Microvascular density, microvascular surface area and endocrine cell volume in pituitary transplants to the fourth ventricle of adult rats.
Pituitary gland endocrine tissue was transplanted to the fourth ventricle of the brain of adult rats. The grafts were left in place for eight to ten weeks. One micron thick Epon sections were cut for microscopical and morphometrical analysis. The microvascular length density, the microvascular surface area density and the volume weighted mean pituitary cell volume were measured. The transplants were connected to the recipient brains through a few rather large vessels vessels either from the arachnoidea or the choroid plexus. Neuronal connections were never established. The microvascular length and surface area densities were significantly increased in the grafts, whereas the weighted mean cell volume was reduced. The results indicate that pituitary tissue can be transplanted to the fourth ventricle of the brain and the blood supply reestablished. The increased vascular densities are due to lower cell volume and probably also to cell loss and not to proliferation or angiogenesis. The reduced pituitary cell volume may be the result of missing trophic factors which normally are secreted to the pituitary in the sella turcica.
Laursen
H
H
Institute of Neuropathology, University of Copenhagen, Denmark.
Christensen
L
L
D000818:Animals; D002552:Cerebral Ventricles / Q000098:blood supply*; D005260:Female; D008297:Male; D008833:Microcirculation / Q000166:cytology*; D009389:Neovascularization, Pathologic; D010902:Pituitary Gland / Q000098:blood supply* / Q000637:transplantation*; D051381:Rats; D011919:Rats, Inbred Strains; D016042:Transplantation, Heterotopic