ラットの視床下部神経分泌系に対するLSD系薬物及びSerotoninの脳室内注射の効果

抄録

The effect of lysergic acid derivatives and serotonin on the hypothalamic neurosecretory system were studied in rats and evidence was presented that between these two kinds of drugs an antagonism existed. Animals were divided into untreated control and eight experimental groups : intraventricular injection group with saline, LSD-25 (20μg), LAE-32 (20μg), BOL-148 (20μg), LSD (20μg) plus serotonin (40μg) simultaneously, and BOL (20μg) plus serotonin (40μg) simultaneously, and a supplemental group administered with LSD (100mg) by the intraperitoneal route and serotonin (40μg) by the intraventricular route 30 minutes afterwards.
Each experimental group included 12 rats, and the animals were examined at 1, 2, 3, 6, 12, and 24 hours after the drug administration, respectively.
The results obtained were as follows and were tabulated in a composite chart (Table. 2) :
1) LAE-32 intraventricular injection group
Animals indicating most remarkable changes were those examined at 6 hours and 12 hours following injection. Increase in neurosecretory material and an appearance of the so-called “red pycnosis” were recognized in the cells of supraoptic and paraventricular nuclei. The neurosecretory material in the posterior lobe of hypophysis was also augmented.
2) LSD-25 intraventricular injection group
Increase in neurosecretory material and red pycnosis was also most striking in the 6-hour animals.
3) BOL-148 intraventricular injection group
In 12-hour animals, increase in neurosecretory material was proved.
4) Serotonin intraventricular injection group.
The effect was most conspicuous one hour after injection. The change was also an increase in neurosecretory material and red pycnosis and it subsided gradually in subsequent hours.
5) Serotonin plus LSD-25 intraventricular injection group
In this group, no neurosecretory material was found both in supraoptic and paraventricular nuclei throughout the whole course of observation, the figures being almost identical with those of the untreated control group. It was revealed that the effects of the two drugs were reversed each other and no apparent change came into play.
6) Serotonin plus BOL-148 intraventricular injection group
As in the foregoing group, here too, the increase in neurosecretory material was not pointed out and the figures were almost identical with those of the untreated control group.
7) LSD-25 intraperitoneal injection plus serotonin intraventricular injection group
In this group, no consistent result was obtained, but in one case of each 2-hour, 3-hour and 6-hour animals the findings were just the same as 5).
The above-mentioned results led to the conclusion that LSD-25, its derivatives and serotonin work upon the hypothalamic neurosecretory system accelerating secretion, while lysergic acid derivatives and serotonin were antagonistic each other when administred simultaneously.