Meta-analysis about Atrial Natriuretic Peptide (ANP)

Among the topics studied in physiology and aging, a hormone has been drawing attention from the scientificcommunity: the Atrial Natriuretic Peptide (ANP). The ANP, which is produced by the cardiac atria, hasdemonstrated decisive action in endocrine mechanisms of action inhibiting sodium reabsorption in nephrons,revealing a direct influence on physiological mechanisms linked to aging and chronic stress.The overall objectiveof this study was to assess and analyze scientific literature on the ANP in the Pubmed database from 2010 to2012. 30 articles were collected, verifying authorship and gender division of species, instruments and typesof research. The results showed that the research of multiple authorship appeared mostly with 99.1%, being51.8% of male authorship, 17.9% of female authorship and 29.5% of publications not identified. Researchwith only one author appears with 0.8% in total. As the types of species used, it was observed 50.3% of theworks with humans, 40% with animals and 6.7% mixed (animal / human). As to the instruments used, thebiochemical markers were the ones that stood out, with 30%, followed by label arterial pressure with 12, 2%,drugs, with 11.1% and microscopic studies with 10%. In the typology of research, biochemical research appearsfirst, with 33.3%, followed by research morphophysiological/biochemical research, with 30%, Physiological/ biochemical, with 26.7%, Physiological with 6.7% and Morphophysiological with 3.3%. We can concludethat the publications about the hormone ANP are still little explored when the focus is aging. In the analyzedpublications, there is important information about the physiological and biochemical role of ANP as well ason their molecular composition.

Effects of protein deprivation and refeeding on the subepicardial neurons of rat: subepicardial neurons and low-protein diet

Heart autonomic ganglia play an important role in cardiac rhythm control, protecting against certainarrhythmias due to their parasympathetic activity. Starvation during pregnancy may cause cardiac disorders andhinder optimal cardiac performance. Also, morphology of subepicardial neuron is subjected to the influenceof extrinsic factors. We studied the influence of protein deprivation on subepicardic neurons in rats at earlydevelopment stages and the effect of restoration of a normal diet.: Three groups of pregnant Wistar rats weresubmitted to different diets according to its protein content: normal (NN group) and 5% casein (DD group),until 42 days after delivery and low protein for 21 days with refeeding for a further 21 days (RN group).All animal were weighed. The number and area of neuronal profiles were measured. The neurons werestained by histochemical methods â-nicotinamide adenine dinucleotide (NADH) and â-nicotinamide adeninedinucleotide phosphate diaphorase (NADPH-d) and their ultra structure were observed.Group DD and RNanimals weighed less than those from group NN. The number of neurons and the cellular profile area didnot show significant differences among groups for both techniques. Endoplasmatic reticulum ribosomes inneurons of undernourished animals showed decreased electron density. Protein deprivation in early stages ofdevelopment produces ultra structural changes but does not alter the number and profile area of nerve cellbodies in rats.

Dietary sodium intake induced myenteric neuron hypertrophy in Wistar rats

In the present study we investigated the effect of salt intake on myenteric neuron size of the colon of adult male Wistar rats. The animals were placed on either a high-salt (HS; 8 percent; 12 animals) or a low-salt diet (LS; 0.15 percent; 12 animals) for 15 or 52 weeks and blood pressure was measured. The sizes of myenteric neurons of the distal colon from both groups were measured. No difference in neuron size was observed between the HS and LS groups after 15 weeks. After 52 weeks on HS, neuron size was increased (P<0.005) when compared with the LS group. The rats also presented hypertension, which was significantly different at 52 weeks (142 +/- 11 vs 119 +/- 7 mmHg). These results suggest that a long time on an HS diet can significantly increase myenteric nerve cell size.