Junichi Soneda

α-Human atrial natriuretic polypeptide is released from the heart and circulates in the body

In order to clarify whether or not atrial natriuretic polypeptides are hormones in man, we have measured plasma alpha-human atrial natriuretic polypeptide (alpha-hANP)-like immunoreactivity (alpha-hANP-LI) with or without extraction procedure. alpha-hANP-LI was detected in plasma extracts from all 5 normal subjects and 7 patients with heart diseases. The alpha-hANP-LI concentration in normal peripheral plasma was 37.7 +/- 7.0 pg/ml (mean +/- SE). Plasma concentrations of alpha-hANP-LI in the coronary sinus obtained by cardiac catheterization were 3 to 10 times higher than those in the peripheral vein, inferior vena cava, right atrium, pulmonary artery and aorta. High performance gel permeation chromatography coupled with a radioimmunoassay (RIA) for alpha-hANP revealed that alpha-hANP-LI in normal peripheral plasma eluted at the position corresponding to that of authentic alpha-hANP without detectable amounts of high molecular weight forms. alpha-hANP-LI extracted from plasma taken from the coronary sinus of two patients also showed a single peak of alpha-hANP-LI co-eluting with alpha-hANP. In contrast, not only alpha-hANP but gamma-hANP and beta-hANP, high molecular weight forms, were present in the human atrial tissue. These results indicate that alpha-hANP is the predominant form of alpha-hANP-LI in human plasma and that this form generated in the atrial cardiocytes is preferentially released from these cells and circulates in the body.

Radioimmunoassay for α-human and rat atrial natriuretic polypeptide

Abstract Using a synthetic common carboxy-terminal fragment of α-human atrial natriuretic polypeptide (α-hANP) and α-rat atrial natriuretic polypeptide (α-rANP), we have produced an antiserum for α-ANP(17–28) and established a radioimmunoassay (RIA) for α-ANP that recognizes α-hANP and α-rANP equally. High performance gel permeation chromatography coupled with the RIA revealed that α-hANP-like immunoreactivity (α-hANP-LI) in the human atrium consists of three major components, γ-hANP, α-hANP and another. On the other hand, α-rANP-LI in the rat atrium comprised at least two components, 13K α-rANP-LI and 3K–5K α-rANP-LI, which were presumably γ-rANP and β-rANP, respectively. Thus, considerable amounts of γ-hANP and γ-rANP are present in human right auricles and rat atria, respectively. The RIA established in this study provides a useful tool to investigate the pathophysiological significance of α-ANP and related peptides in cardiovascular disorders and shows that γ-ANP is not only a precursor of α-ANP but acts as an important hormone.

Clinical application of left ventricular assist devices.

In Japan, 32 patients have had application of monoventricular and biventricular assist devices during the past three years. Five of the 32 patients treated by the Fall of 1986 have successfully achieved long‐term survival. In this paper we describe our experience with the Tomasu and Pierce VAD in a total of four and two patients, respectively. Four of the six patients could be successfully weaned from the VAD and two of them were long‐term survivors. Nonsynchronizing pumping of the VADs was effective, as well as synchronizing pumping. Anticoagulant therapy is highly recommended during the use of the VAD although there was no significant incidence of thromboembolism or thrombus in the devices in this clinical series.