Table 1.

Effects of ATP on segments of gastrointestinal tract

Animal	Gut segment	ATP (g/ml)	Response
Guinea-pig	stomach	10−5–10−4	—
	ileum	10−6–10−4	—(low conc.)+(high conc.)
	colon	5 × 10−6–2 × 10−5	—
Rabbit	stomach	10−5-10−4	—(low conc.)+(high conc.)
	ileum	10−6-10−4	—
	colon	10−5-10−4	—
Rat	stomach	2 × 10−6–2 × 10−5	— followed by +
	duodenum	2 × 10−6–10−5	—
	colon	2 × 10−5	—
Mouse	ileum	5 × 10−6–2 × 10−5	—
	colon	5 × 10−6–5 × 10−5	—(low conc.)+(high conc.)
Toad	stomach	5 × 10−7–5 × 10−4	—, +, or + followed by −

+ = contraction during application of ATP.

− = relaxation or inhibition of spontaneous movements.