Gastric mucosal blood flow is regulated by neural, hormonal, and locally active influences. Which of the following statements correctly characterizes gastric blood flow?

c. Stimulants that increase acid secretion increase mucosal blood flow

d. In humans, prostaglandins increase mucosal blood flow at doses that inhibit gastric acid secretion

Because the gastric mucosa is metabolically highly active, control of gastric mucosal blood flow is of great physiologic significance. Almost all stimuli that increase acid secretion also increase gastric blood flow. A large number of gastrointestinal hormones stimulate gastric blood flow, most because of their ability to increase acid secretion. Thus, gastrin is a potent stimulant of blood flow, in proportion to its ability to increase acid secretion. Vagal nerve stimulation has the net effect of increasing mucosal and total gastric blood flow; sympathetic nerve stimulation is accompanied by opposite effects.

 Prostaglandins are important endogenous regulators of gastric blood flow. Prostaglandins of the E class increase blood flow at doses that suppress acid secretion. Inhibition of cyclo-oxygenase activity by indomethacin causes a reduction in resting gastric blood flow.