ISSN:
1573-4919
Keywords:
Ca2+-ATPase
;
calcium
;
nuclear DNA
;
DNA fragmentation
;
regucalcin
;
regenerating rat liver
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract The alteration of calcium content, Ca2+-ATPase activity, DNA content and DNA fragmentation in the nuclei of regenerating rat liver was investigated. Liver was surgically removed about 70% of that of sham-operated rats. the reduced liver weight by partial hepatectomy was completely restored at 3 days after the surgery. Regenerating liver significantly increased Ca2+-ATPase activity and DNA content in the nuclei between 1 and 5 days after hepatectomy. The nuclear calcium content was clearly increased from 2 days after hepatectomy. The increase of Ca2+-ATPase activity in regenerating liver was clearly inhibited by the presence of trifluoperazine (10 μM), staurosporine (2.5 μM) and dibucaine (10 μM), which are inhibitors of calmodulin and protein kinase, in the enzyme reaction mixture. However, the nuclear enzyme activity in normal rat liver was not significantly altered by these inhibitors. Meanwhile, the increase of nuclear DNA content in regenerating liver was completely blocked by the administration of trifluoperazine (2.5 mg/100 g body weight), suggesting an involvement of calmodulin. Now, the nuclear DNA fragmentation was significantly decreased in regenerating liver, suggesting that this decrease is partly contributed to the increase in nuclear DNA content. The present study clearly demonstrates that regenerating liver enhances nuclear Ca2+-ATPase activity and induces a corresponding elevation of nuclear calcium content. This Ca2+-signaling system may be involved in the regulation of nuclear DNA functions in regenerating rat liver.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00944611
