How does one demonstrate cytoprotection in man?

The term 'cytoprotection' is discussed. Attempts to demonstrate cytoprotection in human subjects are described and the value and limitations of such human experimental models are explored. Recent trials of prostaglandins in the prevention of gastric damage in arthritic patients are reported. It is concluded that additional clinical trials are needed, not only in peptic ulcer disease but in drug induced gastropathy and stress ulcer. To convincingly demonstrate cytoprotection, direct comparisons with H2 blockers are needed or studies using prostaglandins at dose levels which clearly do not inhibit gastric acid secretion.