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To evaluate the correlations occurring among plasma atrial natriuretic factor (ANF), renin activity (PRA), aldosterone (ALD) and urinary kallikrein (KK) in young hypertensives and in young normotensives with or without a family history of hypertension, 26 essential hypertensives (mean age: 22.5 +/- 2), 21 normotensives (mean age: 22.3 +/- 1.9) and 13 normotensives with hypertensive heredity (mean age 22 +/- 1.8) under normal Na+ intake (120 mEq/daily) were studied. Blood samples for plasma ANF, PRA and ALD evaluations were taken after a night bed sleep (A) and again after 1 hour of deambulation (B). KK was evaluated on 24 hours urine specimens by the chromogenic substrate (S-2266) method. The results showed that ANF plasma levels in hypertensives (A = 44.5 +/- 19.4 pg/ml, B = 24.1 +/- 11 pg/ml) were higher than in normotensives (A = 38.3 +/- 19.4 pg/ml, B = 19.9 +/- 10.6 pg/ml), with a percentage difference of 13.8% in A situation and 17.4% in B situation. Moreover ANF was higher in normotensives with hypertensive heredity than in normotensives without heredity (A = +7.4%; B = +10%). In B situation ANF was inversely correlated with ALD in all groups (p less than 0.001 in hypertensives; p less than 0.05 in both groups of normotensives), and with PRA in hypertensive group (p less than 0.001). KK was significantly lower in hypertensives than in normals (p less than 0.01) showing only in hypertensive patients an inverse correlation with ANF (r = -0.60; p less than 0.001). In conclusion, our data indicate that raised levels of plasma ANF may be present in young hypertensives with low levels of PRA, ALD and KK.

Mortality due to respiratory diseases has been stable in Italy during this century, but this stability seems to be artificial due to TBC and pneumonias mortality decrease and chronic obstructive pulmonary disease (COPD) and cancer mortalities increase. In 1977 COPD morbidity caused 3,000,000 off-days, but these old data probably underestimated the real situation: indeed the greatest mortality is registered, as it is well know, in the elderly subjects (greater than 75 years), and this age was not considered in these data. More recently, a finalized project has been established by the National Research Council (CNR) to obviate poorness of data on COPD epidemiology with particular regard to its morbidity. At the present time, data have not yet been published. COPD appears to affect males more than females, while race does not seem important in COPD distribution. Moreover, a marked increase in respiratory dysfunction is observed with age. Alpha-1-antitrypsin deficit plays a significant role in COPD pathogenesis, while the influence of surface cells antigens and secretory state is still unclear. COPD is more frequent in some families than in general population, as well as in monozygote twins than in dizygote ones. However, the influence of genetically determined predisposition could be overestimated, being COPD frequencies in these cases linked to other risk factors. According to the "Dutch hypothesis" bronchial hyperreactivity is an indispensable condition in COPD pathogenesis, while "British hypothesis" gives more importance to recurrent bronchial inflammation. Some contaminants play an important role in COPD pathogenesis, both in urban (NO2, NO3, SO3) and working environments (coke, etc.). Smoke is the last factor considered in the pathogenesis of COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationships between plasma digoxin-like immunoreactivity (DLS) and atrial natriuretic peptide (ANP) were investigated in 10 young essential hypertensives (mean age 22 +/- 2 years) and in 10 normotensives. In young hypertensives, plasma DLS and ANP were at an average level of 31.2 +/- 8 pg/ml and 56.7 +/- 20 pg/ml respectively, showing a significant correlation (r = 0.66; p less than 0.05). In normal subjects plasma DLS and ANP were at an average level of 19.1 +/- 8 pg/ml and 37.6 +/- 16.7 pg/ml respectively (n.s.). Plasma DLS and ANP were higher in hypertensives than in normotensives (p less than 0.01). In conclusion, DLS and ANP appear to have a similar behaviour, possibly due to their modulation by common stimuli.

We performed an epidemiological study on the atrial natriuretic factor pattern in a young population. Subjects were recruited in the Ospedale Militare Principale of Rome among young men liable to conscription, whose hospitalization was due either to essential hypertension or to other pathologies (not influencing our study, such as headache etc.). The recruitment lead to the formation of three different groups: normotensives, normotensives with family history of hypertension (mother and/or father) and hypertensives. On the morning of the study (after 7 days of pharmacological wash-out, under a diet containing 120 mEq of Na+/die), blood samples were taken. Plasma atrial natriuretic factor, renin activity and aldosterone were assayed by RIA. Digoxin-like immunoreactive substance was assayed by a solid-phase radioimmunoassay, following the extraction of plasma. Serum creatinine, sodium, potassium and urinary sodium and potassium (24 h before the study) were assayed by standard methods. Urinary kallikrein was assayed by chromogenic substrate S-2266. So far, we have studied 60 subjects (26 hypertensives, 21 normotensives and 13 normotensives with family history) and we wish to discuss in this article the preliminary results concerning the atrial natriuretic factor and its relationship with renin activity, aldosterone and blood pressure. Our results show that the mean plasma levels of atrial natriuretic factor in the hypertensive group were higher, although not significantly, than those of the other two groups and that the normotensives with family history had slightly higher levels as compared to normotensives (Delta % = + 7.4).(ABSTRACT TRUNCATED AT 250 WORDS)