Under anesthesia and artificial respiration, all the dogs were injected with HCN 8 mg/kg intravenously. 2 minutes after HCN injection, 4-dimethylaminophenol( DM -AP) 3.2mg/kg,sodium nitrite(NaNO2)20 mg/kg,or dicobalt edetate(Co2EDTA) 15 mg/kg was given intravenously to different animals respectively. The changes of hemodynamics of the dogs were observed before and after the administration of the 3 HCN antidotes.It was found that intravenous injection of HCN rapidly induced a progressive decrease of heart rate(HR),stroke index(SI), cardiac index (CI),mean aortic pressure (MAP),left ventricular pressure(LVP) and ?dp/dtmax and a persistent increase of total peripheral vascular resistance (TPVR) and mean pulmonary arterial pressure (MPAP). If not treated,the dogs would died subsquently 4-9.5 minutes after HCN injection because of cardiac failure.2 to 8 minutes after DMAP administration, CI, MAP, LVP and?dp/dtmax increased markedly,and TPVR and MPAP would recover a little later. 4-6minutes after NaNO2 administration, ?dp/dtmax increased markedly, and CI, MAP, LVP, TPVR and MPAP returned to the normal. 6 minutes after Co2EDTA administration, MAP elevated markedly, LVP and?dp/dtmax returued to the normal, and C1, TPVR and MPAP would recover a little later. When observation was made again one hour after treatment, there was a remarkable decrease of blood pressure in NaNO2 and Co2EDTA treated animals and a slight decrease of blood pressure in DMAP treated ones.The conclusions based on the results are as follows:1. The ability of DMAP to restore the circulatory functions after HCN poisoning is more rapid and powerful than that of Co2EDTA or NaNO2.2. The cardiovascular functions restored by DMAP are more stable than those restored by the other two agents.3. DMAP and NaNO2 can rapidly reverse the HCN-iuduced damages on the cardiovascular functions, which may be a part of the anticyanide ability of these 2 drugs.

Effects of soman on lymphocyte proliferation are investigated in mice. 1 d after soman(154 ?g/kg,sc) poisoning B-lymphocyte reaction to lipopolysaccharide(LPS) is inhibited significantly and is persistent.T-cell proliferation response stimulated by concanavalin(Con A)has a 2-phase changeson the 1st day an increase followed by a dramatical reduction. Both the decreases of T-and B-lymphocyte mitogenic response and the primary increase of T-cell response show a close correlation with the doses of soman in this experiment. It has no relation to the change of the whole blood cholinesterase activity.

Co2EDTA-DMAP.HCl.