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In vivo changes in free choline level induced by autonomic agonists in mouse organs, including three major salivary

T Kawaguchi1, S Murai, H Saito

  • 1Department of Biochemistry, School of Dentistry, Iwate Medical University, Morioka, Japan.

Comparative Biochemistry and Physiology. Toxicology & Pharmacology : CBP
|March 15, 2001
PubMed

Insights

Autonomic agonists like isoproterenol alter free choline levels in mouse organs. Repeated isoproterenol injections increase choline accumulation in salivary glands, suggesting autonomic control of choline signaling.

Area of Science:

  • Physiology
  • Pharmacology
  • Biochemistry

Background:

  • Free choline is crucial for cellular functions.
  • Autonomic nervous system regulates various physiological processes.
  • The role of autonomic agonists in modulating in vivo choline levels remains largely unexplored.

Purpose of the Study:

  • To investigate the impact of different autonomic agonists on free choline levels in various mouse organs.
  • To determine the dose- and frequency-dependency of choline level changes induced by isoproterenol.
  • To elucidate the signaling pathways involved in autonomic control of choline.

Main Methods:

  • Subcutaneous injections of autonomic agonists (isoproterenol, phenylephrine, pilocarpine) in mice.
  • Measurement of free choline levels in whole organs and specific tissues (salivary glands).
  • Repeated administration of agonists and assessment of delayed and accumulated choline levels.
  • Investigation of signaling pathways using adenylyl cyclase activators and receptor antagonists.
  • Correlation of choline levels with salivary gland weight and diet.

Main Results:

  • Isoproterenol, phenylephrine, and pilocarpine caused rapid, transient changes in organ choline levels.
  • Repeated isoproterenol injections led to significant choline accumulation in salivary glands, particularly the parotid gland.
  • Choline accumulation was dose- and frequency-dependent, with repeated injections at 2-day intervals showing augmented effects.
  • Isoproterenol-induced immediate choline lowering was downstream of cAMP synthesis and linked to beta1-adrenergic receptors.
  • Salivary gland choline levels were influenced by diet and correlated with gland weight.

Conclusions:

  • This study provides the first evidence for autonomic control of intracellular free choline levels in vivo.
  • Autonomic agonists, particularly beta1-adrenergic receptor agonists, can modulate choline levels in specific organs like salivary glands.
  • Intracellular choline levels may represent an integral component of autonomic signaling pathways.
  • Diet and gland physiology also influence choline levels in salivary glands.

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