Abstract
In normal, non-expanding toad epidermis more cells are produced than needed to replace cells lost by moulting. By implication, cell deletion additional to moulting must take place. This paper deals with the mechanisms by which the "surplus" of cells is deleted, taking advantage of the fact that the ratio between cell birth rate (Kb) and the rate of desquamation (Kd), which in normal toads is 2 to 3, can be manipulated. In toads deprived of the pars distalis of the pituitary gland it is decreased to 0.2 to 0.3, and in toads with hydrocortisone pellets implanted into the subcutaneous lymph space it is increased to 7 to 10. Thus, structures candidates for the morphological manifestation of the deletion process should occur rarely in toads in which the pars distalis has been removed and frequently in toads with hydrocortisone pellets implanted. Categorization and enumeration of such structures by light microscopy in the epidermis from operated, normal, and hormone-treated toads were performed. The incidence of structures referred to as "dark cells" and "omega-figures" were found to correlate relatively well with the Kb/Kd-ratio. A subsequent ultrastructural analysis - on a cell-by-cell basis - of "dark cells" showed these to reflec...Continue Reading
Citations
Mar 1, 1994·Developmental Dynamics : an Official Publication of the American Association of Anatomists·R R PolakowskaA R Haake
Aug 1, 1994·The Histochemical Journal·G ZacconeL Ainis
Apr 1, 1995·Cell and Tissue Research·P E BudtzN J Willumsen
Oct 1, 1996·Archives of Dermatological Research·U HenseleitG Kolde
Dec 21, 2007·Clinical Reviews in Allergy & Immunology·Julie H LinVictoria P Werth
Jan 1, 1990·Acta histochemica·P E Budtz, G Zaccone
Sep 27, 2000·Journal of Anatomy·H Bartel, A Lametschwandtner
Apr 14, 1999·The Laryngoscope·H J Park, K Park
Aug 7, 1998·Journal of Cutaneous Pathology·T TanakaK Hashimoto
Feb 1, 1993·Experimental Dermatology·R PausB M Czarnetzki
Oct 15, 2013·The Journal of Investigative Dermatology·Janina BärThomas M Magin
Jun 1, 1997·Journal of the American Academy of Dermatology·C A Raskin
Jan 1, 1997·Lupus·S D Bennion, D A Norris
May 19, 2004·FEBS Letters·B PelachoM J López-Zabalza
Jun 25, 2004·Journal of Morphology·Jane C KaltenbachAlina Fakin
Oct 15, 2011·Experimental Dermatology·Hee Jung KimDae Ho Cho
Mar 15, 1996·The Journal of Biological Chemistry·M D Hines, B L Allen-Hoffmann
May 15, 1999·Nucleic Acids Research·P P LaktionovB Lebleu
Feb 21, 1998·The British Journal of Dermatology·S SermadirasM H Ratinaud
May 14, 2021·The Journal of Investigative Dermatology·Anisa B RahimLeah A Vardy