[The correlation of atrial natriuretic peptide values with those of renin, angiotensin and aldosterone in hypertension patients below and above 50]. / Correlación de valores de péptido natriurético auricular con los de renina, angiotensina y aldosterona en pacientes hipertensos menores y mayores de 50 años.

A comparison of ANP and RAA. In 6 healthy subjects < 50 y, 5 healthy subjects > 50 y, 44 patients with essential hypertension < 50 y, and 41 patients with essential hypertension > 50 y, was performed. ANP values in healthy subjects < 50 y, were means = 44 +/- 7 PG/ml, and means = 87.33 +/- 14 PG/ml in those > 50 y. (P < 0.01). 80% of hypertensives < 50 y, had normal values of ANP (means = 63.8 +/- 10 PG/ml) and 20% high values (means = 131 +/- 6 PG/ml) (P < 0.001). 70% of hypertensives > 50 y, had high ANP values (means = 260 +/- 114 PG/ml) and 30% normal values (means = 75 +/- 5 PG/ml) (P < 0.001). Values for RAA were low or normal in 96% of cases with high ANP values (P < 0.001), and 100% of the cases with high RAA values, had low or normal ANP values. (P < 0.0001). This correlation had an statistically significant value for groups over 50 years (high ANP values, low RAA values) (P < 0.001) and high RAA values with low or normal ANP values in groups below 50 y (P < 0.001). We observed no significant correlation between ANP values and LVH. According to our results, essential hypertensives < 50 y, have low or normal ANP values in the majority of cases (P < 0.001). Essential hypertensives over 50 y. Have high ANP values also in the majority of cases (P < 0.001). As previously reported, an inversely proportional ratio between RAA and ANP was found in our study. The significance of ANP in regulating blood pressure in the elderly is considered.

Human pituitary hormones extraction.

In order to know the efficiency of the human pituitary hormone extraction method utilized in the laboratory, six batches of 100 pituitaries each, were collected in acetone. Its delipidization and the initial acid extraction (0.3 M KCl, pH 5.5) of the powder were performed in the presence of 0.1 per cent thioethanol and the extraction was completed with an alkaline solution (0.1 N NaOH + H2O, v/v, pH 10.5). Hields in weight of powder and protein concentration for each fraction were similar to those previously reported by Elrick. Characterization of fractions with disc-gel-electrophoresis demonstrated a reproducible pattern for GH, and some differences among the samples containing the glycoproteins. The hormonal activities determined by radioimmunoassay showed a low contamination of GH in the fractions rich in glycoproteins, but these latter were similarly distributed between the acid and the alkaline extracts. The glycoprotein fraction had an important activity of TSH. The hormonal content per pituitary was calculated from the addition of activities in both extracts and the last residue; GH = 3 mg (4.494 IU); FSH = 761 micrograms (13.410 IU); LH = 782 micrograms (46.920 IU); TSH = 2.939 mg (9.350 IU). It is concluded that the technique is useful since there was a low GH contamination in the glycoprotein fraction and the TSH yield was important.