ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
The distribution and cellular localization of the glycoprotein laminin were investigated by light and electron microscopic immunocytochemistry in the adult murine pituitary gland. Immunoblots confirmed that laminin was the only protein in the pituitary gland of the adult male mouse to react with antilaminin serum. Laminin immunoreactivity was demonstrated at the light microscopic level simultaneously with that of β-follicle stimulating hormone (β-FSH) and β-luteinizing hormone (β-LH). In addition to its distribution is basal laminae, laminin immunoreactivity was coincidently expressed in gonadotrophs with the immunoreactivities of β-FSH and β-LH. Electron microscopic immunocytochemistry was employed on aldehyde-fixed sections embedded in L.R. White. Sites of binding of primary antisera to laminin were identified with affinity-purified secondary antisera directly coupled to 20 nm particles of colloidal gold. Three antisera recognizing laminin were compared and found to result in an identical pattern of immunoreactivity. Laminin was found extracellulary only in formed basal laminae in all three lobes of the pituitary and was not found in extracellular matrices of connective tissue. Laminin immunoreactivity was also found intracellularly in gonadotrophs but in none of the other endocrine or non-endocrine cells of the anterior lobe. Within gonadotrophs, only secretory granules were labeled. The majority, but not all, secretory granules were labeled in each of the gonadotrophs examined, and the proportion of granules labeled with laminin could not be increased by doubling the concentration of anti-laminin serum. Laminin immunocreactivity segregated with the subset of secretory granules containing β-FSH. In contrast, laminin immunoreactivity was absent in the smaller subset of secretory granules that contain serotonin. No secretory granules were labeled within the endocrine cells of the intermediate lobe, nor within secretory granules of neural elements in the posterior lobe.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1092260409
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