Improvement in baroreflex control of renal sympathetic nerve activity in obese Sprague Dawley rats following immunosuppression

Abstract

Obesity induced a renal inflammation and pointed to this being both the origin of autonomic dysregulation and a potential focus for targeted therapy.

Obesity gets on your renal nerves

“…In both studies, rats were subjected to 6–8 weeks of excess fat feeding which led to significantly more weight gain, hypertension, increased glomerular filtration rate and attenuated fractional excretion of Na + . In both studies, there were impaired arterial baroreceptor gain curves for renal sympathetic nerve activity and heart rate that were re‐established by bilateral renal denervation suggesting that renal nerves affect the setpoint of the baroreceptor in obesity . Previous studies of Campese et al .…”

“…The present study takes these previous findings one step further by showing increased plasma and renal tissue level of inflammatory biomarkers in obesity‐related hypertension that were suppressed by tacrolimus but not by denervation. The essential new finding was that immunosuppression by tacrolimus attenuated hypertension and arterial baroreflex impairment similar to, but not additive with, renal denervation after high fat feeding in agreement with but not proving a common pathway . Of note, tacrolimus did not affect baroreflex setting in normotensive control rats and also did not alter baseline blood pressure.…”

“…In the present issue of Acta Physiologica, Khan et al . in their article ‘ Improvement in baroreflex control of renal sympathetic nerve activity in obese Sprague‐Dawley rats following immunosuppression ’ confirm that obesity‐related hypertension involves resetting of the arterial baroreceptor to a state of less sensitivity and relate this mechanistically to inflammation‐induced altered renal afferent nerve activity .…”

“…In the present issue of Acta Physiologica, Khan et al . in their article ‘ Improvement in baroreflex control of renal sympathetic nerve activity in obese Sprague‐Dawley rats following immunosuppression ’ confirm that obesity‐related hypertension involves resetting of the arterial baroreceptor to a state of less sensitivity and relate this mechanistically to inflammation‐induced altered renal afferent nerve activity . Pharmacological treatment with the calcineurin phosphatase inhibitor‐type immunosuppressant tacrolimus attenuated inflammation, reversed, paradoxically, the hypertension and restored baroreceptor sensitivity similar to the effect of renal denervation.…”

“…discriminated between afferent and efferent renal nerve activity in a different renal injury hypertension model where dorsal rhizotomy, with deletion of afferent nerves only, resulted in blood pressure decline. However, this approach was not undertaken in the present study and a direct extrapolation is not possible due to different experimental models . In both studies, a potential contribution of altered function in the low‐pressure baroreceptor reflex was examined using saline infusion to expand extracellular volume.…”