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Effect of tyrosine on serum concentrations of lh, fsh and testosterone in adult men

Ni Jiang, Gao Erwei, Cheng Chiping

The Reproductive Endocrinology Laboratory, Harbin Medical University. Heilongjiang, China

Abstract

The effect of tyrosine on serum concentrations of LH, FSH and testosterone (T) in 10 adult young men was studied in order to find out whether tyrosine affects the secretion of gonadotropins by the pituitary. Five subjects took L-tyrosine orally 100mg t.i.d. for 6 days, and five served as control. Blood samples were taken between 8:00-9:00 each day for the determination of LH, FSH and T by RIA. On the morning of the fifth day, all subjects were injected intramuscularly with 150IAg LRH-A. Blood samples were then obtained 15, 30, 45, 60, 90, 120, 240 min and 24 h after the injection. The results showed that tyrosine did not alter both the basic levels and the LRH-A-stimulated rise of serum LH and FSH, but was capable of increasing the basic secretion of T slightly. However, tyrosine significantly inhibited the increase in T concentration which was expected to occur after the LRH-A injection. It is, therefore, believed that tyrosine may exert some inhibitory effect.

Key words: L-tyrosiae;LH;FSH;Gonadotropias;Testosterone

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Citing This Article：

Ni Jiang, Gao Erwei, Cheng Chiping. Effect of tyrosine on serum concentrations of lh, fsh and testosterone in adult men. Acta Physiol Sin 1985; 37 (3): (in Chinese with English abstract).