Computerized histomorphometric study of the splenic collagen polymorphism: A control‐tissue for polarization microscopy

Abstract

Previous articles have pointed out the presence of type III collagen within the extracellular structure of the parenchymatous organs. This study aimed to quantitatively characterize the collagen polymorphism at the capsule and parenchymal trabeculae of the largest lymphoid organ of the body i.e., the spleen, in mouse, rat, and rabbit models. Following a Picrosirius Red-Polarization procedure and computer assisted image analysis of paraffin sections, the results showed (1) a predominant and significantly higher amount of type III collagen in the trabeculae area compared to the capsule area in the three species, (2) no statistical difference among the three species concerning the parenchymal collagen polymorphism or the type I/type III collagen ratio, (3) a heterogeneous type I/type III collagen ratio varying from 0.86 (mouse) to 6.62 (rabbit) in the fibromuscular capsule region. A qualitative analysis corroborated these histomorphometric results. In conclusion, the spleen may be used as (1) a control tissue to qualitatively visualize type I and III collagen under polarization microscopy and to validate the quality of PSR staining (2) an aid to accurately calibrate the angle of polarization before quantitative measurements of type I and type III collagen. Among the studied species, the rabbit spleen appeared to be the most appropriate control tissue as it showed the highest amount of type I collagen in the capsule and a similarly high amount of type III collagen in the parenchymal trabeculae.

Structural and Ultrastructural Characteristics of Bone-Tendon Junction of the Calcaneal Tendon of Adult and Elderly Wistar Rats

“…As well as in our study other authors has used this method in various tissues to quantify collagen, for example Singh and colleagues (2012) [ 52 ] in their study about role of connective tissue stroma on biological behavior of odontogenic cysts, Geary and colleagues (2015) [ 53 ] in study of tendon repair, Manjunatha and colleagues (2015) [ 54 ] in oral squamous cell carcinoma, Alves and colleagues (2015) [ 55 ] in a study of the splenic collagen polymorphism, and many others.…”

Reproductive age-associated fibrosis in the stroma of the mammalian ovary

“…Collagen is the main structural protein family of connective tissue and provides structural integrity to tissues in addition to regulating their function through signaling. Changes in the collagen matrix of soft tissues mostly affect the fibrillar type I and III collagens, and type I collagen is the most ubiquitously expressed ECM molecule within the mouse ovary (Alves, et al 2015, Berkholtz, et al 2006). Fibrosis occurs when normal tissue remodeling and wound-healing responses are not properly regulated; this can lead to aberrant tissue architecture and thereby compromised organ function (Wynn and Ramalingam 2012).…”

Devising tissue ingrowth metrics: a contribution to the computational characterization of engineered soft tissue healing

“…Lymphoid organs are known to be composed of collagen type III in their parenchyma and of collagen type I in the fibrous capsule. We verified those biologic data in spleen and were subsequently able to use PR-stained rabbit spleen as a control tissue for collagen polymorphism investigation under polarized light [30].…”

“…Results were expressed as a ratio of collagen type I and type III surface areas. Under CPM, a section of spleen from a rabbit, rich in parenchymal reticulin (collagen type III) and collagen type I (spleen capsule) was prepared under the same conditions and used as positive control to accurately set the angle of the microscope polarizer (the analyzer filter being fixed) before measurement of the collagen types I and III surface areas [30].…”