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SOME QUANTITATIVE STUDIES ON TISSUES OF LAMBS DWARFED BY HIGH TEMPERATURES DURING GESTATION
Author(s) -
Ryle Margaret,
Morris LR
Publication year - 1961
Publication title -
australian journal of experimental biology and medical science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0004-945X
DOI - 10.1038/icb.1961.8
Subject(s) - endocrinology , dwarfing , zona fasciculata , medicine , anterior pituitary , biology , thyroid , medulla , gestation , epithelium , pregnancy , adrenal cortex , hormone , botany , genetics , rootstock
SUMMARY Quantitative studies were made on the anterior pituitary, thyroid, adrenal and bladder epithelium of normal new‐born lambs and lambs from ewes exposed to high environmental temperatures during the last two‐thirds of pregnancy. The mean relative weights of the anterior pituitaries and of the adrenals of the dwarfed hot‐room lambs were significantly greater than those of the controls. Where the experimental treatment caused dwarfing, the pituitary cell size was less than in the controls and intensely chromophilic nuclei were more frequent. However, the total number of anterior pituitary cells did not appear to be affected. The area and height of the nuclei (and cells) and the number of cell layers in the bladder epithelium were also reduced in the dwarf lambs. Regardless of body weight, the hot‐room lambs tended to have smaller adrenal cortices, and the mean area of the nuclei in the zona fasciculata was less than that of the controls. The quantity of adrenal medulla, however, appeared to be unaffected by the treatment, even where dwarfing occurred. No significant differences were detected between the thyroids of the hot‐room animals and those of the controls. The results are discussed in relation to possible mechanisms through which high environmental temperatures might affect the tissues studied.