Endocrinology, Vol 109, 1394-1398, Copyright © 1981 by Endocrine Society

ARTICLES

Sex-related difference in the release of dopamine into hypophysial portal blood

GA Gudelsky and JC Porter

The concentration of dopamine (DA) in pituitary stalk plasma of cycling female rats during diestrus was approximately 7 times that in stalk plasma of intact male rats, and the rate of DA synthesis in the median eminence of diestrous female rats was 5 times that in the median eminence of intact male rats. DA concentrations in pituitary stalk plasma of castrated adult male rats, orchiectomized as adults or as 1- day-old neonates, did not differ significantly from those of intact adult male rats. However, treatment of male rats with 17 beta-estradiol benzoate for 3 days resulted in a significant (P less than 0.005) increase in the concentration of DA in pituitary stalk plasma. DA concentrations in stalk plasma of adult female rats, ovariectomized as adults or treated with testosterone propionate (50 micrograms) on day 1 of life, did not differ appreciably from those of diestrous female rats. However, DA concentrations in stalk plasma of adult female rats that had been ovariectomized on day 14 of life were significantly (P less than 0.01) lower than those of diestrous female rats. In view of these results, it is concluded 1) that there is a sex-related difference in the release of DA from tuberoinfundibular neurons into hypophysial portal blood, and 2) that this difference is not due to a suppressive action of androgen on the secretion of DA in the male rat, but is a consequence of a stimulatory action of estrogen on the release of DA in the female rat.

This article has been cited by other articles:

				W. Yin and A. C Gore Neuroendocrine control of reproductive aging: roles of GnRH neurons. Reproduction, March 1, 2006; 131(3): 403 - 414. [Abstract] [Full Text] [PDF]

				S. T. Hentges and M. J. Low Ovarian Dependence for Pituitary Tumorigenesis in D2 Dopamine Receptor-Deficient Mice Endocrinology, December 1, 2002; 143(12): 4536 - 4543. [Abstract] [Full Text] [PDF]

				M. E. Freeman, B. Kanyicska, A. Lerant, and G. Nagy Prolactin: Structure, Function, and Regulation of Secretion Physiol Rev, October 1, 2000; 80(4): 1523 - 1631. [Abstract] [Full Text] [PDF]

				A. Muranyi, P. Gergely, M. I. K. Fekete, and G. M. Nagy Protein Phosphatase 2A Plays a Role in the Suckling-Induced Changes in the Responsiveness of Pituitary Mammotropes Endocrinology, November 1, 1998; 139(11): 4590 - 4597. [Abstract] [Full Text] [PDF]

				S. Cheung, Y. M. Will, K. Hentschel, K. E. Moore, and K. J. Lookingland Role of Gonadal Steroids in Determining Sexual Differences in Expression of Fos-Related Antigens in Tyrosine Hydroxylase-Immunoreactive Neurons in Subdivisions of the Hypothalamic Arcuate Nucleus Endocrinology, September 1, 1997; 138(9): 3804 - 3810. [Abstract] [Full Text] [PDF]