The effect of stress on prolactin release is still controversial .A number
of complex mechanisms may be involved includirug a possible role of calcium
ions and opiate peptides . In this work we tried to study the effect of
acute stress on prolactin release and the possible role of calcium channels
blacker and opiate antagonists on prolactin blood level in normal and
stressed rats. 48 rats were included in this study ; 24 rats served as control
non stressed rats while the other 24 rats were subjected to acute cold
stress. Each group was subdivided into three subgroups ; a control group,
a group pretreated with a calcium channel blacker (Verapamil) and a
group pretreated with opiate antagonist (naloxone). Acute cold stress
caused a highly significant increase in prolactin level in blood (P<0.001).
Intraperitoneal injection of Verapamil caused a significant increase in pro-
(actin level in non stressed rats (P<0.001) while in stressed rats it cnnsed
a significant decrease in prolactin level (1,1/40.001). In non stressed rats
prolactin level showed no significant change after naloxone injection..
Which, on the other hand caused a significant decrease in prolactin level
in stressed rats (11/40.001) . We conch ide that acute stress can increase
the prolactin level in blood and that calcium ions and opiate peptides play
an important role in the regulation of prolactin release in normal and
stressed rats. |
