You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

The suppression of hematopoiesis function in Balb/c mice induced by prolonged exposure of microcystin-LR. Microcystins (MCs) cause normocytic anemia in patients in a hemodialysis unit in Caruaru, Brazil in 1996, but the underlying mechanisms are still unclear. In the present study, Balb/c mice were intraperitoneally injected with microcystin-LR (MC-LR) at the doses of 0.5, 2 and 8μg/kg body weight (bw) every 48h for 30d. After the prolonged exposure of MC-LR, significant decreases of red blood cell count (RBC), hemoglobin (Hb) and hematocrit (Ht) were observed in 2 and 8μg/kg bw groups, but erythrocyte mean corpuscular volume (MCV) showed no significant changes. Significantly elevated micronucleus frequency was observed in bone marrow cells (BMCs) in all MC-LR treatments. The proliferation of BMCs significantly declined in both 2 and 8μg/kg bw groups. Serum levels of some hematopoietic growth factors significantly changed in 8μg/kg bw group, mainly including granulocyte-macrophage (GM-CSF), erythropoietin (EPO), interleukin-3 (IL-3) and TNF-α. The transcriptional levels of these 4 genes in BMCs were also significantly changed in 8μg/kg bw group. MC-LR exposure significantly increased the apoptosis rates in all MC-LR treatments. The present study indicates prolonged exposure of MC-LR induces normocytic anemia, and the disturbed hematopoietic growth factors and BMCs apoptosis are responsible for this normocytic anemia.
{"Chemical": ["microcystin-LR", "MC-LR", "Microcystins"]}