STUDY OF THE EFFECTS OF NON-SELECTIVE BETA-ADRENERGIC TREATMENT ON PLASMA THROMBOCYTOPOIETIN ACTIVITY [IN RATS IN CONDITIONS OF AN ACUTE THROMBOCYTOPENIA

N Negrev
unpublished
The relation between the count of peripheral blood thrombocytes and plasma hrombocytopoietin activity is long ago established. It is known that normally, thrombocytopenia is attended by thrombocytopoietin production increase (8, 10) whereas any thrombocytosis-by its decrease (6, 13). Our previous studies show that thrombocytopoietin production in rats in ormal conditions depends also on beta-adrenergic receptors (1, 3). On the basis f that we make it our object to studying to what extent
more » ... ective (5-adre-ergic effects are related to plasma thrombocytopoietin activity in conditions of n acute thrombocytopenia. This could enable more profound conclusions con-rning the importance of non-selective ^-adrenergic influences and (i-adreno-ptors, respectively, on thrombocytopoietin production. Material and methods Plasma required for thrombocytopoietin activity determination was obtain-d from 53 male rats of Wistar breed with 180-220 g body weight divided into ree groups and injected as followed: I st group-with Isoprenaline (IP) hydro-hloride (a non-selective p-adrenostimulator) at dosis 2X3 mg/kg b. w.; II n d group-with Propranolol (PR) hydrochloride (a non-selective P-adrenoblocker) t dosis 2x5 mg/kg b. w., and III rd group-controls-with saline in the same mount. Injections were made intraperitoneally every 12 hours. 3 h after first pplication all the rats were injected with thromboplastin (TP) after the scheme f Kelemen et al. (7) in our modification, namely: We used TP produced by the esearch Institute of Hematology and Transfusion-_Sofia in our study. The "st injection was done in the tail vein in_yol. 0.5.10 6 m 3 but the second one "ter 40 min intraperitoneally in vol. 1.10 6 m 3. Thrombocyte count was deter-ined according to the method of Feissly et Ludin (4) at the beginning and the d of the assay. Animals were bleeded by means of aortic cannulation on the 20 th hour after first TP injection. Separated plasma was stored at-8° С for 10 days, е judged of plasma thrombocytopoietin activity from the changes of thrombo-te count and from 7 5 se lenomethionine (75 Se-M) incorporation in newly formed rombocytes in recipients-mice under the influence of material tested. We used 1 white male non-thoroughbred mice with 20-30 g b. w. divided into 3 groups, he animals from the first group were injected with plasma from donors treated ith IP+TP, those from the second one-with plasma from donors treated ith PR+TP, and the mice from the third group were controls (injected with plasma from donors treated with saline+TP). We tested the plasma after Pening-ton's method in our modification (12). It included the following changes:
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