Specific immunoelectronmicroscopic localization of vasopressin and oxytocin in the neurohypophysis of the rat
An immunoelectronmicroscopic method for the specific localization of neurohypophyseal hormones was developed in neurohypophyses of Wistar and Brattleboro rats, the latter strain being homozygous for diabetes insipidus. If the proper precautions were omitted, a marked cross reactivity between antivasopressin and antioxytocin preparations was found. Cross reaction of an antivasopressin plasma with oxytocin, at a dilution of less than 1∶1600, resulted in electron density of all granules within neurosecretory fibres of the Brattleboro and Wistar neurohypophyses. However, this cross reactivity could be eliminated either by sufficient dilution of the antiplasma, or by its purification. Purification of the antibodies was performed by absorption to agarose beads coated with the cross reacting component. Upon incubation with antivasopressin (diluted unpurified 1∶1600 or purified 1∶80) and unpurified antioxytocin (1∶400) plasma, sections of a Wistar neurohypophysis revealed two types of neurosecretory fibres, containing either electron dense or lucent granules. Oxytocin and vasopressin containing neurosecretory fibres were found as clusters in the neurohypophysis. The specificity of both unpurified antivasopressin (1∶1600) and antioxytocin (1∶400) plasma was confirmed on serial sections of a Wistar neurohypophysis, alternately incubated with the solutions of the two antibodies.
These data prove that the one-cell-one-hormone hypothesis holds true for the hypothalamic-neurohypophyseal system.
Key wordsVasopressin Oxytocin Neurohypophysis Specificity Immunoelectronmicroscopy
Unable to display preview. Download preview PDF.
- Aspeslagh, M.-R., Vandesande, F., Dierickx, K.: Electron microscopic immunocytochemical demonstration of separate neurophysin-vasopressinergic and neurophysin-oxytocinergic nerve fibres in the neural lobe of the rat hypophysis. Cell Tiss. Res. 171, 31–37 (1976)Google Scholar
- Leclerc, R., Pelletier, G.: Electron microscope immunohistochemical localization of vasopressin in the hypothalamus and neurohypophysis of the normal and Brattleboro rat. Amer. J. Anat. 140, 583–587 (1974)Google Scholar
- Luft, J.H.: Improvements in epoxy resin embedding methods. J. biophys. biochem. Cytol. 9, 409–413 (1961)Google Scholar
- Miller, M., Moses, A.M.: Radioimmunoassay of vasopressin with a comparison of immunological and biological activity in the rat posterior pituitary. Endocrinology 84, 557–562 (1969)Google Scholar
- Reynolds, E.S.: The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963)Google Scholar
- Silverman, A.J., Zimmerman, E.A.: Ultrastructural immunocytochemical localization of neurophysin and vasopressin in the median eminence and posterior pituitary of the guinea pig. Cell Tiss. Res. 159, 291–301 (1975)Google Scholar
- Sokol, H.W., Valtin, H.: Evidence for the synthesis of oxytocin and vasopressin in separate neurons. Nature (Lond.) 214, 314–316 (1967)Google Scholar
- Sokol, H.W., Zimmerman, E.A., Sawyer, W.H., Robinson, A.G.: The hypothalamic-neurohypophyseal system of the rat: localization and quantitation of neurophysin by light microscopic immunocytochemistry in normal rats and in Brattleboro rats deficient in vasopressin and a neurophysin. Endocrinology 98, 1176–1188 (1976)Google Scholar
- Sternberger, E.A.: Immunocytochemistry. Foundation of Immunology Series. Englewood Cliffs, New Jersey: Prentice-Hall 1974Google Scholar
- Swaab, D.F., Boer, G.J., Nolten, J.W.L.: The hypothalamo-neurohypophyseal system (HNS) of the Brattleboro rat. Acta endocr. (Kbh.), Suppl. 177, 80 (1973)Google Scholar
- Swaab, D.F., Nijveldt, F., Pool, C.W.: Distribution of oxytocin and vasopressin in the rat supraoptic and paraventricular nucleus. J. Endocr. 67, 461–462 (1975b)Google Scholar
- Swaab, D.F., Pool, C.W.: Specificity of oxytocin and vasopressin immunofluorescence. J. Endocr. 66, 263–272 (1975)Google Scholar
- Swaab, D.F., Pool, C.W., Nijveldt, F.: Immunofluorescence of vasopressin and oxytocin in the rat hypothalamo-neurohypophyseal system. J. Neural Transm. 36, 195–215 (1975a)Google Scholar
- Vandesande, F., Dierickx, K.: Identification of the vasopressin producing and of the oxytocin producing neurons in the hypothalamic magnocellular neurosecretory system of the rat. Cell Tiss. Res. 164, 153–162 (1975)Google Scholar
- Van Leeuwen, F.W., Swaab, D.F., Romijn, H.J.: Light and electron microscopic immunolocalization of oxytocin and vasopressin in rats. In: Immunoenzymatic Techniques, INSERM Symp. No. 2 (G. Feldmann, P. Druet, J. Bignon and S. Avrameas, eds.). Amsterdam-Oxford: North-Holland Publishing Company 1976Google Scholar