Effects of Protein Deprivation on α1(I) and α1(III) Collagen and Its Degrading System in Rat Skin

Dietary Protein as a Potent Regulator of the Hyaluronan Synthase Gene in Rat Skin

“…1. As previously reported, 7) the body weight of the G-fed rats remained unchanged, and that of the PF-fed rats decreased, despite the normal weight gain of the control group ( Fig. 1(a)).…”

“…reduction in skin weight by a relatively short period of protein malnutrition is in accordance with the results of Tanaka and our previous study. 7,20) The decreased level of hyaluronan is consistent with the report by Kaggwa,10) in which rats were fed on a very low protein diet. The reduction in hyaluronan content probably contributes much to the reduced skin weight, since hyaluronan, together with the abundant water absorbed to it, comprise the major part of the skin.…”

“…21) Additionally, as we have previously shown, protein malnutrition also causes drastic decreases in type I and type III collagen, along with a decrease in the gene expression of their constituents. 7) Thus, protein malnutrition reduces both collagens and hyaluronan and thereby induces loss of the weight and function of the skin. Interestingly, the gene expression of type III collagen, which is thought to be important for wound-healing and skin remodeling, 22) was more severely aŠected by protein nutrition than type I collagen.…”

“…Of the mechanism for deterioration of the skin under protein malnutrition, changes in such the proteinous components as collagens have been well documented in many situations. [7][8][9] On the other hand, the eŠect of protein nutrition on the hyaluronan metabolism has been far less characterized. In 1986, Kaggwa reported that a very-low-protein diet signiˆcantly decreased the hyaluronan content in rat skin.…”

Effect of Protein Malnutrition on the Skin Epidermis of Hairless Mice

“…PM affects the status of dermal collagen in humans and experimental animals. Oishi et al [25] reported that the synthesis and degradation of types I and III collagen were affected by protein deficiency. However, to our knowledge, there have been no reports about the effect of PM on the skin epidermis.…”