Browsing by Subject "Hair cycle"

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    Age-related changes in the dorsal skin histology in Mini and Wistar rats
    (Murcia : F. Hernández, 2002) Ikawa, A.; Ishii, Y.; Suzuki, K.; Yasoshima, A.; Suzuki, N.; Nakayama, Hiroyuki; Takahashi, S.; Doi, K.
    Mini rats (Jcl: WistarTGN(ARGHGEN)1Nts (MRs) are Wistar rat (WR)-derived transgenic rats in which the expression of growth hormone (GH) gene is suppressed by the presence of antisense transgene. The plasma GH level of MRs is reduced to 40 to 60% of that of WRs. In this study, to evaluate the influence of GH deficiency on the skin nature, age-related changes in the dorsal skin histology were compared between male MRs and WRs. Although there were no essential differences in the skin structures between the two strains, MRs had thinner skin with less collagens, more ab u n d a n t subcutaneous adipose tissues and small-sized sebaceous glands compared with WRs. On the other hand, the hair cycle evaluated by the morphology and the depth of hair follicles was greatly different between them. Namely, two cycles of 4 weeks each were observed in both strains during the first 8 weeks after birth, but the cycle entered a long-lasting quiescence (telogen phase) in MRs while the 3rd cycle started in WRs afterwards. The lower level of serum insulin-like growth factor (IGF)-1 in MRs may be related to such a difference in hair cycle pattern, although the levels of IGF-1 and IGF-1 receptor mRNAs in the dorsal skin tissues were similar between MRs and WRs. MRs are considered to be a useful animal model for dermatopathy in patients suffering from GH deficiency and for grasping a clue to elucidate the exact e ffects of GH on the skin nature, especially on hair follicle development.
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    Expression of galectin-l and -3 and of accessible binding sites during murine hair cycle
    (Murcia : F. Hernández, 2000) Wollina, U.; Lange, D.; Paus, R.; Burchert, M.; Gabius, H.J.
    Although protein-carbohydrate interactions are supposed to play key roles in cell adhesion, signalling and growth control. Their exact role in skin physiology has only recently been investigated. The endogenous lectins galectin-l and galectin-3 have been identified in skin including hair follicles. Here, we analyzed the expression and distribution of these galectins and their binding sites in C57BL/6 mice during hair cycle. The expression of galectin-l and galectin-3 binding sites was found to be predominantly hair cycledependent showing some overlapping to the expression of galectin-l and -3. The outer root sheath (ORS) expressed galectin-l binding sites during anagen IV to V1 and in early catagen, whereas galectin-l was expressed from early anagen to late catagen. The ORS expressed galectin-3 binding sites during catagen transition corresponding to a galectin-3 expression during anagen V and catagen. The innermost layer of the ORS expressed galectin-3 binding sites during anagen V1 until catagen VIII, but galectin-3 during anagen I11 to IV and catagen. The inner root sheath (IRS) expressed galectin-3 binding sites only in anagen IV but missed expression of any of the two galectins. The matrix cells expressed galectin-3 binding sites in catagen 11-111 as well as galectin-3 during anagen V to catagen IV. The present study provides the first evidence for a cyclerelated expression of both galectin-l and -3 and their binding sites during murine hair cycle.