ABSTRACT
Objective To evaluate the toxicological safety of antithrombotic small peptide RWR with independent intellectual property right. Methods Toxicity test in mice, mice bone marrow micronucleus assay, mice sperm abnormality test, and 30-day feeding test in rats were carried out in this study.ResuIts The MTD of acute toxicity test for rats was larger than 120 mg/kg.The results of bone marrow micronucleus assay, mice sperm abnormality test were all negative.Thirty-day feeding test had no adverse effects on body weight, food utility rate, organ coefficient, blood routine index of rats.There was also no histological changes related to RWR in lung, liver, spleen, kidney and heart of rats.ConcIusion RWR had no obvious toxicity on animal growth, hematopoietic function, kidney function and organ tissue and so on.
ABSTRACT
The intermediate conductance Ca2+-activated K+ channels (SK4, IKCa1) are present in lymphocytes, and their membrane expression is upregulated by various immunological stimuli. In this study, the activity of SK4 was compared between Bal-17 and WEHI-231 cell lines which represent mature and immature stages of murine B lymphocytes, respectively. The whole-cell patch clamp with high-Ca2+ (0.8microM) KCl pipette solution revealed a voltage-independent K+ current that was blocked by clotrimazole (1 mM), an SK4 blocker. The expression of mRNAs for SK4 was confirmed in both Bal-17 and WEHI-231 cells. The density of clotrimazole-sensitive SK4 current was significantly larger in Bal-17 than WEHI-231 cells (-11.4+/-3.1 Vs. -5.7+/-1.15 pA/pF). Also, the chronic stimulation of B cell receptors (BCR) by BCR-ligation (anti-IgM Ab, 3microgram/ml, 8~12 h) significantly upregulated the amplitude of clotrimazole-sensitive current from -11.4+/-3.1 to -53.1+/-8.6 pA/pF in Bal-17 cells. In WEHI-231 cells, the effect of BCR-ligation was significantly small (-5.7+/-1.15 to -9.0+/-1.00 pA/pF). The differential expression and regulation by BCR-ligation might reflect functional changes in the maturation of B lymphocytes.