This study was undertaken to determine the effect of hypoxia on the cable properties of the canine ventricular muscle, employing a single sucrose gap method. Hypoxia caused the internal longitudinal resistance, Ri, to increase by 25% (P<0.02) and the length constant, λ, to decrease by 13% (P<0.05), significantly. The control values of Ri and λ were 198 ± 76 Ω cm and 0.81 ± 0.15 mm (mean ± SD, n=5), respectively. The membrane resistance, Rm, (control; 3026 ± 581 Ω ㎠) decreased by 6%. The membrane capacitance and the time constant were not affected significantly.
It was also examined whether the increase in Ri during hypoxia could be caused by hyperkalemia or acidosis, which are known to occur during hypoxia. The results showed that Ri was unchanged under acidosis (pH 6.1) or high K+ concentration (10.8 mM), thus suggesting the direct effect of hypoxia on Ri.
These results suggest that the changes in the cable properties play important roles in the genesis of arrhythmias during hypoxia.
This study was conducted to examine the relation between conglutinin-like factors and other bacterial aggregating factors in human saliva.
Human and guinea pig complement intermediate cells (EAC4b,3b) were prepared by using an anticomplementary agent K-76 COONa.
Conglutinin-like factors and agglutinins for sensitized sheep erythrocytes in parotid and whole saliva from seven subjects were examined. Whole saliva from the subjects with a periodontal disease showed a lower activity than that from the subjects with a clinically normal gingiva. It seems, therefore, that some strum component from the gingival crevice inhibit the aggregation of sensitized sheep erythrocytes by saliva as in the case of the conglutination of EAC4b, 3b cells.
Conglutinin-like factors appeared over a wide region including both the void volume and the secretory IgA region in gel filtration of human whole saliva on Sepharose 4B. The void volume fractions contained a high conglutinin-like factor activity but no IgA activity. These data suggest that conglutinin-like factors are not polymers of IgA but complexes of glycoproteins or those on which IgA is bound furthermore.