Hormonal modulation of reproduction-specific thiamin carrier protein in the rat

Malathy, PV and Adiga, PR (1985) Hormonal modulation of reproduction-specific thiamin carrier protein in the rat. In: Journal of Biosciences, 7 (2). pp. 77-94.

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Abstract

The hormonal modulation of thiamin carrier protein in the plasma and uterine luminal secretion during the normal reproductive phases of the animal (estrous cycle and pregnancy) as well as during experimental estrogenisation was investigated in the rat using a specific and sensitive homologous radioimmunoassay procedure developed for this purpose. Following a single injection of estrogen to immature male rats, thiamin carrier protein rapidly accumulated in plasma attaining peak concentration at 48 h and declining thereafter. A 1.5-fold amplification of the inductive response was observed on secondary stimulation with the hormone. The magnitude of the response exhibited a clear dependency on the dose of the steroid hormone, whereas the time at which peak levels of thiamin carrier protein production was remained unaltered in the concentration range of the steroid tested. The inductive effect of estrogen was severely curtailed by the antiestrogens,viz., En- and Zu-clomiphene citrates, while progesterone was incapable of either modulating the estrogen-induced response or eliciting an induction by itself. Cycloheximide drastically blocked the response to estrogen. Evidence for the ability of uterus to serve as yet another independent site of thiamin carrier protein synthesis was obtained byin vitro incorporation of radioactive amino acids into immunoprecipitable thiamin carrier protein in the tissue explants of estrogenised female rats. The levels of thiamin carrier protein in uterine luminal fluid measured during estrous cycle, pregnancy and experimental estrogenisation exhibited remarkable similarity to the plasma thiamin carrier protein profiles.

Item Type:	Journal Article
Publication:	Journal of Biosciences
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Keywords:	Thiamin carrier protein;radioimmunoassay;estrogen induction; specificity;kinetics;antiestrogens;Secondary stimulation; kphysiological modulation;uterine synthesis.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	10 Jul 2008
Last Modified:	01 Mar 2012 06:19
URI:	http://eprints.iisc.ac.in/id/eprint/14894

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