude of K+-induced relaxation was in the order: Rat Portal Vein > Rat Aorta. The times-to-peak of K+-free-induced contractile responses were 2.0 ± 0.0, 3.5 ± 0.5 and 6.25 ± 3.13 minutes for rat portal vein (n=6), rat aorta (n=6) and porcine tail artery (n=6), respectively. The magnitudes of relaxation in response to 5mM K+ for rat portal vein and rat aorta were 86.5 ± 16.75 and 60.00 ± 10.0%, respectively while the respective durations of K+-induced relaxation were: 30 ± 0 and 180 ± 22 seconds (n=6). The results suggest considerable heterogeneity in the activity of Na+-K+-ATPase enzyme in vascular smooth muscles from the rat portal vein, rat aorta and porcine tail artery.Keywords: Na+-K+-ATPase; Vascular Smooth Muscle; Rat aorta; Rat Portal Vein; Porcine Tail Arter

Effects of ginger (Zingiber officinale) on cadmium toxicity

Thirty six Winstar rats were divided into six equal groups and investigated for induced cadmium toxicity, and the detoxicating action of ginger on liver-accumulated cadmium. Group 1, the control, werefed with normal rat chow and water for six weeks. Group 2 were fed with normal rat chow and cadmium water (200 ppm Cd in water). Group 3 were fed with rat chow-ginger concentrate (95:5, w/w ratio) andwater, while Group 4 were fed with rat chow-ginger concentrate and cadmium water, all for six weeks. Group 5 were fed with normal rat chow and cadmium water initially for one week, followed by rat chowgingerconcentrate and water for five weeks; while Group 6 were fed with rat chow-ginger concentrate for one week, followed by normal rat chow and cadmium water for five weeks. Cadmium accumulated highly in rat livers without ginger administration, and raised serum glutamate oxaloacetatetransaminase (GOT) and glutamate pyruvate transaminase (GPT), while ginger lowered these parameters. Ginger had better therapeutic than prophylactic detoxication effects on liver cadmium accumulation, especially as further cadmium intake was stopped. It was concluded that cadmium detoxication by ginger was more effective therapeutically, than prophylactically, as further cadmium intake was avoided

Altered Vascular Reactivity Induced By Malaria Parasites

Objective: In this study, we have examined the possibility that there is altered vascular reactivity due to the direct interaction between parasitized erythrocytes and vascular endothelial cells. Method: Ring preparations of rat aorta were studied using standard in vitro techniques, the rings were mounted in 20 ml organ baths containing PSS under an initial load of 1g, maintained at 37°C at pH 7.4 and isometric contractions were recorded electronically. Rings were allowed 90 minutes to equilibrate before the commencement of the various protocols: *Dose responses to phenylephrine (PE) and other vasoactive agents (high-K+) *Acetylcholine (Ach) – induced relaxation in phenylephrine-contracted rings (pre-contraction was induced by EC70 concentration of phenylephrine) *Ach-induced relaxation in PE-precontracted, endothelium-denuded rings *Also, relaxation responses to acetylcholine was investigated through application of a single (EC70) concentration of acetylcholine in rings exposed to blood with varying concentrations and dilutions of parasitized blood and varying durations of exposure. Results: Incubation with parasitized blood resulted in a significant increase in maximum contractile response to phenylephrine in the rat aortic rings (p < 0.05) but no effect to the base line. Analysis of the whole dose-response curve (using paired t-test) showed a significant left-ward shift following the addition of parasitized blood (p < 0.05), EC70 (M) values increasing from 7 x 10-7 to 5 x 10-6 M. Follow-ing exposure to parasitized blood, the magnitude of Ach-induced relaxation responses reduced signi-ficantly from 73 ± 3.6 to 24.75 ± 7.25% in rat aortic rings (p < 0.05). Ach relaxations were significantly enhanced (p < 0.05) at 5-minute exposure; however at longer durations, Ach-relaxations were variable and inconsistent. The lesser the dilution, due to increased volume of parasitized blood, the lesser the relaxation response. Following endothelium removal, there was a marked impairment in endothelium-dependent relaxation responses to ACh in both the control and incubated vessels. Exposure to para-sitized blood did not significantly alter contractile responses induced by potassium depolarization. Conclusions: This gives evidence in support of an endothelium-dependent action of malaria parasites as vascular effects of malaria parasites are mediated, at least in part, via endothelium-dependent mechanism(s). Keywords: Malaria, vascular, reactivity, tissue specificity Reactividad Vascular Alterada Inducida por los Parásitos de la Malaria RESUMEN Objetivo: En este estudio, hemos examinado la posibilidad de que exista una reactividad vascular alterada debido a la interacción directa entre los eritrocitos parasitados y las células endoteliales vasculares. Método: Se estudiaron preparaciones de anillo de aorta de rata usando técnicas in vitro estándar. Los anillos fueron montados en baños de órgano de 20 ml que contenían solución salina fisiológica (SSF) con una carga inicial de 1g, mantenida a 37°C con un pH de 7.4, y las contracciones isométricas fueron registradas electrónicamente. A los anillos se les dio un tiempo de 90 minutos para permitir que se equilibraran, antes del comienzo de los varios protocolos. *Respuestas a la dosis de fenilefrina (FE) y otros agentes vasoactivos (K+ alto) *Relajación inducida mediante acetilcolina (Ac) en los anillos contraídos con fenilefrina (la pre-contracción fue inducida mediante una concentración EC70 de fenilefrina) *Relajación inducida mediante Ac en anillos despojados de endotelio. Pre-contraídos con FE. *También, se investigaron las respuestas de relajación a la acetilcolina a través de la aplicación de una sola concentración (EC70) de acetilcolina en anillos expuestos a la sangre con diversas concentraciones y diluciones de sangre parasitada y distintas duraciones de exposición. Resultados: La incubación con sangre parasitada tuvo como resultado un aumento significativo en la respuesta contráctil máxima a la fenilefrina en los anillos aórticos de las ratas (p < 0.05) pero ningún efecto a la línea de base. El análisis de toda la curva de respuesta a la dosis (usando la prueba t pareada) mostró un desplazamiento significativo hacia la izquierda tras la adición de sangre parasitada (p < 0.05), EC70 (M), aumentado los valores de 7 x 10-7 a 5 x 10-6 M. Tras la exposición a la sangre parasitada, la magnitud de las respuestas a la relajación inducida por Ac se redujo significativamente de 73 ± 3.6 a 24.75 ± 7.25% en los anillos aórticos de ratas (p < 0.05). Las relajaciones por Ac mejoraron significativamente (p < 0.05) a los 5 minutos de exposición. Sin embargo, a duraciones más largas, las relajaciones por Ac fueron variables e inconstantes. Mientras menor era la dilución, debido al aumento de volumen de la sangre parasitada, menor era la respuesta de relajación. Una vez retirado el endotelio, se producía un marcado deterioro en las respuestas de relajación dependiente del endotelio, ante el Ac, tanto en los recipientes de control como en los encubados. La exposición a la sangre parasitada no alteró de manera significativa las respuestas contráctiles inducidas por la despolarización del potasio. Conclusiones: Esto provee evidencias en apoyo a una acción dependiente del epitelio, por parte de los parásitos de la malaria, por cuanto los efectos vasculares de los parásitos de la malaria se hallan mediados, al menos en parte, por los mecanismos dependientes del endotelio. Palabras claves: Malaria, vascular, reactividad, especificidad del tejid

Estimation of absorbed cadmium in tissues of male and female albino rats through different routes of administration

The resultant effects of cadmium exposure are seen in almost all the systems of the body, however, this study is designed to quantify its accumulation in tissues of animals exposed to cadmium. The rats were divided into two distinct groups of males and females, which were then divided into three groups, each for the monitoring of exposure. Group 1 served as control male and female and received normal rat chow and tap water. Group 2 males and females were treated with 5 mg/kg body weight of cadmium chloride (Cd) intraperitoneally for eight days while Group 3 males and females rats received 100 ppm of Cd in drinking water for 18 days. The concentrations of cadmium were analyzed in tissues (lung, stomach, kidney, heart, spleen, blood) by AAS. There were significant (P&lt;0.05) increase in Cd (ppm) accumulation in males compared with females lungs (2.253 ± 1.47 vs 0.317 ± 0.001), stomach (0.187 ± 0.094 vs 0.045 ± 0.032) and blood (0.070 ± 0.001 vs 0.001±0.001) when Cd was administered intraperitoneally. Following oral administration, there were significant (P&lt;0.05) difference in Cd (ppm) content between males and females (kidney (0.506 ± 0.074 vs 0.748 ± 0.147), stomach (0.045 ± 0.020 vs 0.001±0.001) and blood (1.126 ± 0.001 vs 0.114 ±0.001). Our results suggest that Cd accumulation in the various organs was sex and route of exposure-dependent in rats. Keywords: Cadmium, Heavy metals, Organs, Route of administration, Sex Nig. J. Physiol. Sci. 26(June 2011) 097 – 10

Specificity of Vascular Reactivity and Altered Response in Experimental Malaria

Objective: Adherence of erythrocytes infected with Plasmodium falciparum (P falciparum) to microvascular endothelial cells (sequestration) is considered to play an important role in parasite virulence and pathogenesis. In this study, we have examined the possibility that there is altered vascular reactivity due to the direct interaction between the parasitized erythrocytes and vascular endothelial cells and that it could be tissue specific. Method: Ring preparations of blood vessels from the rabbit carotid and rat aorta were studied using standard organ bath techniques. Dose response curves for phenylephrine (PE) and acetylcholine (Ach)-induced relaxation were constructed in rings pre-contracted with PE. Results: Incubation of rat aortic rings with parasitized blood resulted in a significant (p < 0.05) increase in maximum contractile response to phenylephrine in the rat aortic rings but there was no effect on the rabbit carotid artery. The dose-response curve showed a significant (p < 0.05) left-ward shift following the addition of parasitized blood. Parasitised blood had no effect on baseline in both tissues. Following exposure to parasitized blood, the magnitude of Ach-induced relaxation responses reduced significantly (p < 0.05) in rat aortic rings and (p < 0.05) in rabbit carotid rings; relaxations to acetylcholine was more pronounced in the aortic compared to the carotid rings. Conclusions: Malaria altered vascular reactivity through an endothelium-dependent mechanism. The regulation of vascular tone by various vasoactive agents following exposure to malaria parasites might be altered in a vessel-specific manner. This may contribute to or exacerbate the abnormal haemodynamics observed in the microcirculation of numerous vascular beds in malaria. Keywords: Malaria, vascular reactivity, vessel specificity "Especificidad de la Reactividad Vascular y Respuesta Alterada en la Malaria Experimental" RESUMEN Objetivo: Se considera que la adhesión de eritrocitos infectados con Plasmodium falciparum (P falciparum) a las células endoteliales microvasculares (secuestración) juega un papel importante en la virulencia parasitaria y la patogénesis. Este estudio examina la posibilidad de que se produzca reactividad vascular alterada debido a la interacción directa entre los eritrocitos parasitados y las células endoteliales vasculares, y que la misma se deba al tejido específico. Método: Preparaciones de anillos de vasos sanguíneos de carótida de conejo y aorta de rata, se estudiaron usando técnicas de baño de órgano normales. Las curvas dosis-respuesta de fenilefrina (PE) y relajación inducida por acetilcolina (Ach) fueron construidas en anillos pre-contraídos con PE. Resultados: La incubación de anillos aórticos de rata con sangre parasitada trajo un aumento significativo (p < 0.05) de la respuesta contráctil máxima a la fenilefrina en los anillos aórticos de rata, pero no hubo efecto sobre la arteria carótida de conejo. La curva dosis-respuesta mostró un cambio significativo (p < 0.05) hacia la izquierda luego de que se añadiera sangre parasitada. La sangre parasitada no tuvo efecto en ninguno de los dos tejidos con respecto a los valores iniciales (línea de base). Luego de ser expuesta a la sangre parasitada, la magnitud de las respuestas de relajación inducida por acetilcolina, se redujo significativamente (p < 0.05) en los anillos aórticos de rata, y (p < 0.05) en los anillos de carótida de conejo. Las relajaciones con respecto a la acetilcolina fueron más pronunciadas en los anillos aórticos en comparación con los anillos de carótida. Conclusiones: La malaria alteró la reactividad vascular a través de un mecanismo dependiente del endotelio. La regulación del tono vascular por los varios agentes vasoactivos tras la exposición a los parásitos de la malaria, podría ser alterada de manera vaso-específica. Esto puede contribuir o exacerbar la hemodinámica anormal observada en la microcirculación de numerosos lechos vasculares en la malaria. Palabras claves: malaria, reactividad vascular, especificidad vascula

Prolactin secretory response during academic exercises in young adult male students

No Abstract.Journal of Biomedical Investigation Vol. 5 (2) 2007 pp. 63-6

Serum Lipids, Proteins and Electrolyte Profiles in Rats Following Total Body Irradiation

Objective: Serum lipid and electrolyte imbalances are common in critically ill patients undergoing radiation therapy. Although multiple disease states and medication may be responsible for the development of these disorders, the aim of this research is to sequentially document the effect of total body radiation on body function utilizing the sequential changes in the serum lipids, electrolytes and protein in rats. Methods: Serum protein and lipids contents were assessed using kits while electrolytes were assessed with flame photometry in rats exposed to total body irradiations of 1.27 Gy/min in cumulative doses to the fourth irradiation at five-day intervals. Results: Total cholesterol and triacylglycerols serum levels were significantly reduced by irradiation (p < 0.05). No significant differences between experimental and control groups for HDL-C serum levels were detected. Serum electrolyte concentration remained within the normal range after each total body irradiation. Sodium, bicarbonate and chloride were significantly (p < 0.05) higher than control while potassium and creatinine were significantly reduced after the first irradiation only. Sodium/potassium ratio was significantly (p < 0.05) elevated. Serum protein was significantly (p < 0.05) elevated with increasing radiation. Conclusion: There are subtle but significant changes in serum lipids, electrolytes and protein after total body irradiation of normal rats. These variations could be due to non-specific stress reactions; as such, they are important markers in radiation induced injury diagnosis. Keywords: Lipid profile, protein, radiation injury, serum electrolytes "Perfiles de Lípidos, Proteínas y Electrolitos Plasmáticos en Ratas tras Irradiación Corporal Total" RESUMEN Objetivo: Los desequilibrios de lípido y electrolito plasmáticos son comunes en los pacientes críticos sometidos a terapia radioactiva. Aunque los múltiples estados de la enfermedad y la medicación pueden ser responsables del surgimiento de estos trastornos, el objetivo de esta investigación es documentar de manera secuencial el efecto de la radiación corporal total sobre la función corporal, utilizando los cambios secuenciales en los lípidos, electrolitos y proteínas plasmáticos en las ratas. Métodos: Los contenidos de lípidos y proteínas plasmáticos fueron evaluados utilizando kits, en tanto que los electrolitos fueron evaluados mediante fotometría de llama en ratas expuestas a irradiaciones corporales totales de rayos X de 1.27 Gy/min, en dosis cumulativas hasta la cuarta irradiación en intervalos de cinco días. Resultados: El colesterol total y los niveles plasmáticos de triacilgliceroles fueron reducidos signi-ficativamente por la irradiación (p < 0.05). No se detectaron diferencias significativas entre; os grupos experimentales y de control en relación con los niveles plasmáticos de colesterol HDL. La concen-tración de electrolito plasmático se mantuvo dentro de los límites normales luego de cada irradiación corporal total de rayos X. La relación sodio/potasio fue significativamente elevada (p < 0.05). La proteína plasmática se elevaba significativamente (p < 0.05) al aumentar la radiación. Conclusión: Tras la irradiación corporal total de las ratas normales, se producen cambios sutiles pero significativos en los lípidos, electrolitos y proteínas del plasma. Estas variaciones podrían ser debidas a reacciones de estrés no específicas, y como tal, son marcadores importantes en el diagnóstico de las lesiones inducidas por la radiación. Palabras claves: Perfil lípido, proteína, lesión por radiación, electrolitos plasmático