The Histological Components of the Phoniatrical Body-Cover Model in Minipigs of Different Ages

Abstract

Pigs are models in human phoniatry. However, features of maturation and ageing have not been considered with regard to the so-called body-cover model in this species. Therefore, the glottis of “young” (2–3 months; n = 6) and “old” (4–7 years; n = 6) minipigs was investigated. Their cranial (CraF) and caudal (CauF) vocal folds were histomorphometrically and stratigraphically analysed with emphasis on their amounts of collagen structures and elastic fibres. A dense subepithelial layer (SEL) was a distinct feature of CraF and CauF of both age groups; it was spread upon the underlying loose, flexible “cover” like a fibro-elastic membrane. The “cover” was characterised by the so-called superficial layer (SL), which was distinctly loose in the “young” minipigs, but had a much denser texture in the “old” minipigs. Here, the SL was dominated by elastic fibres in the CraF, but was of mixed qualities (collagenous and elastic) in the CauF. The structural requirements for the SL’s function as a loose “cover” were thus met only in the “young” animals. A clearly demarcated intermediate layer (IL)—characterised by high amounts of elastic fibres (as in humans)—was only found in the CraF of the “young” animals. In the “old” animals, it had lost its demarcation. In the depth of the CraF of the “old” animals, many thick collagen fibre bundles were detected in a location equivalent to that of the vocal muscle in the CauF. The development of their large diameters was interpreted as part of the maturation process, thereby supporting the hypothesis of their functional importance as a component of the “body.” In the CauF, the amounts of collagen structures increased throughout the entire lamina propria, resulting in a loss of demarcated stratigraphical subdivisions in the “old” minipigs. This situation resembled that described in the vocal fold of geriatric humans.

Juvenile Ovine Ex Vivo Larynges: Phonatory, Histologic, and Micro CT Based Anatomic Analyses

“…In summary, these results show that old sheep exhibit (1) stiffer collagen network due to thicker and shortened fibers; (2) lower tissue viscoelasticity due to reduced HA-level, resulting in reduced water storage and hence in reduced ability to shock absorption due to the constant trauma caused by the vibratory actions of phonation; (3) increased inertance yielding a reduced dynamic range; (4) more random distributed fat inclusion that may to a certain point also explain the reduced systematic behavior in the phonatory experiments; (5) reduced elastin concentration, yielding less changes in vocal fold elongation and hence less overall accurately dynamical measurable differences. These results are consistent with the previously published results in human, rat, and mini-pig aging larynx [ 24 – 26 ].…”

The resveratrol-enriched rice DJ526 boosts motor coordination and physical strength

“…5 ). Because previous studies showed that the quantity of collagen in skin is an important indicator of aging 27 28 29 30 31 , the medial thickness of the collagen in skin was quantitated using the Image-J system. The medial thickness of collagen in skin after the 3-month experimental period was 327.8 ± 13.4 μm in the DJ526 group, 203.3 ± 7.5 μm in the DJ group, 204.4 ± 10.2 μm in the RS group, and 177.8 ± 7.0 μm in the control group ( Fig.…”

“…6 ). It has been well known that a thick collagen layer in the body indicates youth in mammals, and the collagen layer becomes thinner as it ages 27 28 29 30 31 . Therefore, the healthy thickness of collagen as well as up-regulation of anti-aging related pathways in the DJ526 treated group can explain why the DJ526-treated mice were vastly superior in physical strength than the RS or DJ treated group.…”