Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Guinea-pig ileum. Contractions due to 5-HT (HT), nicotine (N) and histamine (H). Doses μg. in 2 ml. bath. Above with morphine (1 μg./ml.). Effects on D receptors unchanged by atropine (0.1 μg./ml.) from 18 min. onwards. Dose-ratio= 1.3. Below after dibenzyline (0.1 μg./ml. for 30 min.). Effects on M receptors inhibited utropine (0.1 μg./ml.) from 38 min. onwards. Dose-ratio > 300 for 5-HT.
