Increasing evidence indicates the presence of endogenous digitalis-like compound(s) in human body fluids. In this preliminary report, we describe a study of the partial purification by HPLC of these compounds in the plasma of neonates (who have particularly high concentrations of this substance) and adults. Plasma samples from neonates (cord blood) and adults, lyophilized and extracted with methanol, were applied on a 300 x 3.9 mm C18 Nova Pak column and eluted with a mobile phase of acetonitrile/methanol/water (17/17/66 or 14/14/72 by vol) and, after 30 min, with 100% methanol. We assayed eluted fractions for inhibitory activity of 86Rb uptake and for digoxin-like immunoreactivity. The elution profile revealed a first peak of inhibitory activity of 86Rb uptake at the beginning of the chromatography; another peak was eluted with the 100% methanol. The two peaks also cross-reacted with antidigoxin antibodies. Because the second peak could possibly reflect the nonspecific interference of various lipophilic compounds, we focused our attention on the first peak. For these fractions dose-response curves for 86Rb uptake and for displacement of digoxin were parallel, respectively, to those of ouabain and digoxin, suggesting similarities of digoxin-like immunoreactive substance to cardiac glycosides. Similar chromatographic profiles were also obtained for plasma from adults, suggesting that the endogenous glycoside-like compound(s) in the neonate may be the same as those in the adult.

Our results suggest that inhibins A and B are not useful markers and that HCG determination still remains the most useful marker for diagnosis and follow-up of placental tumours.

parathyroid gland, medullothyroid gland, and pancreas f3 cells), l,25-dihydroxyvitamin D, and enzymes are involved (3,4). Moreover, arteriosclerosis and atherosclerosis are calcium-dependent (3, 5). In IDD women, the significant negative correlation between P1-Ca and total cholesterol might be accounted for by the internalization of the calcium or even the cholesterol in the artery wall at a younger age, depending on whether cholesterol or calcium increased in their plasma. Thus, an increase in plasma cholesterol could allow P1-Ca to penetrate into the artery intima, to form atherosclerotic plaques in patients for whom atherosclerosis is very common and occurs early (4). The Bogalusa Heart Study (Framingham Junior survey) has just provided additional proof that cholesterol is one, if not the major, cause of atherosclerosis (6). Could calcium be the missing piece in this puzale of atherosclerotic plaque formation? Once again, biological results are not the same for both sexes (2-4). The epidemiologic, clinical, ergometric, and therapeutic particularities of women presenting with coronary insufficiency have just been described (7). Our results raise questions that were not resolved in that study, and suggest that much work remains to be done. References 1. Speich M. More on the relation between magnesium and calcium in serum and plasma [Letter].

Plasma and urinary adrenaline and noradrenaline (A and NA), PBI, he art rate (HR), creatinine c\earance (CC) and arterial pressures (AP) have been measured by the Renzini et al. (1970) method in 9 hyperthyroid, 4 hypothyroid and 13 euthyroid patients. NA plasma concentration was found nonnal or subnormal in hyperthyroids (271.7 ± 140.3 ng/l) in comparison to nonnals (272.5 ± 115 ng/I) and markedly increased in hypothyroids (505 ± 154.6 ng/1). Adrenaline concentration showed the same pattern (51.7 ± 23.9 ng/1) in hyperthyroids, 53.1 ± 6.8 ng/I in euthyroids and 63.1 ± 12.3 ng/I in hypothyroids and so did urinary excretion both during night and day.Changes induced by treatment in two hyper-and one hypothyroid were consistent with this pattern. These results agree with and extend those recently reported for total catecholamines by Stoffer et al. (1973) and by Christensen (1973) for NA.No correlation whatsoever was found between plasma A or NA and HR, AP or CC. On the other hand, both HR ( Figure) and CC correlate weH with PBI concentration suggesting that hemodynamic changes in thyroid disease are mostly due to the thyroid honnone itself. HR min-1 125 100 • o 75 • 50 Figure Rec.: IS Oet.1973 y a 3.+71.3 r = 0.74 pe 0.001 • hypothyroids • euthyroids o hyperthyroids PB I ),9/lOOccInverse relationship between thyroid functional level and catecholamines concentration, may reflect either a cornpensatory adjustment of the neuroadrenergic system, or a metabolie c1earance rate of the amines varying directly with the level of eirculating thyroid hormone.

A hereditary defect in the outward ouabain-resistant, furosemide-sensitive (ORFS) Na+/K+ cotransport has recently been reported by Garay and Meyer in erythrocytes of essential hypertensive patients and some of their normotensive offsprings. Since Na+/K+ cotransport in erythrocytes operates bidirectionally, the same defect might be detectable in the ORFS component of K+ influx rate. To test this hypothesis outward and inward Na+/K+ cotransport measurements were performed in erythrocytes of hypertensives and normotensive controls. Our preliminary results confirm the observation of a reduced outward cotransport in essential hypertension and also suggest that inward cotransport may be reduced in essential hypertension.