caa a22 4500 465826598 CHVBK 20180323112151.0 cr unu---uuuuu 170327e19900801xx s 000 0 eng 10.1007/BF00302592 doi (NATIONALLICENCE)springer-10.1007/BF00302592 Further studies on the regulation of the Harderian glands of golden hamsters by the thyroid gland [Elektronische Daten] [Roger Hoffman, Peter Habeeb, Gerald Buzzell] Summary: Long-term increased or decreased circulating levels of thyroid hormones significantly modify porphyrin concentrations and morphology in the Harderian glands of male and female hamsters. Administration of T3 reduced porphyrin concentrations in females; this treatment or decreasing thyroid hormone levels with KClO4 suppressed the post-castration rise of porphyrins in males. Hypophysectomy led to increased porphyrins in the Harderian glands of males; this rise was suppressed in hypophysectomized males by T3 or T4. In females, hypophysectomy reduced porphyrins which were further reduced by daily administration of T3 or T4. These modifications in the normal females were identical in castrated males. Mitotic activity in the Harderian glands of females was stimulated by KClO4 and by hypophysectomy with or without exogenous T3. In males, castration increased mitotic activity which was suppressed by T3 and exacerbated by KClO4. Increased mitotic activity seemingly follows loss of tissue mass. The data show that thyroid hormones act directly on the Harderian glands rather than indirectly through modification of TSH synthesis/release. Female "type” glands in males are a consequence of loss of gonadal androgens by castration, or by suppression or loss of thyroid hormones by hypophysectomy or by treatment with KClO4. However, male "type” glands in females are the result of androgen treatment, and/or increased levels of thyroid hormones via reduced ambient temperatures or of photic input. We conclude that regulation of the Harderian gland appears to be different in the two sexes. Springer-Verlag, 1990 Harderian glands nationallicence Thyroid hormones nationallicence Pituitary gland nationallicence Porphyrins nationallicence Mitotic index nationallicence T 3 : Triiodothyronine nationallicence T 4 : Thyroxine nationallicence TSH : Thyroid Stimulating Hormone nationallicence KClO 4 : Potassium Perchlorate nationallicence h : hours nationallicence ml : milliliter nationallicence mg : milligram nationallicence g : gram nationallicence ♂ : male nationallicence ♀ : female nationallicence ♂ : castrated male nationallicence AP : hypophysectomized nationallicence CON : Control nationallicence ALA : delta aminole-vulenic acid nationallicence HG : Harderian Gland nationallicence Hoffman Roger Department of Biology, Colgate University, 13346, Hamilton, NY, USA aut Habeeb Peter Department of Biology, Colgate University, 13346, Hamilton, NY, USA aut Buzzell Gerald Department of Anatomy and Cell Biology, University of Alberta, T6G 2H7, Edmonton, Alberta, Canada aut Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 269-275 0174-1578 160:3<269 1990 160 360 https://doi.org/10.1007/BF00302592 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00302592 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hoffman Roger Department of Biology, Colgate University, 13346, Hamilton, NY, USA aut NATIONALLICENCE 700 1- Habeeb Peter Department of Biology, Colgate University, 13346, Hamilton, NY, USA aut NATIONALLICENCE 700 1- Buzzell Gerald Department of Anatomy and Cell Biology, University of Alberta, T6G 2H7, Edmonton, Alberta, Canada aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 269-275 0174-1578 160:3<269 1990 160 360 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer