Cytochemical demonstration of rat liver adenylylcyclase attempts of methodological improvements.

: A new method has been applied using strontium as trapping agent in place of lead and incubation at pH 8.9 of liver samples taken from rats treated in vivo with isoprenaline (IPR). Ultrastructural observations have revealed two different staining patterns: one, found in samples incubated in the standard medium and selectively localized on hepatic plasma membrane, is considered specific; the other, observed in vitro assays to determine enzymatic specificity is probably of non-enzymatic nature. The latter findings represents a difficult point in the evaluation of this technique.