Smooth Muscle Excitatory Substances from Remak Nerve of the Chicken and a Comparison of Their Pharmacological and Chemical Properties with Substance P

[摘要] References(18)Cited-By(4)Active substances extracted from the Remak nerve of the chicken were subjected to chromatographic and electrophoretic separation followed by bioassay of contracting activities on the longitudinal muscle of the guinea-pig ileum (LMGPI) and on the isolated whole chick rectum (WCR). Gel filtration profiles on a Sephadex G-50 column showed two peaks of LMGPI-contracting activity and of WCR-contracting activity. No difference was seen in the enzymatic destruction between the LMGPI-contracting activity and substance P. Their similarities were also indicated by the parallelism of their elution curves in the gel chromatography on Sephadex G-25, their equal stability in acid solutions, and comparable antagonism and inhibition of the contractile effects on LMGPI by substance P antagonists and after desensitization of substance P receptors. Ion exchange chromatography revealed the existence of two main substances responsible for the LMGPI-contracting activity. One of them eluted at the same position as that for substance P, but differed in immunoreactivity and electrophoretic mobility from substance P. The WCR-contracting activity differed from the LMGPI-contracting activity in that it was pepsin-resistant and carboxypeptidase A-susceptible, and it eluted at a different position during ion exchange chromatography. It seems likely that the LMGPI-contracting activity in the extracts is attributed to a substance P-family of peptides, but the WCR-contracting activity is due to another substance of a peptide nature.

[学科分类] 药理学