Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 2

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
 In quest of alternate, extradermal path of melanin transfer from skin to the visceral organs, we suggested that some portions of such melanin may be deposited in the spleen, which in young black C57BL/6 mice is often melanized. Here, we confirm these observation using young C57BL/6 female mice (up to 17 weeks) and show that this phenomenon cannot be observed in old animals where the hair cycle is not synchronized any more. The experiments were carried out both on spontaneous and depilation-induced hair cycle. We have checked it as a side-observation over many other experiments carried out on young and old C57BL/6 female mice (up to 2.5 years of life). The presence or absence of melanin in the spleens was checked macroscopically, and histologically by Fontana-Masson (FM) staining, and synchronization of the hair cycle - by standard histomorphometric analysis of the back skin hair follicles. In about 40% of old spleens black FM-stainable "debris" could be found under closer histological examination. This study shows that, at least in part, the phenomenon of splenic melanosis in C57BL/6 mice can be correlated with the synchronized skin melanization parallel to the hair cycle progress, and that splenic melanin undergoes gradual degradation during the mouse life.
 Cancer chemotherapy is associated with serious side effects, including temporary hair loss and impairment of pigmentation. We suspect that ectopic melanin deposition occurring due to chemotherapy may add to these effects worsening the already unpleasant symptoms. We associated the ectopic occurrence of follicular melanin after chemotherapy with splenic melanosis - an interesting example of extradermal melanin localization - and we expected an increase in splenic melanin deposition after chemotherapy. Using the C57BL/6 murine model of synchronized hair cycle induced by depilation, we visualized splenic melanin by means of several histological and histochemical protocols of staining: hematoxylin and eosin, May-Grünwald-Giemsa and Fontana-Masson. Unexpectedly, the splenic deposition of melanin decreased due to application of cyclophosphamide (i.p. 120 mg/ kg body weight on day 9 post depilation). The drop was abrupt and lasted for at least 5 days (day 13-18 post depilation), as compared with normal hair cycle. Moreover, in mice with normal, depilation-induced hair cycle we observed a similar drop shortly before entering catagen (day 15 post depilation), followed by a slow and partial increase in splenic melanization up to day 27 post depilation in both groups. We conclude that cyclophosphamide negatively affects splenic melanization and/or extradermal transfer of ectopic melanin from the dystrophic hair follicles, but the most powerful down-regulator of splenic melanosis is normal and dystrophic catagen - the phase of hair follicle involution and re-modelling.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.