Abstract
1. 1. We reported previously ( Henwood and Mazurkiewicz-Kwilecki, 1975) that chronic morphine (Mo) administration or Mo withdrawal from Mo dependent rats resulted in a significant decrease in the endogenous histamine (HA) concentration in different brain regions of the rat. 2. 2. Present studies indicated a significant increase in histidine decarboxylase (HD) activity in the hypothalamus and in the cortex of Mo dependent rats. The latter observation is consistent with an increased HA synthesis in these brain regions. 3. 3. Significant increase in HD activity was also noted after Mo withdrawal. 4. 4. Present data produce evidence that HA, the new putative neurotransmitter in the brain, is involved in the mechanism of Mo dependence and Mo withdrawal.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
