CONTROL OF LHRH SECRETION IN THE MALE

申请人已经表明，睾酮（T）作用于大脑， 降低促性腺激素释放激素（GnRH）脉冲频率。 的 拟议研究的总体目标是检验一般假设 T抑制男性的GnRH脉冲频率，部分原因是 在医学视前区（mPOA），以增加γ分泌 氨基丁酸（GABA），减少谷氨酸的分泌， 天冬氨酸，兴奋性氨基酸（EAA）。 具体目标是： 1.为了验证T对GNRN具有抑制作用的假设， 脉冲频率通过作用于mPOA。 这将通过以下方式解决： 双侧微植入睾丸激素到mPOA，弓状- 腹内侧区（ARC-VMR），同时两个区域，然后 监测切除或切除后LH脉冲模式的后续变化 （ORCH）公羊。 2. 为了验证GABA抑制GnRH脉冲频率的假设， 公羊。 这将通过灌注GABA激动剂和拮抗剂来完成 然后监测ORCH中LH脉冲模式的变化 和ORCH，T处理的公羊。 3. 检验EAA增加GnRH脉冲频率的假设。 这 将通过将EAA激动剂和拮抗剂灌注到 ORCH和T处理的ORCH公羊，然后监测LH脉冲的变化 频率. 4. 为了验证T升高GABA和减少EAA分泌的假设， 在mPOA。 这将通过监测GABA和EAA从 采用推拉式套管同时监测循环的POA 用T或稀释剂处理的ORCH公羊中的LH。 5. 为了检验零假设， 振荡的GABA，和EAA分泌的mPOA和GnRH释放。 GABA、EAA、GnRH、 在ORCH和ORCH + T处理的公羊中进行LH分泌。 这些研究对于了解GnRH的控制和 脉冲发生系统与T对GnRH和LH的调节作用 分泌物

The applicant has shown that testosterone (T) acts on the brain to decrease gonadotropin releasing-hormone (GnRH) pulse frequency. The overall aim of the proposed studies is to test the general hypothesis that T suppresses GnRH pulse frequency in the male, in part, by acting at the medical preoptic area (mPOA) to increase secretion of gamma aminobutyric acid (GABA), and decrease secretion of glutamate and aspartate, excitatory amino acids (EAA). The specific aims are: 1. To test the hypothesis that T exerts its inhibitory effect on GNRN pulse frequency by acting at the mPOA. This will be addressed by placing bilateral microimplants of the testosterone into the mPOA, the arcuate- ventromedial region (ARC-VMR), and both regions simultaneously, and then monitoring subsequent changes of LH pulse patterns in or chidectomized (ORCH) rams. 2. To test the hypothesis that GABA suppresses GnRH pulse frequency in the ram. This will be done by perfusing GABA agonists and antagonists into the mPOA and then monitoring changes of LH pulse patterns in ORCH and ORCH, T-treated rams. 3. To test the hypothesis that EAAs increase GnRH pulse frequency. This will be done by perfusing EAA agonists and antagonists into the mPOA of oRCH and T-treated ORCH rams and then monitoring changes in LH pulse frequency. 4. To test the hypothesis that T elevates GABA and reduces EAA secretion in the mPOA. This will be done by monitoring GABA and EAA release from the POA using push-pull cannule and simultaneously monitoring circulating LH in ORCH rams treated with T or diluent. 5. To test the null hypothesis that there is little coincidence between oscillations of GABA, and EAA secretion in the mPOA and of GnRH release. A longitudinal study of simultaneous temporal changes of GABA, EAA, GnRH, and LH secretion will be done in ORCH and ORCH + T-treated rams. These studies are important for understanding both control of the GnRH pulse-generating system and the action of T in regulating GnRH and LH secretion.