1. The Pituitary Gland of the Roach <em> Leuciscus rutilus</em>. III. The Pars Intermedia and Its Innervation.
- Author
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Båge, Gerirud, Ekengren, Bo, Fernholm, Bo, and Fridberg, Gunnar
- Subjects
ENDOCRINE glands ,ELECTRON microscopy ,CELLS ,NEURONS ,AXONS ,BASAL lamina - Abstract
Two endocrine cell types, PbH + and PAS + cells, were recognized in the pars intermedia (PI) of the roach. Leuciscus rutilus, by light and electron microscopy. They can be distinguished by the appearance of their secretory granules. The PAS + cells stain with toluidine blue in semithin sections as opposed to the PbH + cells. After 5 days' treatment with metopirone the PhH + cells are highly activated whereas the PAS + cells show no response. The PbH + cells are assumed to produce MSH. In roaches adapted to diluted sea water (10 ‰) the transfer to fresh water for 1- -1 ½ hours or reset-pine injections for the same period had no notable effect on neither cell type. Three kinds of axons innervate the P1. Two of these, which have granules averaging 111 nm arid 151 nm in diameter. originate in the nucleus preopticus (NPO). The third type of axons has granules of an average Size of 74 nm and is probably aminergic. The glia cells in this part of the neurohypophysis (NH) are granular pituicytes, which are innervated by all three axon types. The border between the NH and the PT is composed of a double basement membrane from which a network extends into the NH. This network, the basement membrane and the capillaries are the main sites for the terminations of the axons although nerve fibers also invade the endocrine tissue. Only axon type 3 was observed to synapse frequently with the PbH + cells. [ABSTRACT FROM AUTHOR]
- Published
- 1975