Short communicationEffect of ghrelin on regulation of splenic sympathetic nerve discharge

- Ghrelin is an orexigenic hormone that may contribute to neuroimmune interactions.
- Influence of ghrelin on splenic sympathetic nerve discharge (SND) is not known.
- Role of central ghrelin on splenic SND and lumbar SND was investigated.
- Central ghrelin administration produced splenic and lumbar sympathoexcitation.
- Results support a role for central ghrelin in sympathetic-immune interactions.

Ghrelin influences immune system function and modulates the sympathetic nervous system; however, the contribution of ghrelin to neural-immune interactions is not well-established because the effect of ghrelin on splenic sympathetic nerve discharge (SND) is not known. This study tested the hypothesis that central ghrelin administration would inhibit splenic SND in anesthetized rats. Rats received intracerebroventricular (ICV) injections of ghrelin (1 nmol/kg) or aCSF. Lumbar SND recordings provided a non-visceral nerve control. The ICV ghrelin administration significantly increased splenic and lumbar SND, whereas mean arterial pressure (MAP) was not altered. These findings provide fundamental information regarding the nature of sympathetic-immune interactions.