Localization of adenosine o',5'-monophosphate in mouse epidermis by immunofluorescence

Adenylate cyclase activity during growth and maturation of keratinocytes: comparison of two methods of study

The adenylate cyclase activity of primary cultures of guinea-pig ear keratinocytes was studied at different times by challenge with various agonists after labelling of ATP by exposure of the cells to [3H]-adenine. The [3H]-cAMP (cyclic adenosine-3',5-monophosphate) formed was assayed by scintillation counting. In other experiments, cells were exposed to the equivalent amount of unlabelled adenine, challenged and cAMP was then assayed by radioimmunoassay. These absolute amounts were compared to [3H]-cAMP levels expressed as percentage conversion of [3H]-ATP. Comparison of the two methods suggested that the use of the prelabelling method would result in underestimation of cAMP formed. It was found that the response of the enzyme to different agonists changed with the length of time of the cells in culture.

Immunohistochemical localization of cyclic nucleotides in guinea pig lip

The cellular localization of cAMP and cGMP in the guinea pig lip was investigated with an indirect immunofluorescence technique. cAMP was distributed both in cell membranes and cytoplasmic elements with coarse and granular intranuclear fluorescence, while cGMP was localized in nuclear sites including nuclear membranes as well as cell membranes and cytoplasm. In the basal portion, both cAMP and cGMP fluorescence was weaker in cytoplasm and cell membranes than seen in the upper portion.

Electron microscopic cytochemical demonstration of adenyl cyclase activity in psoriatic epidermis

Isoproterenol and sodium fluoride stimulated adenyl cyclase activity was detected in epidermal tissue from 2 patients with untreated psoriasis by an electron microscopic cytochemical technique. Adenyl cyclase activity was present on the outer surface of the cell membranes, predominantly in the basal cells and in the 4-5 lower Malpighian cell layers, while the superficial layers, stratum granulosum and stratum corneum showed no activity. The precipitates (lead-PPi complexes) after isoproterenol stimulation were larger and fewer in number than those seen after sodium fluoride stimulation. Isoproterenol stimulation was abolished by propranolol. Neither the uninvolved epidermis from the 2 patients with psoriasis nor the normal skin from 2 volunteer individuals showed any difference from the psoriatic epidermis.