The Regulation Function Of Calcitonin Gene Related Peptide On Rat Gastric Smooth Muscle

Objective: To explore the calcitonin gene related peptide (CGRP) and its receptor antagonist (CGRP 8-37) regulation function of gastric smooth muscle, by studying CGRP on the role of cells in vitro.Methods: In the study, surgical methods was used to take SD rat stomach tissue.Using tissue culture methods, we isolated and cultured the SD rat gastric smooth muscle cells in vitro. Stomach muscle cells were culrured in DMEM supplemented with 20% FBS. Immunocytochemical stain with specific smooth muscle a-actin antibody was applied to identify the primary culture cells. Experiment were divided CGRP (10-7-10-9M) group, CGRP 8-37 group and control group. The length of 50 freshly dispersed gastric smooth muscle cells was measured by micrometry before and after giving CGRP; By means of the fluorescent tracer Fura-2/AM, [Ca2+]were tested to show how CGRP affect gastric smooth muscle cells; Celltiter-Glo(?) kit to detect the contents of ATP in the cells.Results: Surgical method and enzymatic method can be extracted cells,the cells used in the proposed shorter enzymatic method, but a lot of impurities, attached method although a relatively long time, but the purity of the cells is relatively high.SD rat gastric smooth muscle cells were dispersed successfully. Freshly isolated cells were spindle-shaped or polygon-shaped with centrally located nuclei. The positive effect by immunocytochemical stain was irregular shape with brown plasm and blue nuclei. It turned out that almost all cells cultured have those characters. CGRP in various concentration can reduce gastric smooth muscle free [Ca2+], and strengthened with the increase of the dose within limits. CGRP effect after compared with control group can reduce the ATP content of smooth muscle cells. With the increase of drug concentration, the change of ATP content also increased (P < 0.05).Conclusion: Rat gastric smooth muscle cells could be dispersed successfully by explant method. After second adhesion cells could be purified and culture in DMEM. The experiment shows that CGRP can relax the gastric smooth muscle cells, reduce the concentration of intracellular Ca2+ and ATP content, it seems that Ca2+ concentration may be involved in the mechanism of the relaxation of smooth muscle cells; CGRP may through changing the kinetic energy of the gastric smooth muscle cells inhibit gastric smooth muscle movement.