TY - JOUR
T1 - Excitatory amino acid receptors and puberty
AU - Zamorano, Pedro L.
AU - Mahesh, Virendra B.
AU - De Sevilla, Liesl
AU - Brann, Darrell W.
N1 - Funding Information:
This work was supported by a Research Grant (to D.W. B.) from the National Institute of Child Health and Human Development (R01HD28964), National Institutes of Health, United States Public Health Service.
PY - 1998/5
Y1 - 1998/5
N2 - Glummate is an important excitatory signal in the hypothalamus for the steroid-mediated preovulatory gonadotropin surge. Steroids may exert this action by regulating glummate receptor levels or glutamate release, or both. Work in our laboratory found no changes in NMDA and kainate receptor binding in the hypothalamus of castrated or castrated plus steroid-replaced male and female rats. Likewise, we found that NMDA and kainate binding did not change over the onset of puberty in the female rat. A competitive quantitative RT- PCR assay using exogenous internal standards was used to measure NMDARI, GluR1, and β-actin mRNAs levels. NMDARI and GluR1 expression was examined in the preoptic hypothalamic area and in the medial basal hypothalamus at Postnatal Days 10, 15, 20, 25, 30, 32, 34, 36, 40, and 63. A transient increase in GluR1 mRNA levels in the preoptic hypothalamic area was observed on Day 20, with all other time points showing comparable levels. NMDARI levels in the POA and medial basal hypothalamus did not change significantly at any of the time points; in contrast, however, AMPA receptor binding levels were increased in the hypothalamus at the time of puberty in the female rat. Thus, in addition to the previously reported elevation of glutamate release rates in the hypothalamus at the time of puberty, AMPA receptors may also be elevated and play a role in mediating glutamate regulatory effects on the timing of puberty in the female rat.
AB - Glummate is an important excitatory signal in the hypothalamus for the steroid-mediated preovulatory gonadotropin surge. Steroids may exert this action by regulating glummate receptor levels or glutamate release, or both. Work in our laboratory found no changes in NMDA and kainate receptor binding in the hypothalamus of castrated or castrated plus steroid-replaced male and female rats. Likewise, we found that NMDA and kainate binding did not change over the onset of puberty in the female rat. A competitive quantitative RT- PCR assay using exogenous internal standards was used to measure NMDARI, GluR1, and β-actin mRNAs levels. NMDARI and GluR1 expression was examined in the preoptic hypothalamic area and in the medial basal hypothalamus at Postnatal Days 10, 15, 20, 25, 30, 32, 34, 36, 40, and 63. A transient increase in GluR1 mRNA levels in the preoptic hypothalamic area was observed on Day 20, with all other time points showing comparable levels. NMDARI levels in the POA and medial basal hypothalamus did not change significantly at any of the time points; in contrast, however, AMPA receptor binding levels were increased in the hypothalamus at the time of puberty in the female rat. Thus, in addition to the previously reported elevation of glutamate release rates in the hypothalamus at the time of puberty, AMPA receptors may also be elevated and play a role in mediating glutamate regulatory effects on the timing of puberty in the female rat.
KW - Glutamate receptor
KW - Hypothalamus
KW - Puberty
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U2 - 10.1016/S0039-128X(98)00033-6
DO - 10.1016/S0039-128X(98)00033-6
M3 - Article
C2 - 9618783
AN - SCOPUS:0032076992
SN - 0039-128X
VL - 63
SP - 268
EP - 270
JO - Steroids
JF - Steroids
IS - 5-6
ER -