RESUMO
A brief commentary of the genetics of blood pressure is presented. The importance of the mechanisms of blood pressure regulation, among which heart rate is relevant, is emphasized. The analysis of a small population to test the quantitative model of the trait heart rate, considered as a metric character, is presented. The analysis of heart rate fitting to a qualitative model of inheritance is carried out. The results displayed might support the hypothesis that tachycardia could be an autosomal, monogenic, biallelic recessive trait.
Assuntos
Pressão Sanguínea/genética , Frequência Cardíaca/genética , Taquicardia/genética , Alelos , Genes Recessivos , Humanos , Modelos Cardiovasculares , Modelos Genéticos , Característica Quantitativa HerdávelRESUMO
OBJECTIVES: To analyze the influence of weight and different body mass indexes on blood pressure (BP) values. The study was carried out in 823 volunteers (345 males, 478 females), aged 25/80 years. A standardized protocol, based on the recommendations provided by the V Joint National Committee was set up. The means of three consecutive readings taken at 2-min. intervals on three occasions were used. Weight and height were determined and the indexes were calculated. Correlations between weight and the selected indexes, with SBP and DBP, respectively, by sex and age interval were performed. The most representative indexes were body mass index (BMI) followed by lean BMI and weight. Analysis of BP values are BMI, for a period starting at 25 years and ending at 74 year, for both SPB and DBP, in comparison with the Humboldt Study data was performed, showing a strikingly similar pattern of behavior with our data. Additionally, weight and BMI are more closely associated with DBP in males than in females. Conversely, this association is closer in women with SBP. The importance of the ethnic factor is emphasized in order to establish body mass index cut-off values regarding the population under study, because the values proposed by the American Heart Association are probably rather high for our population.
Assuntos
Pressão Sanguínea , Índice de Massa Corporal , Peso Corporal , Adulto , Idoso , Argentina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , População Urbana/estatística & dados numéricosRESUMO
Lerner's concept of developmental homeostasis, formerly elaborated with regard to the study of morphological traits, is proposed as a way of analysing the heritability of blood pressure. The important and controversial contribution of the autonomic nervous system to blood pressure regulation is also discussed with the aid of the hyperkinetic state, an entity described by Julius and Schork, and considered as an etiological factor in the occurrence of borderline hypertension. Experimental support through an analysis of a study performed on 87 pedigrees of normal healthy individuals is provided. The analysis calculates the heritabilities of systolic and diastolic blood pressure as well as heart rate. A classification in four categories, taking into account the hyperkinetic state, using the combined values of heart rate and mean arterial blood pressure is proposed, and its value regarding the categorization of normal individuals is emphasized and discussed simultaneously with the heritabilities calculated, in an attempt to explain the contribution of Lerner's theory to the inheritance of blood pressure.
Assuntos
Pressão Sanguínea/genética , Homeostase , Adulto , Feminino , Frequência Cardíaca , Humanos , Hipertensão/etiologia , Hipertensão/genética , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Núcleo Familiar , Linhagem , Valores de ReferênciaRESUMO
Administration of 1,25-dihydroxycholecalciferol (0.5 microgram/d/100 g body weight) to vitamin D repleted rats produced a significant decrease in the number of femoral marrow cells, specially in the erythroid line. Analysis of blood revealed slight anemia with reticulocytopenia. The survival time of 51-Cr-labelled red cells was unaffected by treatment, suggesting that bone marrow became unable to replace cells at a normal rate. The adverse effect on erythropoiesis appeared related to the degree of the concurrent hypercalcemia, which in turn depends upon the calcium content of the diet.
Assuntos
Calcitriol/farmacologia , Cálcio/metabolismo , Eritropoese/efeitos dos fármacos , Reticulócitos/análise , Anemia/induzido quimicamente , Animais , Células da Medula Óssea , Calcitriol/administração & dosagem , Dieta , Ratos , Ratos EndogâmicosRESUMO
Administration of 1,25-dihydroxycholecalciferol (0.5 microgram/d/100 g body weight) to vitamin D repleted rats produced a significant decrease in the number of femoral marrow cells, specially in the erythroid line. Analysis of blood revealed slight anemia with reticulocytopenia. The survival time of 51-Cr-labelled red cells was unaffected by treatment, suggesting that bone marrow became unable to replace cells at a normal rate. The adverse effect on erythropoiesis appeared related to the degree of the concurrent hypercalcemia, which in turn depends upon the calcium content of the diet.