産褥期におけるβ-endorphinの動態と生理的意義

抄録

β- endorphin (β-Ep) and prolactin (PRL) levels in the sera of 22 normal puerperal lactating women were measured before and 30 min, 60 min and 120 min after suckling.
β-Ep was extracted using the silicic acid method. In 17 cases, β-Ep was measured using the direct RIA method (Anti-β-Ep serum : SRL Inc.). In 5 cases, the specimens were chromatographed and measured using a β-endorphin [¹²⁵I] RIA Kit (NEN).
PRL levels were measured using a prolactin RIA Kit (Daiichi).
In the non-chromatographed group, β-Ep concentrations before and at 30 min, 60 min and 120 min after suckling were 18.8± 6.0, 21.7±7.2, 21.3±8.6 and 13.7±4.5pg/ml (mean±SD), respectively. β-Ep concentrations after suckling were slightly higher than that before suckling.
In the chromatographed group, β-Ep concentrations were 85.4±16.6, 92.1±14.2 and 95.3±25.6pg/ml (mean±SD) before, and at 30 min and 60 min after suckling, respectively.
The difference in the β-Ep concentrations determined by the two methods might be related to low sensitivity of the direct RIA method, though its specificity is very high. However, in the both groups, the β-Ep response patterns before and after suckling were similar.
The PRL concentration was 203.7±141.9 before suckling. The level increasd to 360.1±248.7 at 30 min, 251.4±133.4 at 60 min and 260.7±55.9ng/ml (mean±SD) at 120 min after suckling (p<0.05).
These results suggest that suckling stimulates β-Ep and PRL release possibly from the pituitary gland. However, there was no significant correlation between β-Ep and PRL concentrations. [Adv Obster Gynecol 47(2) : 316-324, 1995 (H7.3)]