“…The continuous-infusion method (Waterlow et al 1978 a) requires several hours to reach a plateau of constant labelling, even in the rat, and has largely been replaced by giving a flooding dose of tracer amino acid, which produces uniform labelling of free amino acid over 10-20 min (Kean, 1959;Scornik & Botbol, 1976;McNurlan, Tomkins & Garlick, 1979;Garlick, McNurlan & Preedy, 1980 c). The method is particularly useful for rapidly turning over tissues such as gut mucosa (McNurlan, Pain & Garlick, 1980) and pancreas (Simon, Zebrowska, Bergner & Munchmeyer, 1983). Because of the short time scale, the method measures the synthesis of both fixed and secreted proteins.…”