Constancy of adult hypothalamic tyrosine hydroxylase after gonadal steroid treatment during development

Vaccari, Andrea; Biassoni, Roberto

doi:10.1002/jnr.490080105

Cited by 2 publications

(1 citation statement)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, a recent bio chemical study did not reveal any sex differences in hypothalamic TH activity [59], and changes in the kinetic parameters of the enzyme following neonatal steroid treat ment were not detected [58]. Taken together with the lack of an effect of gonadectomy on the distribution of TH-stained cells in either sex, these findings suggest that the perinatal androgen treatments resulted in a permanent decrease in the number of dopaminergic cells in the AVPv of the fe male.…”

Section: Discussionsupporting

confidence: 51%

Influence of Perinatal Androgen on the Sexually Dimorphic Distribution of Tyrosine Hydroxylase-Immunoreactive Cells and Fibers in the Anteroventral Periventricular Nucleus of the Rat

Simerly¹,

Swanson

Handa³

et al. 1985

Neuroendocrinology

177

107

View full text Add to dashboard Cite

Recently we reported that the anteroventral periventricular nucleus (AVPv) of the preoptic region contains a dramatic sexual dimorphism in the distribution of tyrosine hydroxylase- (TH-)immunoreactive cells and fibers in the rat. This sexual dimorphism appears to be due to a greater density of dopaminergic fibers, and a larger number of dopaminergic cell bodies, in the AVPv of the female. In the present study we used an indirect immunohistochemical method to evaluate the distribution of TH-immunoreactive cell bodies and fibers, and of dopamine-β-hydroxylase-(DBH-)stained fibers, in the AVPv of female rats that were treated with testosterone propionate (TP) perinatally or postnatally, or were left untreated. All of the postnatally TP-treated animals failed to show a phasic pattern of luteinizing hormone (LH) secretion in response to estrogen and progesterone injections. Both the perinatally and postnatally TP-treated females had polyfollicular ovaries that lacked corpora lutea at the time of gonadectomy. Perinatal TP exposure resulted in what appears to be a complete masculinization of both the number of TH-stained cells and the density of TH-stained fibers in the AVPv. The number of TH-stained cells in the postnatally TP-treated females was also completely masculinized, although the density of TH-stained fibers did not appear to be altered significantly. Gonadectomy resulted in a moderate increase in the density of TH-stained fibers in adult males, and did not significantly affect the fiber density in females, or the number of TH-stained cells in either sex. The distribution of DBH-stained fibers in the AVPv did not appear to be altered in any of the treatment groups. These results suggest that the distribution of dopaminergic fibers in the AVPv may be sensitive to testosterone levels in the adult male, and that although the critical period for the development of this fiber distribution may begin in the prenatal period, the number of dopaminergic cells in the AVPv can be completely sex reversed by a single postnatal dose of TP that appears to correlate with a permanent disruption of the normal pattern of gonadotropin secretion.

show abstract

Section: Discussionsupporting

confidence: 51%