Related Experiment Video
Updated: Jan 20, 2026
Contractility Measurements of Human Uterine Smooth Muscle to Aid Drug Development
Published on: January 26, 2018
Human circular colonic smooth muscle cells possess active somatostatin receptors
V D Corleto1, G Romano, C Severi
1Department of Human Biotechnology, La Sapienza University of Rome, Italy.
Background & Aims:
Somatostatin alters in vivo colonic motility in different species including humans. Few data are available on a cellular basis that could explain the effects of somatostatin on human colon motility. To address these issues we studied the effects of somatostatin on isolated human circular colonic smooth muscle cells to establish whether its actions are directly or neurally mediated.
Methods:
Circular smooth muscle cells were prepared by enzymatic digestion from surgical specimens of human colon (Sigma) and resuspended in HEPES buffer containing protease inhibitors.
Results:
Cholecystokinin (1 nM), carbachol (30 nM) and KCl (20 mM) each caused a contraction of 17%, 16.5% and 15%, respectively. 1 microM of either somatostatin-14, somatostatin-28 or SMS 201-995 alone were able to produce a contraction of 5.1%, 5.7%, and 6.8%, respectively. When smooth muscle cells were preincubated with each of the above-mentioned somatostatin analogs, cholecystokinin-mediated contraction was dose-dependently inhibited only in the presence of antiproteases. The half-maximal effective concentration (EC50) for somatostatin-14, somatostatin-28 and SMS 201-995 were similar (3.5, 5.6, 3.2 nM, respectively).
Conclusions:
Somatostatin acts directly on human circular colonic smooth muscle cells through specific somatostatin receptors. SMS 201-995, a somatostatin receptor subtype-2 preferring analogue, shows a high affinity in inhibiting cholecystokinin-mediated contraction, suggesting the presence of somatostatin receptor subtype-2 on human circular colonic smooth muscle cells.
Insights
Somatostatin directly impacts human colon smooth muscle cells, influencing motility. This study reveals somatostatin receptor subtype-2 is key in modulating cholecystokinin-induced contractions.
Area of Science:
- Gastroenterology
- Pharmacology
- Cell Biology
Background:
- Somatostatin is known to affect colonic motility across species.
- Limited cellular data exist on somatostatin's effects on human colon motility.
Purpose of the Study:
- To investigate the direct cellular effects of somatostatin on human circular colonic smooth muscle cells.
- To determine if somatostatin's actions are mediated directly or neurally.
Main Methods:
- Human circular colonic smooth muscle cells were isolated via enzymatic digestion.
- Cells were treated with somatostatin analogs (somatostatin-14, somatostatin-28, SMS 201-995) and cholecystokinin.
- Inhibition of cholecystokinin-mediated contraction was assessed.
Main Results:
- Somatostatin analogs alone induced minor contractions.
- Somatostatin analogs inhibited cholecystokinin-mediated contractions in a dose-dependent manner, particularly in the presence of antiproteases.
- Similar half-maximal effective concentrations (EC50) were observed for the somatostatin analogs.
Conclusions:
- Somatostatin directly acts on human circular colonic smooth muscle cells via specific receptors.
- The somatostatin analog SMS 201-995 demonstrated high affinity for inhibiting cholecystokinin-induced contractions.
- Evidence suggests the presence of somatostatin receptor subtype-2 on human circular colonic smooth muscle cells.
Related Concept Videos
08:30Preparation and Utilization of Freshly Isolated Human Detrusor Smooth Muscle Cells for Characterization of 9-Phenanthrol-Sensitive Cation Currents
07:17Measuring Proliferation of Vascular Smooth Muscle Cells Using Click Chemistry
07:56Contractility Measurements of Human Uterine Smooth Muscle to Aid Drug Development
08:24Isolation of Murine Coronary Vascular Smooth Muscle Cells
08:02Isolation of Pulmonary Artery Smooth Muscle Cells from Neonatal Mice
08:06Isolation of Human Umbilical Arterial Smooth Muscle Cells (HUASMC)