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Updated: Aug 5, 2026

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain
08:32

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Insulin pathway components and insulin effects on rho kinase in rat colon

Othman Abdullah Al-Shboul1, Ahmed N Al-Dwairi2, Abdulsalam K Bani Hamad2

  • 1Department of Physiology and Biochemistry, Faculty of Medicine, University of Science and Technology, Irbid, 22110, Jordan. oashboul@just.edu.jo.

Molecular Biology Reports
|July 29, 2026
PubMed
Abstract

Insights

Insulin signaling components are present in the rat colon. Insulin reduces RhoA/Rho-associated protein kinase (ROCK) activation, suggesting a role in modulating gastrointestinal smooth muscle contraction.

Area of Science:

  • Gastroenterology
  • Endocrinology
  • Molecular Biology

Background:

  • The RhoA/Rho-associated protein kinase (ROCK) pathway regulates smooth muscle contraction.
  • Insulin's effect on gastrointestinal (GI) smooth muscle ROCK activity is largely unknown.
  • Insulin signaling involves the insulin receptor (IR), insulin receptor substrates (IRS), and phosphoinositide 3-kinase (PI3K).

Purpose of the Study:

  • To characterize insulin signaling components in the rat colon.
  • To determine if insulin affects ROCK activity in the colon.

Main Methods:

  • Immunohistochemistry (IHC) for IR protein localization.
  • Quantitative PCR for mRNA expression of IR, IRS, PI3K, and ROCK isoforms.
  • ROCK activity assay to measure insulin's effect on acetylcholine-induced activation.

Main Results:

  • IR protein expressed in rat colon mucosa and muscle layers.
  • Differential mRNA expression of IRA, IRS2, p110α, and ROCK2.
  • Insulin significantly reduced acetylcholine-induced ROCK activation.

Conclusions:

  • The colon expresses key insulin signaling molecules.
  • Insulin modulates ROCK activity in the colon.
  • Insulin may regulate colonic contractile signaling via ROCK.
Keywords:
ROCKcoloncontractioninsulin signalingsmooth muscle

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