Effects of neuronal polypeptides on intestinal smooth muscle; a comparison with non-adrenergic, non-cholinergic nerve stimulation and ATP

摘要: Abstract Substance P, somatostatin, enkephalin and vasoactive intestinal polypeptide (VIP) did not mimic the inhibitory responses to non-adrenergic, non-cholinergic nerve stimulation. P (0.1–10 μg/ml) always caused contraction, somatostatin were inactive, while VIP (0.01–1 μ/ml) produced very slow relaxation, taking about 4 min reach a maximum after latency of 60 sec. Low concentrations neurotensin (1–10 ng/mg) but higher (50–1000 ng/ml) it biphasic response which consisted an initial contraction followed by relaxation. In high tone preparations, relaxation nerve-mediated response, approximately 43 maximum, long 15 contrast, ATP (0.1–50 mimicked closely rapid stimulation in all whether was low, medium or high. The time for sec 1 Indomethacin (3.4–34 unmask any peptides. It is concluded that remains most likely substance be transmitter released from nerves supplying smooth muscle taenia coli.