Effects of Three Antivirals on Platelets and Megakaryocytes in Rabbits

Objective To appraise the effects of ribavirin,ganciclovir and vidarabine on the peripheral blood platelets and megakaryocytes of the bone marrow in rabbits. Methods 20 rabbits were randomly divided into 4 equal groups.Animals of the groups A,B,C and D were given each a daily IV injection of 15 mg·kg~(-1)of ribavirin,10 mg·kg~(-1)of ganciclovir,10(mg·kg~(-1))of vidarabine and an equivalent amount of 0.9% sodium chloride solution via the marginal vein of the ear,respectively.The course of treatment lasted 14 days.During the treatment course,samples of peripheral blood were collected every 4 days for platelet counting.1 day as well as 8 days after the termination of the treatment,bone marrow was aspirated for the counting of megakaryoeytes. Results 1 day after the termination of treatment,the numbers of the bone marrow megakocyocytes in rabbits of group A and group B were smaller than that in rabbits of group D(P0.05),while the megakaryocyte number in animals of group C was even still smaller than that in animals of group D(P0.01).8 days after the termination of treatment,bone marrow megakarypocytes in rabbits of group A,B and C were shown to have undergone considerable degrees of restoration in number.A good correlation between megakaryocytes and platelets was demonstrated(r=0.999,P0.05).During the course of treatment,the platelet countings showed a sharp increase at first followed by a gradual fall in rabbits of group A,a sustained decline in animals of group C and no impressive changes in rabbits of group B and group D. Conclusion Different antivirals were shown to have different effects on megakaryocytes and platelets in rabbits,suggesting that one should be prudent in the choice of drugs for patients with disorders of platelet and hemopoietic functions.