Identification of luteinizing hormone-like proteins in the ovine pineal gland
| Autor: | J. Honing, F.H. Jong, H. P. J. M. Noteborn, I. Ebels, C. A. Salemink |
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| Rok vydání: | 1992 |
| Předmět: |
Male
medicine.medical_specialty Radioimmunoassay Biology Cross Reactions High-performance liquid chromatography Pineal Gland Pineal gland Endocrinology Internal medicine Protein purification medicine Animals Polyacrylamide gel electrophoresis Chromatography High Pressure Liquid Sheep Leydig cell Dextrans Luteinizing Hormone Chromatography Ion Exchange Molecular Weight medicine.anatomical_structure Biochemistry Sephadex Pituitary Gland Chromatography Gel Biological Assay Electrophoresis Polyacrylamide Gel Female Follicle Stimulating Hormone Luteinizing hormone Gels Endocrine gland |
| Zdroj: | Journal of pineal research. 12(3) |
| ISSN: | 0742-3098 |
| Popis: | A chemical analysis was instigated to investigate the identity of the luteinizing hormone (LH)-like immunoactivity present in ovine pineal protein homogenates. Isolation of pineal LH-like material was accomplished using a 0.1 M ammonium sulphate (pH 4.0) extraction followed by anion-exchange chromatography. The resulting 3.0 M ammonium sulphate precipitate containing 70% of the LH-like immunoactivity was refractionated by cation-exchange and Sephadex G-100 chromatography. Analysis of the pattern of recovered LH-like immunoactivity in the Sephadex G-100 eluate indicated the presence of molecular weight (MW) less than 60,000 besides MW 21,000 species of LH-like proteins. Bioactivity was tested in the rat Leydig cell steroidogenesis assay. In terms of steroid production, the activity was associated with the MW 21,000 LH-like proteins only. Further purification by CM-Sephadex chromatography and gel permeation HPLC was conducted in order to determine whether the physicochemical properties of pineal LH-like material represented endogenous LH, synthesized and released by the ovine pituitary. It is concluded by a variety of means, including polyacrylamide gel electrophoresis, and amino acid and carbohydrate analyses, that at least two molecular forms of immunoactive LH-like proteins occur in ovine pineal tissue. The MW 21,000 forms showed much similarity with ovine adenohypophyseal LH or with a complex mixture of its subunits. These observations contribute to the understanding of endocrine-endocrine transducing events that may occur in this organ. |
| Databáze: | OpenAIRE |
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