Sex steroid binding proteins (SSBP) have been reported in the plasma of female and male Rana esculenta. In both sexes SSBP bind [3H]estradiol and [3H]testosterone with medium-high affinity and high specificity. Using ion- exchange chromatography SSBP resolve into two peaks eluting at 0.27 M (peak I) and 0.36 M (peak II) NaCl. Both peaks bind [3H]estradiol and [3H]testosterone equally well. Isoelectrofocusing showed that peak I focused at pH 6.0 and 7.5, whereas peak II focused at pH 6.0. SSBP capacity for [3H]estradiol and [3H]testosterone changes throughout the reproductive cycle, showing low levels during the nonbreeding period and increasing levels during the breeding period. Hypophysectomy and/or gonadectomy result in small changes in SSBP capacity. Short-term steroid hormone treatment of gonadectomized animals does not modify SSBP capacity.
|Titolo:||Sex steroid binding proteins (SSBP) in the plasma of the green frog, Rana esculenta. Changes during the reproductive cycle and dependence on pituitary gland and gonads". Gen. and Comp. Endocrinol.,|
|Data di pubblicazione:||1994|
|Appare nelle tipologie:||1.1 Articolo in rivista|