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Intracellular potassium activity (aki), mucosal and serosal membrane potential (mEm, sEm), short-circuit current (Isc), and transepithelial potential difference in the epithelium of the toad bladder were measured with a potassium-sensitive liquid ion exchanger and an ordinary microelectrode. Under basal conditions, aki was 41.2 +/- 0.5 mM, corresponding to 54.4 mM in free potassium concentration, so half or more of the intracellular potassium may be of bound form or sequestrated within subcellular organelles. The sEm cannot be explained by only the potassium equilibrium potential (Eeq), because the sEm was markedly lower than the Eeq and no relation was found between them. Ouabain and rotenone decreased the aki, but ethacrynic acid, which also inhibited the Isc and the membrane potentials, did not show any effect on aki. Vasopressin decreased aki with an elevation in mEm, whereas prostaglandin E1 increased the aki with elevation in the sEm. These characteristic changes may afford an insight into the mechanisms by which transcellular electrolyte transport occurs.

Sixty-six children aged between 8 months and 15 years (average age 5.5 +/- 3.8 years) underwent mitral reconstructive operations for congenital mitral regurgitation between June 1969 and February 1987. The pathologic findings of the mitral valves were annular dilatation in 37 patients, cleft of the leaflet in eight, hypoplasia of the leaflet in 44, perforation of the leaflet in one, chordal elongation in 22, chordal absence in 16, and chordal shortening in seven. The methods of repair consisted of asymmetric annuloplasty (Kay-Reed method) in 61 patients, De Vega-type annuloplasty in one, plication of redundant leaflet in 15, and closure of cleft or perforation in nine. The single operative death (1.5%) was due to heart block. Follow-up data were available over 373.8 patient-years (average 5.7 years). The four late deaths (6.0%) were due to heart failure in two patients, pneumonia in one, and hepatitis in one. The actuarial survival rate was 93.1% +/- 3.1% at 7 years and 88.4% +/- 5.1% after 17 years. Valvuloplasty failed in 19 of the long-term survivors. One of these patients underwent mitral valve replacement 11 years after initial operation. The rate of freedom from reoperation was 86% +/- 10% after 17 years. The rate of freedom from valvuloplasty failure was 80% +/- 6.7% after 5 years, 67% +/- 7.2% after 10 years, and 44% +/- 11.9% after 15 years.

Effects of dopamine, N-methyl-, ethyl- and propyl-derivatives of dopamine, and alpha- and beta-adrenoceptor stimulants on catch contraction of anterior byssus retractor muscle of Mytilus edulis were tested. The test drugs except the beta-adrenoceptor stimulants relaxed catch contraction. Dopamine was most active and substitution of amino group in dopamine with ethyl and propyl decreased activity considerably. The concentration-curves of dopamine, its derivatives and norepinephrine shifted in parallel with application of haloperidol but were not influenced by the alpha- and beta-adrenoceptor antagonists. These results suggest that relaxation of catch contraction by catecholamines is mediated through a dopamine receptor. This muscle is considered to be suitable for a study of the dopamine receptor.

We followed up thirty-three patients, to whom the superior vena cava-pulmonary artery anastomosis (Glenn procedure) was undergone between April 1966 and March 1988. There were eighteen patients with single ventricle and nine with tricuspid atresia, two with pulmonary atresia with intact ventricular septum and four with other complex anomalies. Seven patients (21%), including six with single ventricle, died 0.3 to 14.9 years after operation. Regurgitation of common atrioventricular valve was the cause of death in three patients. Serum hemoglobin level fell down from 19.3 +/- 2.2 g/dl preoperatively to 15.3 +/- 1.9 g/dl after operation but increased gradually to the preoperative level about ten years later. The actuarial survival rate at ten years is 80%. Reoperation was performed in 9 patients and reoperation free rate at 10 years is 78%. This analysis suggests that Glenn procedure is still good palliative operation for ten years, although some patients will be necessitated the second operation in future.