The development of ACTH-like substance during tadpole metamorphosis.
The interrenals of tadpoles of Rana catesbeiana at various developmental TK stages were frozen, sectioned, and prepared histochemically for assessment of delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) activity. The interrenals of hypophysectomized (HX) tadpoles from the same batch of eggs as control tadpoles were prepared similarly for delta 5-3 beta-HSD activity following a series of intraperitoneal injections of different concentrations of mammalian ACTH. The histochemically stained sections of control and HX tadpoles were scanned with a computerized microscope spectrophotometer for diformazan absorbance. Two regression equations were obtained: Y = 0.1460 + 0.0015X and Y' = 0.1494 + 0.0893X', where Y or Y' = delta 5-3 beta-HSD activity absorbance (for the control and HX tadpoles, respectively), X = developmental stages of control, and X' = exogenous ACTH dosage administered to the HX tadpoles. Taking absorbance of delta 5-3 beta-HSD activity as the common factor, a curve of concentrations of ACTH-like substance against TK stages was made. The developing concentration of ACTH-like substance was very low at first and then rose during metamorphic climax. The trend of the development of ACTH-like substance was discussed from the view point of thyroid and delta 5-3 beta-HSD activities.
Yu
N W
NW
Hsu
C Y
CY
Ku
H H
HH
Wang
H C
HC
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D007016:Hypophysectomy; D007401:Interrenal Gland / Q000187:drug effects / Q000378:metabolism; D007814:Larva / Q000378:metabolism; D008675:Metamorphosis, Biological; D011892:Rana catesbeiana / Q000254:growth & development*; D012044:Regression Analysis
D000324:Adrenocorticotropic Hormone; D015096:3-Hydroxysteroid Dehydrogenases