Nephrectomy abolishes the increase in small acetylcholinesterase-positive immature rat megakaryocytes induced by acute thrombocytopenia.

The effect of unilateral nephrectomy, bilateral nephrectomy, or ureter ligation on the proportion of small acetylcholinesterase-positive (SAChE+) cells was determined in the marrow of rats that were made acutely thrombocytopenic by an injection of platelet specific antiserum (APS). APS caused significant increases (P less than 0.025-P less than 0.005) in the percentages of SAChE+ cells in the marrow of rats except in those rats that had been subjected to bilateral nephrectomy. Bilaterally nephrectomized rats not only failed to show increased numbers of SAChE+ cells after being made thrombocytopenic but other anephric rats that were not given APS had decreased percentages of SAChE+ cells (P less than 0.005) when compared to untreated control rats. This finding indicates the importance of the kidney in the day-to-day production of a thrombocytopoiesis-stimulating factor (TSF) for the maintenance of SAChE+ cells. Unilateral nephrectomy and ligation of the ureters had little effect on altering the percentages of SAChE+ cells, suggesting that surgical stress and uremia do not interfere in the release and action of TSF. This study confirms previous work that the kidney is required for the production of TSF.