Is immunohistochemical analysis of oestrogen and progesterone receptors in endometrial carcinoma superior to the radioligand binding assay?

The aim of this study was to evaluate tissue and steroid receptor heterogeneity in endometrial carcinoma specimens as a possible source of discordance between biochemically assayed receptor status and response to endocrine treatment. For this purpose the oestrogen receptor (OR) and progesterone receptor (PR) levels in specimens from 16 endometrial carcinoma patients were analysed on adjacent tissue sections using both a radiochemical and an immunohistochemical assay. With immunohistochemical receptor analysis extensive tissue and tumour cell receptor heterogeneity was observed.

Quantification of oestrogen receptors in breast cancer: radiochemical assay on cytosols and cryostat sections compared with semiquantitative immunocytochemical analysis.

A radiochemical oestrogen receptor assay on cytosol was correlated with a radiochemical and an immunohistochemical oestrogen receptor assay using cryostat sections from 50 breast cancer specimens. Oestrogen receptors were reliably quantitated in 6 micron cryostat sections with Scatchard analysis using radiolabelled oestradiol, and a good quantitative and qualitative relation with cytosol oestrogen receptor assay was found. Parallel sections were used for routine histological tissue verification and for direct comparison with immunohistochemistry for oestrogen receptor.

Progesterone receptor quantification with radiolabeled promegestone (R 5020) in frozen sections of endometrium and breast cancer tissue.

A technique for the determination of the progesterone receptor content at sections was developed. Series of coverglass-mounted unfixed frozen sections were incubated with [3H]R5020 only, to determine total binding, or with excess unlabeled R5020, to determine non-specific binding. Ligand binding in the tissue sections was measured by liquid scintillation counting after repeated washing of the coverslips.

Cholinergic receptors in the upper respiratory system of the rat.

Radioligand receptor binding might give more detailed information on the innervation pattern of the nasal mucosa and the character of the various neuroreceptors involved. With respect to the cholinergic receptors, this technique reveals that specific binding of tritiated I-quinuclidinyl benzilate to rat nasal mucosa homogenates occurs to a homogeneous class of binding sites, with a dissociation constant of 0.06 +/- 0.

Muscarinic receptors in rat nasal mucosa are predominantly of the low affinity agonist type.

Specific [3H]l-quinuclidinyl benzilate binding to rat nasal mucosa homogenates occurs to a homogeneous class of binding sites with Kd = 60 +/- 2 10(-12) M and Bmax = 8.1 +/- 2 pmol/g tissue. Binding is stereoselectively inhibited by benzetimide enantiomers.