Sicuteri F, Del Bene E, Fonda C
Monogr Neural Sci. 1976;3:94-101. doi: 10.1159/000399340.
Sexual deficiency or frank impotence in man could be due to an imbalance of monoamines, particularly 5-HT, at the mating center level. An absolute or relative excess of 5-HT seems to antagonize testosterone at the level of the mating center receptors in the brain. Plasma testosterone levels in so-called psychological impotence are normal. When the 5-HT concentration in sexually deficient men is sufficiently decreased with parachlorophenylalanine (PCPA) treatment and testosterone levels increased following its administration, a vivid sexual stimulation appears in about half of the untractable cases. Similar results are observed by substituting testosterone with monoamine oxydase inhibitor (MAOI) in PCPA-treated volunteers. Furthermore, MAOI-PCPA are administered to emphasize the brain shift between serotonin and catecholamines. Yet the PCPA-MAOI treatment avoids the prostate carcinogenic risk of testosterone administration in aging males, and seems to have euphorizing effects stronger than those expected only from MAOI therapy. Because of the several side effects of PCPA-MAOI testosterone, the present experiments should be interpreted very cautiously.
男性的性功能减退或明显阳痿可能是由于在交配中枢水平单胺类物质失衡，尤其是5-羟色胺（5-HT）失衡所致。5-HT的绝对或相对过量似乎在大脑交配中枢受体水平拮抗睾酮。在所谓的心理性阳痿患者中，血浆睾酮水平正常。当用对氯苯丙氨酸（PCPA）治疗使性功能减退男性的5-HT浓度充分降低，并在给药后睾酮水平升高时，约半数难治性病例会出现明显的性刺激。在接受PCPA治疗的志愿者中用单胺氧化酶抑制剂（MAOI）替代睾酮也观察到类似结果。此外，给予MAOI-PCPA以强调血清素和儿茶酚胺之间的脑内转移。然而，PCPA-MAOI治疗避免了老年男性睾酮给药的前列腺致癌风险，且似乎具有比仅MAOI治疗预期更强的欣快感作用。由于PCPA-MAOI睾酮存在多种副作用，对目前的实验应非常谨慎地进行解读。
