ETA and ETB receptor function in pancreatitis-associated microcirculatory failure, inflammation, and parenchymal injury

Am J Physiol Gastrointest Liver Physiol. 2003 Jul;285(1):G145-53. doi: 10.1152/ajpgi.00181.2002.

Abstract

The role of endothelin (ET)A and ETB receptor function in experimental pancreatitis is still not fully understood. Using a rat model of sodium taurocholate-induced pancreatitis and intravital microscopy, we therefore studied whether selective inhibition of ETA receptor function or combined ETA and ETB receptor blockade affects the development of pancreatitis-associated microcirculatory failure, inflammation, and parenchymal injury. Pretreatment with 10 mg/kg body wt of a combined ETA/B receptor antagonist, which is thought to mediate a simultaneous inhibition of both receptors, did not attenuate the pancreatitis-induced microcirculatory failure, inflammatory response, and parenchymal tissue injury. In contrast, pretreatment with a low concentration of the combined ETA/B receptor antagonist (4 mg/kg body wt), which predominantly inhibits the ETA receptor, revealed an improvement of some microcirculatory disorders and a significant attenuation of leukocyte recruitment and tissue injury. Furthermore, pretreatment with a selective ETA receptor antagonist (1 microg/kg body wt) almost abolished pancreatitis-associated capillary constriction, restored functional capillary density, and, consequently, improved overall nutritive perfusion. Importantly, the maintenance of an appropriate microcirculation by selective ETA receptor inhibition was accompanied by a significant attenuation of the inflammation-associated leukocytic response and by a marked reduction of parenchymal injury. Thus our study indicates that pancreatitis-associated development of microcirculatory failure, inflammation, and parenchymal injury is caused by ETs coupling onto the ETA receptor, which therefore may represent a promising target for novel strategies in the treatment of pancreatitis.

MeSH terms

  • Animals
  • Blood Flow Velocity
  • Capillaries / pathology
  • Capillaries / physiology
  • Cholagogues and Choleretics
  • Disease Models, Animal
  • Endothelin Receptor Antagonists
  • Male
  • Pancreas / blood supply*
  • Pancreas / immunology
  • Pancreas / metabolism
  • Pancreatitis, Acute Necrotizing / drug therapy
  • Pancreatitis, Acute Necrotizing / metabolism*
  • Pancreatitis, Acute Necrotizing / physiopathology*
  • Pyridines / pharmacology
  • Rats
  • Rats, Inbred Lew
  • Receptor, Endothelin A
  • Receptor, Endothelin B
  • Receptors, Endothelin / metabolism*
  • Taurocholic Acid
  • Tetrazoles / pharmacology
  • Vasodilator Agents / pharmacology

Substances

  • Cholagogues and Choleretics
  • Endothelin Receptor Antagonists
  • Pyridines
  • Receptor, Endothelin A
  • Receptor, Endothelin B
  • Receptors, Endothelin
  • Tetrazoles
  • Vasodilator Agents
  • Taurocholic Acid
  • tezosentan