Humoral regulation of hemoglobin transition from larval to adult types in a salamander, Hynobius retardatus.

摘要: Abstract In amphibians hemoglobin (Hb) transition from larval to adult types occurs during metamorphosis. Hemoglobin in the salamander Hynobius retardatus also metamorphosis, but depends on activity of pituitary gland, rather than that thyroid gland. These findings were supported by fact transplanted gland hypophysectomized (Hx) larvae exerted accelerating effects Hb transition. Contrary this, a homogenate Xenopus laevis had no effect when injected into Hx H. retardatus. Whereas exogeneously applied triiodothyronine (T 3 ) or combination T and hydrocortisone an larvae, single treatment with effect. When inhibitor synthesis adrenocortico-steroid hormones, metyrapone, was goitrogens intact suppressed compared normal controls, suggesting thyroid–corticoid system is involved results suggest controlled two independent factors, both system. control mechanisms are different general regulation metamorphosis many amphibians. A tentative model hormonal controls presented.