Carbon Dioxide → Serotonin

Participants

Reaction Steps

For the experiment, helical segments of the basilar artery of pigs were used which were isolated from pig brains supplied by a slaughterhouse. Each strip was fixed in an organ bath consisting of 10 ml of a modified Tyrode solution such that the tissue was under a tension of 10 mN. Tyrode solution is an aqueous solution containing per liter 150.0 mmol of NaCl, 4.0 mmol of KCl, 1.8 mmol of CaCl2.2H2O, 1.1 mmol of MgCl2.6H2O, 25.0 mmol NaHCO3, 0.3 mmol of NaH2PO4.H2O and 11.1 mmol of glucose. The solution was modified by adding 10-8 mol/l of indomethacin, 10-7 mol/l of atropine and 10-7 mol/l of propanolol and adjusted to pH=7.4. The bath was aerated with a mixture of 95% O2 and 5% CO2. After an equilibration phase of 1 hour a contraction of the tissue was produced twice, in each case by addition of serotonin at a concentration of 10-5 mol/l and the preparation was subsequently washed out. The contraction effect was then measured with increasing serotonin concentration and a cumulative concentration effect curve for serotonin was drawn up. A cumulative concentration effect curve was drawn up for the test substance on the same preparation (after washing out again).

Provenance & Evidence