Bombesin-like immunoreactivity in bovine adrenal medulla.
The presence of immunoreactive (ir)-bombesin in bovine adrenal medulla, isolated adrenal chromaffin cells and subcellular fractions of the adrenal medulla was demonstrated using a specific antibody to the synthetic peptide. High levels of ir-bombesin were detected in acid (HCl) extracts of the adrenal tissue (27 pmol/g) and isolated cells (0.35 pmol per 10(6) cells). Subpopulations of adrenal chromaffin cells were also obtained by centrifugation of the original cell preparation through a stepwise bovine serum albumin gradient (cell layers I, II and III). The highest concentration of ir-bombesin (0.77 pmol/10(6) cells) was found in a cell population (cell layer I) enriched in noradrenaline (adrenaline/noradrenaline ratio of 0.6). At the subcellular level, ir-bombesin was mainly concentrated in the secretory granules (0.61 pmol/mg protein) along with catecholamines (1097 nmol/mg protein), but a relatively high concentration of ir-bombesin (0.26 pmol/mg protein) was also found in the microsomal fraction. Isolation and high performance liquid chromatography (HPLC) analysis of adrenomedullary ir-bombesin revealed the presence of four molecular forms, one of them corresponding to gastrin releasing peptide (GRP), another one (major peak) eluting closely to synthetic neuromedin B and another one coeluting with GRP-(18-27). HPLC analysis of the molecular forms of ir-bombesin in the microsomes and secretory granules indicated that GRP- and neuromedin B-like materials can be generated between the two fractions.
D000109:Acetylcholine / Q000378:metabolism; D000313:Adrenal Medulla / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D001839:Bombesin / Q000302:isolation & purification / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism; D002417:Cattle; D002838:Chromaffin System / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003594:Cytoplasmic Granules / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000378:metabolism; D019886:Gastrin-Releasing Peptide; D066298:In Vitro Techniques; D008861:Microsomes / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D011863:Radioimmunoassay; D013347:Subcellular Fractions / Q000378:metabolism
D002395:Catecholamines; D010455:Peptides; D004743:Enkephalin, Leucine; D019886:Gastrin-Releasing Peptide; D000109:Acetylcholine; D001839:Bombesin