Progesterone receptor gene and protein expression in the anterior preoptic area and hypothalamus of defeminized rats

Abstract

Progesterone receptor (PR) plays an important role during sexual differentiation of the rat brain. The objective of the present study was to determine PR protein and gene expression pattern in preoptic-anterior hypothalamic area (POA-AHA) and hypothalamus (HYP), after estradiol or testosterone treatment during the postnatal critical period of sexual differentiation of the rat brain (defeminized animals). Three-day-old female rats were subcutaneously (s.c.) injected with a single dose of 17beta-estradiol (200 microg), or testosterone enanthate (200 microg), or vehicle (corn oil). POA-AHA and HYP were dissected 3 h, 24 h, and 14 days, as well as on the day of vaginal opening (VO) after treatments. Other animals, previously treated as above, were acutely injected with 17beta-estradiol (5 microg) on the day of VO; POA-AHA and HYP were obtained 3 h later. Total RNA was extracted and processed for semiquantitative RT-PCR and tissue slices were prepared for protein detection by immunohistochemistry. We observed that PR mRNA expression was increased in POA-AHA and HYP of the animals treated with estradiol or testosterone 3 hours after treatments, compared with the vehicle-treated control group. We also found a significant increase in PR mRNA and protein expression in POA-AHA and HYP on the day of VO in both estradiol and testosterone defeminized rats. Interestingly, the acute administration of estradiol on the day of VO (VO + E(2)) did not increase PR mRNA or protein expression in POA-AHA and HYP of either estradiol or testosterone defeminized animals, as opposed to the marked induction observed in the intact animals of the control group. The overall results suggest that estradiol and testosterone treatment during the postnatal critical period of sexual differentiation of the brain modifies the regulation of the PR mRNA and protein expression during early onset of maturity.

Mediobasal Hypothalamic SIRT1 Is Essential for Resveratrol’s Effects on Insulin Action in Rats

“…SIRT1 immunoreactivity was detected using a conventional avidin-biotin immunoperoxidase protocol (33). Briefly, sections were pretreated with 1% H 2 O 2 for 30 min to quench endogenous peroxidase activity, followed by three rinses in 0.1 mol/L PBS and then incubation in 1% NaBH 4 to reduce free aldehydes.…”

Deep brain stimulation in midline thalamic region facilitates synaptic transmission and short-term memory in a mouse model of Alzheimer’s disease

“…For immunohistochemical analysis, FosB immunoreactivity was detected using a conventional avidin–biotin immunoperoxidase protocol [8]. Briefly, free-floating sections were first pretreated with hydrogen peroxide for 10 min to quench endogenous peroxidase activity, followed by two rinses in PBS, and then incubated in 1.0% sodium borohydrate to reduce free aldehydes.…”

Sexual dimorphism in the medial vestibular nucleus of adult rats: Stereological study

“…It has been found that steroid treatment during the postnatal critical period of brain sexual differentiation changes the regulation of the progesterone mRNA and protein expression (Cook et al ., 1999). Administration of sex steroids in the critical period of the central nervous system has permanently altered development of this system (Cook et al ., 1999; Arrieta et al ., 2003). Female‐based sexual dimorphism seen in the adult female MVN may be a result of an over‐expression of progesterone in these animals, which was reported previously by Curran‐Rauhut and Petersen (2002).…”