In the present study, a perfusion system of dispersed cells was used to investigate theeffects of LHRH pulse amplitude and frequency, and LHRH continuous stimulation on LHsecretion by anterior pituitary cells of adult...In the present study, a perfusion system of dispersed cells was used to investigate theeffects of LHRH pulse amplitude and frequency, and LHRH continuous stimulation on LHsecretion by anterior pituitary cells of adult male rats. The results have shown that, in therange of LHRH concentrations from 1×10^(-10) to 1 ×10^(-6) mol/L, the dose-response curve of LHsecretion was linear. LHRH pulse frequency generated a biphasic LH response: increasingLHRH pulse frequency increased the basal LH secretion and decreased LH/pulse. When1 ×10^(-9), mol/L or greater LHRH was given at frequencies of 3 pulses/h or higher, it wasobserved that a maximal LH peak was induced and then the LH release declined progres-sively to its LH basal level, i.e. LHRH self-priming effect and LH desensitization occurred.Enhancement of amplitude of LHRH pulses could reduce pulse frequency required for prim-ing. Increases in frequency of LHRH pulses with high amplitude would provoke the prim-ing effect more quickly. In addition, continuous perfusion of LHRH with different con-centrations could also elicit the LHRH self-priming effect and LH desensitization. LHRHwith low concentration (1×10^(-10) mol/L) would take much longer to evoke a self-primingeffect. These results indicate that the LH secretion pattern is dependent on LHRH pulsatileamplitude and frequency, and will help to clarify the kinetics mechanisms by which LHpulses fluctuate in vivo.展开更多
基金This work was supported by grants from WHO special programme of Research, Development and Research Training in Human Reproduction, and Family Planning Committee of Sichuan Province.
文摘In the present study, a perfusion system of dispersed cells was used to investigate theeffects of LHRH pulse amplitude and frequency, and LHRH continuous stimulation on LHsecretion by anterior pituitary cells of adult male rats. The results have shown that, in therange of LHRH concentrations from 1×10^(-10) to 1 ×10^(-6) mol/L, the dose-response curve of LHsecretion was linear. LHRH pulse frequency generated a biphasic LH response: increasingLHRH pulse frequency increased the basal LH secretion and decreased LH/pulse. When1 ×10^(-9), mol/L or greater LHRH was given at frequencies of 3 pulses/h or higher, it wasobserved that a maximal LH peak was induced and then the LH release declined progres-sively to its LH basal level, i.e. LHRH self-priming effect and LH desensitization occurred.Enhancement of amplitude of LHRH pulses could reduce pulse frequency required for prim-ing. Increases in frequency of LHRH pulses with high amplitude would provoke the prim-ing effect more quickly. In addition, continuous perfusion of LHRH with different con-centrations could also elicit the LHRH self-priming effect and LH desensitization. LHRHwith low concentration (1×10^(-10) mol/L) would take much longer to evoke a self-primingeffect. These results indicate that the LH secretion pattern is dependent on LHRH pulsatileamplitude and frequency, and will help to clarify the kinetics mechanisms by which LHpulses fluctuate in vivo.
