QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Johnson, W. T. Articles by Dufault, S. N. Search for Related Content PubMed PubMed Citation Articles by Johnson, W. T. Articles by Dufault, S. N.

Altered Cytoskeletal Organization and Secretory Response of Thrombin-Activated Platelets from Copper-Deficient Rats^{1 ,2}

United States Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202

The cytoskeletal reorganization that occurs following thrombin-induced activation of platelets was investigated in rats consuming either a copper-deficient diet containing less than 1 µg Cu/g or a copper-adequate diet containing 5.5 µg Cu/g. Within 30 s following thrombin activation, the amount of polymerized actin in Triton X-100 extracts of whole platelets from copper-deficient rats was greater than the amount in platelets from copper-adequate rats. Electrophoretic analysis of the cytoskeletal proteins obtained from low speed centrifugation of the Triton X-100 extracts indicated that the myosin content of the cytoskeleton increased with time and reached higher levels following activation in platelets from copper-deficient rats. Actin content of the cytoskeleton also increased with time following activation. However, the difference in cytoskeletal actin content of platelets from copper-deficient and copper-adequate rats was not as great as that observed for myosin. The rate of ATP secretion from thrombin-activated platelets was also increased by copper deficiency. Myosin association with the platelet cytoskeleton may be involved in platelet secretion following thrombin activation. Thus, the increased association of myosin with the cytoskeleton and concomitant increase in ATP secretion suggest that the normal mechanism for stimulus-response coupling is altered in thrombin-activated platelets from copper-deficient rats.

KEY WORDS: • copper deficiency • platelets • cytoskeleton • stimulus-response coupling • male rats

¹ Presented in part at the 72nd Annual Meeting of the Federation of American Societies for Experimental Biology, Las Vegas, NV, May 1–5, 1988 [FASEB J. 2: A1422 (abs.)].

² Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture, and does not imply its approval to the exclusion of other products that may also be suitable.

Manuscript received 11 November 1988. Revision accepted 5 June 1989.