亜鉛欠乏ラットにおける摂食周期とセロトニンに関する研究

抄録

It has been reported that change of serotonin (5HT) secretion in rat brain might induce a periodical change of feed intake in zinc deficient rats. To prove that 5HT is engaged in feeding cycle in Zn deficient rat, agonist and antagonist of 5HT receptors were administered into rat brains in this experiment.

In experiment 1, 8-OH-DPAT was administered into lateral ventricle of zinc deficient rats for 14 days. The 8-OH-DPAT has been known to activate 5HT_1A receptor and suppress 5HT secretion in brain. Periodical change of feed intake due to zinc deficiency didn’t appear while the 8-OH-DPAT was administered, and the periodical change appeared after the 8-OH-DPAT dose ends. This result suggests that 5HT secretion rate in the brains participates in feeding cycle.

In experiment 2, mianserine was administered into lateral ventricle of zinc deficient rats for 14 days since feeding depression in zinc deficiency might be controlled through the 5HT_2C receptor, which has been shown to be involved in suppression of feeding frequency. However, periodical change of feeding rate, which appeared in zinc deficiency, was not disappeared by mianserine dose. Hence it is suggested that 5HT_2C receptor is not involved in regulations of periodical feeding pattern in zinc deficient rats.