Characterisation of penicillin-G uptake in rabbit small-intestinal brush-border membrane vesicles

Biochim Biophys Acta. 1996 Jan 31;1278(2):233-40. doi: 10.1016/0005-2736(95)00226-x.


Uptake of penicillin-G has been studied in rabbit intestinal brush-border membrane vesicles (BBMV). Penicillin-G was transported into the lumen of BBMV via an H+-dependent, Na+-independent uptake system. This was a saturable carrier-mediated process, which adhered to Michaelis-Menten kinetics, having a pH optimum of 4.5 and resulting in a net-negative charge transfer. Vmax was 59 nmol penicillin-G (mg protein)-1 (30s)-1 and Km 22.7 mM. Ampicillin, penicillin-V, cefadroxil, cephalexin, cephalothin, cephradine, L-carnosine, glycyl-L-alanine, glycyl-L-tyrosine and glycylglycylglycine inhibited the uptake of penicillin-G. However, glycylsarcosine stimulated uptake by 92%. Countertransport experiments suggested that this effect took place at the active site of the transporter. Penicillin-G uptake appeared to be mediated via a common transport system shared by penicillins, cephalosporins and peptides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / pharmacology
  • Animals
  • Biological Transport / drug effects
  • Electrochemistry
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Intestine, Small / metabolism*
  • Intestine, Small / ultrastructure
  • Kinetics
  • Lactams / pharmacology
  • Male
  • Membrane Potentials
  • Microvilli / metabolism*
  • Molecular Sequence Data
  • Oligopeptides / pharmacology
  • Penicillin G / pharmacokinetics*
  • Penicillins / pharmacokinetics*
  • Rabbits


  • Amino Acids
  • Lactams
  • Oligopeptides
  • Penicillins
  • Penicillin G