In this study, myocardial E', A' and S' velocities, in both the left and the right ventricle, were significantly affected by preload in healthy subjects. Our results support the usefulness of the E'/A' ratio as a relatively load-independent index of diastolic function.

The cytoplasmic free calcium concentration [( Ca2+]i) was assessed with the fluorescent dye Quin 2 in platelets and lymphocytes of spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto rats (WKY), essential hypertensive patients (EHP) and normotensive human control subjects (NCS). [Ca2+]i was significantly higher in the platelets of 8- and 20-week-old SHR in comparison with WKY. However, no difference was evident after weaning. Changes of cellular calcium in hypertensive rats apparently evolved simultaneously with the development of high arterial pressure. [Ca2+]i was significantly higher in platelets of EHP than in NCS. In lymphocytes of SHR, [Ca2+]i was not different from WKY at 4 and 8 weeks, but was increased at 14 weeks and at older ages. In EHP, intralymphocytic [Ca2+] was only modestly higher than in controls. On the whole, the results suggest that control of cytoplasmic calcium in these blood cells is similarly affected in human and animal models of primary hypertension.

In order to investigate the renal function, a cross-sectional study was carried out on four groups of workers significantly exposed to a mixture of alicyclic and aliphatic C5-C7 hydrocarbons, to styrene, to a mixture mostly composed of toluene and xylenes and to chlorinated hydrocarbons, respectively. The study involved 438 workers. Exposure was characterized by means of urinary metabolites, or by means of environmental measures, when biological indicators were not available. The renal function impairment indicators included total proteinuria, albuminuria and urinary excretion of muramidase (E.C. 3.2.1.17) and beta-glucuronidase (E.C. 3.2.1.31). The trend of these parameters provides some evidence of renal damage due to occupational exposure to organic solvents and suggests that the lesions are mild and tubular rather than glomerular.

Abstract-The activation of the sympathetic nervous system is a common feature of arterial hypertension and other cardiovascular diseases. This activation might be dependent on an altered baroreflex control of vascular resistance of which the inhibitory response on sympathetic activity appears impaired. The aim of the study was to monitor during the natural course of arterial hypertension in spontaneously hypertensive (SHR) and age-matched Wistar Kyoto (WKY) rats (5, 16, 30, and 54 weeks of age) the peripheral sympathetic activity expressed as interstitial norepinephrine (NE) release and as tyrosine hydroxylase (TH) activity, the rate-limiting enzyme of NE synthesis, in the differently baroreflexcontrolled subcutaneous adipose tissues and skeletal muscles. Blood pressure and plasma NE in SHR were similar to WKY at 5 weeks of age but increased at all other ages. Body weight was similar in both 5-week-old rats but reduced in SHR at all other ages. The interstitial NE levels were greater in both SHR tissues at all ages as compared with WKY. In adipose tissue of SHR, TH activity was higher at all ages as compared with WKY, whereas TH activity in skeletal muscle was higher only after the development of hypertension. These data show that in both SHR tissues, an increase of interstitial NE release is always present during its lifespan. This suggests that increased sympathetic activation in the SHR model is not specific to baroreflex-controlled tissues such as skeletal muscle but involves also subcutaneous adipose tissue, the sympathetic efferents of which are independent from baroreflexes.

The presence of impaired relaxation was confirmed by DTE in a large portion of patients with hypertension and left ventricular hypertrophy. A peculiar systolic disturbance is evidenced by this technique. DTE-derived information can be used to detect early and quantify target-organ damage and its progression or regression during antihypertensive treatment.