Morello H, Caligaris L, Haymal B, Taleisnik S
Instituto de Investigación Médica Mercedes y Martin Ferreyra, Córdoba, Argentina.
Acta Endocrinol (Copenh). 1990 Jun;122(6):696-702. doi: 10.1530/acta.0.1220696.
The effect of stimulation or lesions of either the dorsal or the median raphe nucleus on the proestrous surge of LH and on ovulation was studied in rats kept under constant illumination. Electrochemical stimulation (anodic DC of 100 microA during 30 sec) was applied at noon on the day of proestrus through chronically implanted electrodes. Lesions of the raphe nuclei were made by passing a cathodic current of 1 mA for 20 sec through nichrome electrodes stereotaxically implanted. Blood samples from freely behaving rats were obtained hourly through cannulae inserted into the jugular vein. Rats under constant light from diestrous day 1 or diestrous day 2 showed a delay in the onset of the LH surge of the next proestrus. Stimulation applied into the median raphe nucleus inhibited proestrous LH release and blocked ovulation, whereas stimulation of the dorsal raphe nucleus resulted in enhanced LH release in rats under constant light from diestrous day 2 but not from diestrous day 1. In turn, in rats bearing lesions in the dorsal raphe nucleus LH surges were decreased and ovulation was blocked, but rats with lesions in the median raphe nucleus exhibited enhanced LH release. It is concluded that the dorsal and the median raphe nuclei exert opposite effects on the proestrous surge of LH and on ovulation.
在持续光照条件下饲养的大鼠中，研究了刺激或损伤背侧或中缝核对于促卵泡素（LH）发情前期激增及排卵的影响。在发情前期当天中午，通过长期植入的电极施加电化学刺激（30秒内100微安阳极直流电）。通过立体定位植入的镍铬合金电极施加1毫安阴极电流20秒，造成中缝核损伤。通过插入颈静脉的套管，每小时从自由活动的大鼠采集血样。从动情间期第1天或动情间期第2天开始持续光照的大鼠，下一个发情前期LH激增的起始出现延迟。刺激中缝核抑制发情前期LH释放并阻断排卵，而刺激背侧中缝核导致从动情间期第2天开始持续光照的大鼠LH释放增强，但从动情间期第1天开始持续光照的大鼠则不然。反过来，背侧中缝核有损伤的大鼠LH激增减少且排卵受阻，但中缝核有损伤的大鼠LH释放增强。得出的结论是，背侧和中缝核对发情前期LH激增及排卵具有相反作用。
