Fig 1.
Changes in relative organ weights and reduction in spleen size in rats administered cocaine.
(A) Timeline of experimental procedures. Rats were administered cocaine (50 mg/kg) once daily, and sacrificed on day 1, day 3, or day 7. Filled arrowheads indicate cocaine administration. Open arrows indicate autopsy and sample collection from sacrificed rats. (B) Relative weights of indicated organs per body weights. In each graph, the mean relative weight of the control group was set to 1. Graphs show the means and S.D. of 6 samples. *P < 0.05 versus control by Student’s t-test. (C) Reduction in splenic volume in rats repeatedly administered cocaine (day 7).
Fig 2.
Histochemical and immunoblot analysis of spleen from rats repeatedly administered cocaine (day 7).
(A) Hematoxylin and eosin (H&E) and Elastica Masson-Goldner (EMG) staining of spleen. Black and white bars indicate 50 μm and 100 μm, respectively. (B-C) Immunoblot analysis of E-cadherin (B) and collagen type 1 (C). GAPDH levels served as the internal control. Graphs show the means and S.D. of 6 samples. *P < 0.05 versus control by Student’s t-test.
Fig 3.
Transcriptional profile of spleen from rats repeatedly administered cocaine (day 7).
Total RNAs from spleen (day 7) were subjected to DNA microarray and subsequent gene ontology (GO) analysis. (A) A scatter plot analysis of transcripts that showed greater than 2-fold responses to cocaine. The data below the lower dotted line indicate a greater than 2-fold increase caused by cocaine. The data above the upper dotted line indicate a greater than 2-fold decrease caused by cocaine. (B) Molecular function categories (Gene Ontology terms, GO) identified by Microarray Data Analysis Tool as being affected by cocaine in the spleen. P-values were calculated by comparison to the control group.
Table 1.
Categories related to RBC function that are significantly downregulated by cocaine.
Table 2.
List of 22 genes related to RBC that are included among the top 50 genes downregulated by cocaine.
Fig 4.
Repeated administration of cocaine upregulates contractile marker proteins, but not a marker of apoptosis in rat spleen.
Immunoblot analysis of cleaved caspase 3 (A), phosphorylated as well as total MYL (B) and transgelin (C) in the spleens of rats administered cocaine. GAPDH or actin levels served as internal controls. Graphs show the means and S.D. of 6 samples, except for phosphorylated MYL of the cocaine group of day 7 (5 samples). *P < 0.05 versus control by Student’s t-test.