Abstract
Platelet abnormality in cirrhosis of the liver has been studied in our laboratory from biochemical, functional and morphological standpoint.
In this paper we studied the causes of shortening of platelet life-span in cirrhosis of the liver in relation to the splenomegaly, protein, sialic acid and glycoprotein contents of platelet and platelet plasma membrane.
[Result]
1) The volume of the spleen in cirrhosis of the liver measured from 99mTcscinti gram increased to 648cm3 against 307cm3 of normal control.
There was no significant correlation between the platelet counts and the spleen volume (r=0.02).
2) The protein content of the platelet increased to 2.0mg/109 plat. against 1.2mg/109 plat. of normal control.
3) The sialic acid content of the platelet decreased to 7.2μg/mg prot. against 9.6μg/mg prot. of normal control. And there was a good correlation between the platelet count and the platelet sialic acid content (r=0.65).
4) On 7.5% SDS polyacrylamide gel electrophoresis (SDS-PAGE) of the solubilized platelet protein, in cirrhosis of the liver, a new band of MW 46, 000 appeared, while a band of MW 41, 000 almost disappeared.
5) On SDS-PAGE of the solubilized platelet plasma membrane protein, the band of MW 156, 000 disappeared in both cirrhosis of the liver and normal control pretreated with neuraminidase.
6) On 5.6% SDS-PAGE of the solubilized platelet plasma membrane glycoprotein, three major peaks (I, II, III) were observed in both normal and hepatic cirrhosis, but in the latter, peak III of MW 88, 000 was smaller than that of the former. The simillar change was observed in normal platelet plasma membrane glycoprotein pretreated with neuraminidase.
From these findings, it may be suggested that in cirrhosis of the liver, the reduced platelet sialic acid or sialoglycoprotein may promote platelet break-down in reti culoendothelial system and shorten platelet life-span.
