Ageing and circadian rhythm of plasma renin and aldosterone.

Five men and 8 women, 60-69 yr of age, and 4 men and 5 women, 17-37 yr of age, volunteered for this exploration of possible age-related changes in circadian-rhythm (CR) characteristics of radioimmunoassayable plasma renin (PRA) and aldosterone (PA). Blood was drawn at 06.00, 08.00, 12.00, 18.00, 20.00 and 24.00 from recumbent subjects on a habitual sodium intake of 120-140 mEq/24 h. Time-qualified data of PRA and PA, fitted by a 24-h cosine curve, were summarized by a population mean-cosinor method. Circadian characteristics were compared by a multivariate analysis using Hotelling's t2 test. Rhythmometry reveals in the elderly women a lower mesor (P less than 0.001) and amplitude (P = 0.036) of the CR in PRA and a higher mesor and amplitude (P = 0.021 and P = 0.020, respectively) of the PA-CR. The PRA acrophase is delayed (P less than 0.001) in the elderly women (04.40 vs. 08.04) while the timing of the PA acrophase is similar in the age groups of women compared (05.52 vs. 05.20). These differences found in women were not observed in the smaller groups of men. The seventh decade of life may be characterized by an internal circadian desynchronization between the major components of the renin-angiotensin-aldosterone system. A sex-dependent amplification of the extent of circadian variation in aldosterone may precede a decrease in the circadian amplitude occurring during the eighth decade of life, as a sign of the adrenopause in women.

[Primary dilated cardiomyopathy]. / Cardiomiopatia dilatativa primitiva.

Recent advances in etiopathogenesis and natural history of idiopathic dilated cardiomyopathy are presented. The clinical and instrumental diagnosis and therapy are also reported.

[Behavior of plasma cortisol in the course of testing with lysine-8-vasopressin and with lysine-8-vasopressin + resperine in normal subjects]. / Comportamento del cortisolo plasmatico nel corso della prova con lisin-8-vasopressina e con lisin-8-vasopressina+reserpina, nel soggetto normale.

Eight normal subjects were tested with LVP before and after treatment with Reserpine. The results show that Reserpine inhibits the cortisolemic response to the LVP test. This effect can most likely be attributed to the depletion of catecholamines induced by these drugs on the CNS and, in particular, in the Hypothalamus.

[Influence of haloperidol on blood cortisol response to lysine-8-vasopressin in normal subjects]. / Influenza dello aloperidolo sulla risposta cortisolemica alla lisin-8-vasopressina, nel soggetto normale.

The investigations were done on ten normal subjects. The LVP test was performed before and after intravenous-infusion of Haloperidol (Img). The results show that haloperidol eliminates the cortisolemic response during stimulation with LVP; that is most likely, in relation to the specific blocking effect of this drug on dopaminergic receptors in the hypothalamus and on the hypothalamo-diencephalic pathways.

[Behavior of plasma cortisol during testing with insulin and with LVP in obese subjects compared to normal subjects after resperine administration]. / Comportamento del cortisolo plasmatico nel corso delle prove con insulina e con LVP nel soggetto con eccedenza ponderale rispetto al soggetto normale dopo somministrazione di reserpina.

The behaviour of plasma cortisol levels was studied in fifteen overweight subjects with comparison to normal subjects. In eight subjects the insulin hypoglycemic test was performed before and after medication with reserpine (4mg/24HR); the other seven subjects were tested with LVP before and after treatment with reserpine. In both cases, premedication with reserpine significantly reduce the cortisolemic response. This behaviour is similar to the response observed in normal subjects.