Effect of substance P and its natural analogues on gastric emptying of the conscious rat

1 Substance P and its natural analogues were tested for their effect on gastric emptying in the rat. 2 Substance P and kassinin were virtually inactive even at the maximum dose tests. 3 The other tachykinins significantly delayed gastric emptying their effect being quite remarkable with 100 micrograms/kg. The lowest doses (30 microgram/kg) caused a slight and non-significant increase in emptying rate. 4 The effect on gastric emptying was most probably correlated with a spasmogenic effect on the gastroduodenal junction, as pointed out in previous work.