Drinking-induced bradyarrhythmias and cerebral injury in Dahl salt-sensitive rats with sinoaortic denervation.
We have demonstrated that a drinking-induced pressor response was larger if the baroreflex did not operate, and the mean arterial pressure reached 163 mmHg in conscious rats with sinoaortic denervation (SAD). Thus we hypothesized that a drinking behavior became a cardiovascular risk factor if a basal arterial pressure was high. To clarify this, we analyzed the occurrence of arrhythmias and the accumulation of microglia in Dahl salt-sensitive rats (Dahl S) with SAD. We maintained Dahl S and Dahl salt-resistant rats (Dahl R) with a high-sodium diet for 5 weeks. After SAD surgery, we measured arterial pressure and electrocardiogram during water-drinking behavior in all rats. Furthermore, we measured tumor necrosis factor-α concentration in the cerebrospinal fluid (CSF) and microglial accumulations around the third and fourth ventricles in rats with programmed drinking at a rapid or slow rate for 7 days. Incidences of drinking-induced bradyarrhythmias and premature ventricular contractions (PVCs) were significantly larger in Dahl S than Dahl R rats. Both bradyarrhythmias and PVCs were completely abolished by atropine administration. Accumulations of microglia around the third ventricle and increases in TNF-α in the CSF were observed in rats that drank water at a rapid rate; these were not seen in rats that drank water slowly. In conclusion, both cardiovascular events and cerebral injury may be increased by drinking in Dahl S rats with SAD. These risks are reduced by modifying drinking behavior such as slowing the drinking rate.
Department of Physiology, Gifu University Graduate School of Medicine, Gifu, Japan.
Chikara
C
Abe
Hironobu
H
Morita
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001011:Aorta / Q000294:innervation*; D062186:Arterial Pressure; D001285:Atropine / Q000494:pharmacology; D017763:Autonomic Denervation; D017704:Baroreflex; D001919:Bradycardia / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D001930:Brain Injuries / Q000134:cerebrospinal fluid / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D002346:Carotid Sinus / Q000294:innervation*; D004195:Disease Models, Animal; D004326:Drinking; D004327:Drinking Behavior; D004562:Electrocardiography; D006339:Heart Rate; D006973:Hypertension / Q000150:complications* / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D017628:Microglia / Q000473:pathology; D051381:Rats; D020303:Rats, Inbred Dahl; D012307:Risk Factors; D017673:Sodium Chloride, Dietary; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000134:cerebrospinal fluid; D018879:Ventricular Premature Complexes / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control
D000889:Anti-Arrhythmia Agents; D017673:Sodium Chloride, Dietary; D014409:Tumor Necrosis Factor-alpha; D001285:Atropine
Dahl salt-sensitive rat; arterial pressure; bradyarrhythmia; drinking; sinoaortic denervation