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Urinary excretion pattern of catecholestrogens in preovulatory LH surge during the 4-day estrous cycle of rats.

Research paper by S K SK Panda, S C SC Chattoraj

Indexed on: 16 Jun '01Published on: 16 Jun '01Published in: Journal of Endocrinological Investigation



Abstract

The formation of catecholestrogens represents a major pathway of estrogen metabolism and catecholestrogens are regarded as the main estrogen metabolite in non-pregnant state of various mammalian systems. In the present investigation, level of 2-hydroxyestrone, the major catecholestrogen excreted in rat urine, was measured by radioimmunoassay following acid hydrolysis and column chromatography of the 24-h urine samples of female Sprague Dawley non-pregnant rats during their 4-day estrous cycle. Urinary levels of estrone, estradiol and estriol were measured. Unlike the plasma level, urinary 2-hydroxyestrone showed a marked increase during the pre-ovulatory LH surge suggesting a plausible role of catecholestrogen in the mid-cycle elevation of the gonadotropin level in normal cycling rats.