Abstract: Aim The distribution of four antibiotics:penicillin G,cefazolin,tobramycin and clindamycin in the nucleus of intervertebral discs in New Zealand rabbit was studied.Methods At 0.5 and 1 hour after ear intravenous injection,the concentration of four antibiotics in serum and in nucleus in infected intervertebral discs of rabbits were determined by high performance liquid chromatography methods.The antibiotic concent rations of serum and nucleus w ere compared.Results The ratios of nucleus to serum antibiotic concentration were ranged from low to high in asequence of penicilin G,cefazolin,tobramycin and clindamycin.The ratioes for the antibiotics,except for penicillin G,were increased in infected rabbit,with the ratios for tobramycin and clindamycin increased markedly (P<0.05).The rate of removing on the antibiotics from nucleus was lower than from serum.Conclusion There is no interrelation of cerum and nucleus in antibiotic concentrations.Clindamycin and tobramycin are the antibiotics of shoice in treating infected intervertebraldiscs.

Key words: uncleus, antibiotics, serum drug concentration, drug distribution, high performance liquid chromatography