Effect of irradiation of the brain tumor with X-ray and heavy ion on sexual behavior.

脑部重离子照射对性行为的影响尚不清楚。本研究旨在探讨碳颗粒、290 MeV/核子、Mono峰15~ 120 Gy、下丘脑5 mm^3的照射场对大鼠下丘脑的影响。我们计划使用相对高剂量的碳照射来评估对交配行为的短期影响，并在照射后1个月、2个月和3个月分别进行30分钟的性行为观察。实验结果如下：1。在15Gy、30Gy、45Gy和60Gy剂量下，照射1个月后，这些动物的交配行为没有变化；然而，暴露于60gy的大鼠在3个月的随访后发现射精和射精减少。在较高剂量（如90Gy、120Gy）下，安装、射精（仅120Gy）和射精（90Gy、120Gy）的数量减少。根据上述实验结果，可以确定碳束照射下丘脑在照射后的短时间内不会抑制交配行为的活性。为了确定重离子对交配行为的慢性影响，有必要在辐照后进行长期随访的进一步实验。

The effect of heavy-ion irradiation to the brain on sexual behavior is not yet known. The present study was designed to determine whether irradiation (carbon particles,290 MeV/nucleon, Mono peak 15~ 120 Gy,irradiation field 5-mm^3 in hypothalamus) to rat's hypothalamus modifies copulatory behavior of male rats. We planned to estimate the short-term effects of carbon-irradiation on copulatory behavior using a relatively high doses, and observation of sexual behavior was conducted for 30 min after 1,2 or 3 months following irradiation.Results obtained are as follows :1.At dosages of 15Gy,30Gy,45Gy and 60Gy, these were no changes in copulatory behavior after 1 month following irradiation ; however, intromission and ejaculation were found to decrease after 3-month follow-up in rats exposed to 60 Gy.2.At higher doses such as 90Gy,120Gy, the number of mounting, intromission (120Gy alone) and ejaculation (90Gy,120Gy) were decreased.From the experimental results described above, it may be possible to determine that carbon beam irradiation to hypothalamus does not inhibit the activity of copulatory behavior for a short period after irradiation. Further experiments that need long-term follow-up after irradiation must be necessary to determine the chronic effects of heavy ions on the copulatory behavior.