PROTEIN-PRODUCTION AND RELEASE BY DISPERSED RAT SUB-MANDIBULAR GLAND-CELLS INVITRO AFTER ADRENERGIC-STIMULATION

Enzymatically dispersed cell aggregates were prepared from rat submandibular glands. Cells were responsive to .alpha.- and .beta.-adrenergic agonists, as measured by net K+ release and radiolabeled protein secretion, respectively. Protein production by submandibular gland cells was constant during the 90 min experimental period. Specific agonist and antagonist experiments demonstrated that .alpha.- and .beta.-adrenergic receptor stimulation were required for maximum secretion of newly synthesized protein. Proteins were radiolabeled with [35S]methionine and soluble cell and secreted proteins examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autofluorography. A broad size range of newly synthesized proteins was detected. Adrenergic stimulation (1-epinephrine) specifically increased the secretion of certain radiolabeled proteins and, in addition, resulted in cellular and secreted proteins with electrophoretic characteristics distinct from that of control preparations.