Key result
Extraluminal histamine dilates isolated rat intracerebral arterioles to ~139% of control via H2 receptors.
Why the study?
Does histamine cause vasodilation in isolated intracerebral arterioles from rats?
Does histamine cause vasodilation in isolated intracerebral arterioles from rats?
Histamine induces vasodilation of rat intracerebral resistance vessels, an effect that is mediated primarily by H2 receptors.
Answers are grounded in this paper and cite their sources.
No immediate clinical implications; leaves open whether H2-mediated histamine effects translate to human intracerebral arterioles.
Histamine from various sources is found in significant amounts around cerebral vessels and may play a significant role in controlling CBF. The effect of histamine on the intracerebral microcirculation has not been examined. We have used an in vitro technique for the isolation and cannulation of intracerebral arterioles from the rat to study the effect of histamine on the spontaneous tone developed by these vessels. Extraluminally administered histamine caused dose-dependent vasodilation of isolated intracerebral arterioles with a maximal dilation of 139 +/- 2.4% of control diameter. The dilation was blocked by the H2 receptor antagonist cimetidine, but was only incompletely attenuated by the H1 receptor blocker chlorpheniramine. Histamine effects a dilation of the spontaneous tone of intracerebral resistance vessels, which is mediated by H2 receptors.
No takes yet. Share an insight, caveat, or question.
Dacey et al. (1987) studied this question. Histamine vs. Control diameter was evaluated on Vasodilation of isolated intracerebral arterioles. Extraluminally administered histamine caused dose-dependent vasodilation of isolated rat intracerebral arterioles (maximal dilation 139 +/- 2.4% of control), mediated by H2 receptors.
Synapse has enriched 10 related papers. Consider them for comparative context: