Effects of an aqueous extract of Terminalia arjuna on isolated rat atria and thoracic aorta

Terminalia arjuna (Combretaceae) is used traditionally in ayurveda, to treat a variety of cardiovascular disorders. The aims of this study were to characterize the positive inotropic effect of the aqueous extract of T. arjuna bark in isolated paced rat left atria and to study its effects on a vascular smooth muscle preparation, the rat thoracic aorta. The crude and semipurified aqueous extracts produced a positive inotropic effect of rat atria and the maximum contraction was comparable to that produced by isoprenaline. The positive inotropic effect of the extract was completely blocked by a β-adrenoceptor blocker, propranolol, and an uptake-1 blocker, cocaine. In precontracted aorta, the aqueous extract produced a contraction followed by relaxation. Propranolol did not block the relaxant effect of the aqueous extract. It is concluded that the positive inotropic effect of the aqueous extract was mediated via an action on β₁-adrenoceptors and was likely to be due to the release of noradrenaline from the sympathetic nerve endings. The vasorelaxant effect of the extract, however, was not mediated via an action on β₂ adrenoceptor.     

Accumulation of nitrotyrosine correlates with endothelial NO synthase in pulmonary resistance arteries during chronic hypoxia in the rat

Nitrotyrosine and eNOS were detected immunocytochemically using specific antibodies in paraffin sections of lung from rats subjected to hypoxia for 2, 7, or 14 days. The staining intensity for eNOS was enhanced in the endothelium of both resistance and conduit pulmonary arteries at 2 days. Staining intensity for eNOS remained elevated at 7 and 14 days in conduit arteries, whereas it progressively increased further in resistance arteries. Nitrotyrosine staining was elevated to a similar degree in endothelium and adjacent vascular smooth muscle. In resistance pulmonary arteries, there was a progressive increase in nitrotyrosine, which matched the increase in eNOS. In conduit pulmonary arteries, nitrotyrosine increased only after 14 days of hypoxia. The results suggest that in chronic hypoxia the up-regulation of eNOS leads to the formation of peroxynitrite which has access to both endothelium and vascular smooth muscle.     

Diet and nutritional status of adolescent tribal population in nine states of India

Tribal population constitutes about 8% of the total population in India. They are particularly vulnerable to undernutrition, because of their geographical isolation, socio-economic disadvantage and inadequate health facilities. Recognizing the problem, Government of India launched different programmes for their welfare. Adolescence is a significant period of growth and maturation. The nutritional status of adolescent girls, the future mothers, contributes significantly to the nutritional status of the community. Therefore an attempt was made to assess the diet and nutritional status of adolescent population from the different tribal areas of India. The available database collected by National Nutrition Monitoring Bureau (1998-99) was utilized for this purpose. Data on a total of 12,789 adolescents (10-17 yrs) was included for the analysis. Four percent of the adolescent girls were married and less than 1% were either pregnant (0.4%) or lactating (0.7%) at the time of the survey. The mean intake of all the foodstuffs, especially the income elastic foods such as Pulses, Milk & Milk products, Oils & fats and Sugar & Jaggery were lower than the recommended levels of ICMR. The intake of all the foodstuffs except green leafy vegetables was lower than that of their rural counterparts. The intake of all the nutrients were below the recommended level, while that of micronutrients such as iron, vitamin A and riboflavin were grossly inadequate in all the age and sex groups. About 63% of adolescent boys and 42% of girls were undernourished (< 5th BMI age percentiles of NHANES). A significant association between undernutrition and socio-economic parameters like type of family, size of land holding and occupation of head of household was observed. Therefore, there is a need to evolve comprehensive programmes for the overall development of tribal population with special focus on adolescents.     

Diet and nutritional status of rural preschool children in Punjab

OBJECTIVE: To assess diet and nutritional profile of rural preschool children of Punjab. STUDY DESIGN: Multistage random sampling method was adopted by following probability proportion to population size (PPS). SUBJECT: Four hundred households (HH) were covered in each district of Punjab for socio-economic and demographic information. All the available individuals from these HHs were included for anthropometry and clinical examination. Every fourth household was covered for 24-hour recall method of diet survey (individual dietary intake). RESULTS: At the state level, the intake of macro and micronutrient rich foods such as cereals, pulses and green leafy vegetables, milk and milk products and fats and oils were lower than the RDI among preschool children. Except for protein, calcium and thiamine, the mean intake of all the nutrients was lower than the recommended level. About a half of the preschool children (50.3%) were undernourished (> 2SD weight for age); 60% were stunted (> 2SD height for age) and 12% were wasted (> 2SD weight for height). The extent of undernutrition and stunting was lower than that reported for the country. There was significant variation in the prevalence of severe stunting between the districts (p < 0.001), with the highest being observed in the Rupnagar (55%) and the lowest in Hoshiarpur and Sangrur (30% each). CONCLUSION: Despite, the reported high rates of economic growth and food production in the state, a higher proportion of preschool children were consuming diets, which are inadequate with respect to energy, fat, iron, riboflavin, vitamin A and vitamin C. The prevalence of undernutrition was high as was found in other states.     

Phytoestrogens restore nitric oxide-mediated relaxation in isolated pulmonary arteries from chronically hypoxic rats

Phytoestrogens derived from soybeans reverse endothelial dysfunction in a number of animal models of systemic vascular disease. Based on these studies, we hypothesized that phytoestrogens would reverse chronic hypoxia-induced endothelial dysfunction in rat pulmonary arteries. To test this hypothesis we examined the effect of genistein, the major phytoestrogen found in soybeans, on carbachol-induced relaxation in phenylephrine-constricted pulmonary artery rings isolated from normoxic rats and rats exposed to 14 days of hypobaric hypoxia. Compared with that in normoxic rats, the response to carbachol was impaired in pulmonary arteries isolated from rats exposed to chronic hypoxia. In normoxic rat pulmonary arteries, genistein (30 microM) did not change the maximum relaxation to carbachol. In contrast, genistein significantly enhanced the relaxation response to carbachol in pulmonary arteries from hypoxic rats, restoring it to the levels seen in normoxic rats. 17beta-estradiol (10 microM) and daidzein (30 microM), a structural analog of genistein lacking inhibitory effects on tyrosine kinases, also restored the relaxation response to carbachol in hypoxic rat pulmonary arteries. The nitric-oxide synthase inhibitor N(omega)-nitro-L-arginine (100 microM) completely blocked the genistein, daidzein, and 17beta-estradiol-induced restoration of the relaxation response to carbachol, whereas the estrogen receptor antagonist ICI 182,780 (10 microM) had no effect on the relaxation responses. We conclude that the phytoestrogens genistein and daidzein act like estrogen in restoring nitric oxide-mediated relaxation in chronically hypoxic rat pulmonary arteries and that this effect does not appear to be mediated by inhibition of tyrosine kinases or by known estrogen receptors.     

Effect of K+ channel blocking drugs and nitric oxide synthase inhibition on the response to hypoxia in rat pulmonary artery rings

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