Three‐dimensional architecture and distribution of collagen components in the goat hypophysis

Abstract

The three-dimensional architecture of collagen fibrils in the connective tissue framework and the distribution of collagen types in the goat hypophysis were studied by the cell maceration method in combination with scanning electron microscopy (SEM) and immunohistochemistry. The pars distalis of the adenohypophysis consisted of many cell clusters. SEM revealed that the wall of cell clusters appeared as various-sized flat bundles of collagen fibrils woven in a basket-like configuration. In the pars tuberalis, the aggregates of collagen fibrils were denser and bundles thicker compared to the pars distalis. The density of collagen fibrils changed from the pars tuberalis to pars distalis without a distinct border. The collagen framework in the pars intermedia was mainly divided into three parts, the dorsal region with large hollows, the middle region, and the ventral sheet facing the cavum hypophysis. In the lobus nervosus of the neurohypophysis, the collagen network exhibited a sponge-like appearance at low magnification. Collagen fibrils of various sizes consisted of loose wavy bundles distributed around the cavities. Immunohistochemistry revealed types I, III, IV, V, and VI collagen throughout the hypophysis. It is concluded that to maintain structural and functional integration, the components of collagen are in different configurations throughout the regions of the goat hypophysis. Anat Rec Part A 277A: 275-286, 2004.

In situ hybridization reveals that type I and III collagens are produced by pericytes in the anterior pituitary gland of rats

“…Type I and III collagens have previously been found to be located mainly near blood vessels in the rat anterior pituitary gland (Kaidzu et al 2000). Using scanning electron microscopy, Nishimura et al (2004) have revealed that collagen bundles are abundant on the surface of glandular cell clusters and sinusoids in the goat pituitary gland; however, immunohistochemistry and electron-microscopic observation could not identify the collagen-producing cells in the gland. Our results indicate that in situ hybridization is suitable for the detection of collagen-producing cells in vivo.…”

Immunohistochemical and scanning electron microscopic comparison of the collagen network constructions between pig, goat and chicken livers

“…Ohtani (1988) reported the architecture of the normal liver in humans and rats and demonstrated that the arrangement of the collagen fibrils was essentially the same, except for the architecture of the capsule. We have previously reported the three‐dimensional collagen architecture in the pars distalis of the goat adenohypophysis (Nishimura et al. 2004).…”

Lack of collagen VI promotes neurodegeneration by impairing autophagy and inducing apoptosis during aging

“…In the CNS, collagen VI was first described among the ECM molecules detected in the proper glia limitans [ 5 ]. Initial immunohistochemical studies showed the presence of collagen VI mainly in the connective compartments of the CNS [ 6 ]. More recently, a study demonstrated increased hippocampal Col6a1 expression in a transgenic mouse model for familial Alzheimer's disease, as well as in patients with Alzheimer's disease, and suggested a neuroprotective role for collagen VI against the toxicity of amyloid-Δ peptides [ 7 ].…”