Hyperlipemic responses induced by centrally administered histamine H1- and H2-receptor agonists in rats.

The H1-receptor agonist 2-pyridylethylamine (PEA), and the H2-receptor agonists dimaprit and impromidine administered intracerebroventricularly (i.c.v.) to conscious rats considerably increased the concentration of free fatty acids (FFA) in the blood serum. The hyperlipemic effect of PEA was abolished by mepyramine, a H1-receptor antagonist. Responses to dimaprit and impromidine were not antagonized by cimetidine. These results suggest that central H1-receptor stimulation elicits the hyperlipemic responses in rats. The role of central H2-receptors in this reaction is not clear.