Cold acclimation induces zonal heterogeneity in gluconeogenic responses to glucagon in rat liver lobule

Am J Physiol. 1995 Jun;268(6 Pt 1):E1184-91. doi: 10.1152/ajpendo.1995.268.6.E1184.

Abstract

The relationship between the enhanced responses of gluconeogenesis to norepinephrine (NE) and glucagon and its zonal distribution was studied in liver lobules of cold-exposed rats by examination of preparations enriched for periportal hepatocytes (PP-H) and for perivenous hepatocytes (PV-H) by the digitonin-collagenase perfusion technique. In the control group, gluconeogenesis from lactate (10 mM) plus pyruvate (1 mM) was higher in PP-H than in PV-H. NE (100 nM) and glucagon (100 nM) increased the rate of gluconeogenesis by 80 and 70%, respectively, in both PP-H and PV-H. Gluconeogenesis in PP-H was unchanged by cold exposure. The rate in PV-H increased to the rate in PP-H at 5 days after cold exposure, and then the rate returned to the control value at 20 days. The gluconeogenic response to the alpha-adrenergic action of NE in both PP-H and PV-H doubled after 5 days. The response to glucagon tripled in PP-H and was cut in half in PV-H after 20 days. Phorbol 12-myristate 13-acetate (PMA; 1 microM), A-23187 (100 nM), and dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP; 1 mM) increased the rate of gluconeogenesis by 200, 100, and 80%, respectively, in both PP-H and PV-H from the control group. The responses to PMA and A-23187 were unchanged by exposure to cold. The response to DBcAMP was doubled in PP-H and was cut in half in PV-H after 20 days of cold exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acclimatization*
  • Animals
  • Bucladesine / pharmacology
  • Calcimycin / pharmacology
  • Cells, Cultured
  • Cold Temperature
  • Fructose-Bisphosphatase / metabolism
  • Glucagon / pharmacology*
  • Gluconeogenesis / drug effects
  • Gluconeogenesis / physiology*
  • Glutamate-Ammonia Ligase / metabolism
  • Kinetics
  • Liver / drug effects
  • Liver / metabolism*
  • Male
  • Norepinephrine / pharmacology*
  • Phosphoenolpyruvate Carboxykinase (GTP) / metabolism
  • Phosphofructokinase-1 / metabolism
  • Pyruvate Kinase / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Adrenergic, alpha / physiology
  • Signal Transduction
  • Tetradecanoylphorbol Acetate / pharmacology
  • Time Factors

Substances

  • Receptors, Adrenergic, alpha
  • Calcimycin
  • Bucladesine
  • Glucagon
  • Phosphofructokinase-1
  • Pyruvate Kinase
  • Fructose-Bisphosphatase
  • Phosphoenolpyruvate Carboxykinase (GTP)
  • Glutamate-Ammonia Ligase
  • Tetradecanoylphorbol Acetate
  • Norepinephrine