The effects of Radix Ginseng rubra on cAMP of experimental ischemic myocardium in rats.

The model of SD rats ligated at the proximate left anterior descend (LAD) of coronary was used. The number and dissociation constant of beta receptor were studied by using receptor autoradiography to observe the changes in beta receptor and the effects of Radix Ginseng Rubra on cAMP in experimental ischemic myocardium. The result showed that the number of binding site in simple ligation group (Bmax = 0.279) was obviously higher than that in sham operation group (Bmax = 0.093) and the dissociation constant of simple ligation group (Kd = 12. 431) was higher than that of sham operation group (kd = 1.319). There was a significant difference between the two groups (P < 0.05). It proved that the number of beta receptor was increased and the activity was elevated in myocardial cell membranes after ligation of LAD. The myocardial cAMP level in simple ligation group [(1293.96 +/- 519.36) x 10(-3) nmol/g] was much higher than that in sham operation group [(774.44 +/- 210.55) x 10(-3) nmol/g]; but the level of cAMP in ligation group after receiving Radix Ginseng Rubra treatment (805.02 +/- 362.48 pm/g) was obviously lower than that in simple ligation group (P < 0.01), which was close to the result of sham operation. The results indicated that Radix Ginseng Rubra could decrease the cAMP level in ischemic myocardium.