title: A high-salt diet further impairs age-associated declines in cognitive, behavioral, and cardiovascular functions in male Fischer brown Norway rats.
abstract: Aging-associated declines in cognitive, emotional, and cardiovascular function are well known. Environmental stress triggers critical changes in the brain, further compromising cardiovascular and behavioral health during aging. Excessive dietary salt intake is one such stressor. Here, we tested the effect of high salt (HS) on anxiety, learning-memory function, and blood pressure (BP) in male Fischer brown Norway (FBN) rats. Adult (A; 2 mo) and old (O; 20 mo) male rats were fed normal-salt (NS; 0.4% NaCl) or HS (8% NaCl) diets for 4 wk after being implanted with telemeter probes for conscious BP measurement. Thereafter, tests to assess anxiety-like behavior and learning-memory were conducted. The rats were then killed, and samples of plasma, urine, and brain tissue were collected. We found that systolic BP was higher in O-NS (117 ± 1.2 mm Hg) than in A-NS (105 ± 0.8 mm Hg) rats (P < 0.05). Furthermore, BP was higher in O-HS (124 ± 1.4 mm Hg) than in O-NS (117 ± 1.2 mm Hg) rats (P < 0.05). Moreover, anxiety-like behavior (light-dark and open-field tests) was not different between A-NS and O-NS rats but was greater in O-HS rats than in A-NS, O-NS, or A-HS rats (P < 0.05). Short-term memory (radial arm water maze test) was similar in A-NS and O-NS rats but was significantly impaired in O-HS rats compared with A-NS, O-NS, or A-HS rats (P < 0.05). Furthermore, oxidative stress variables (in plasma, urine, and brain) as well as corticosterone (plasma) were greater in O-HS rats when compared with A-NS, O-NS, or A-HS rats (P < 0.05). The antioxidant enzyme glyoxalase-1 expression was selectively reduced in the hippocampus and amygdala of O-HS rats compared with A-NS, O-NS, or A-HS rats (P < 0.05), whereas other antioxidant enzymes, glutathione reductase 1, manganese superoxide dismutase (SOD), and Cu/Zn SOD remained unchanged. We suggest that salt-sensitive hypertension and behavioral derangement are associated with a redox imbalance in the brain of aged FBN rats.
authors.affiliation: Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX, USA.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Chugh
authors.forename: Mohammad
authors.initials: M
authors.lastname: Asghar
authors.forename: Gaurav
authors.initials: G
authors.lastname: Patki
authors.forename: Ritu
authors.initials: R
authors.lastname: Bohat
authors.forename: Faizan
authors.initials: F
authors.lastname: Jafri
authors.forename: Farida
authors.initials: F
authors.lastname: Allam
authors.forename: An T
authors.initials: AT
authors.lastname: Dao
authors.forename: Christopher
authors.initials: C
authors.lastname: Mowrey
authors.forename: Karim
authors.initials: K
authors.lastname: Alkadhi
authors.forename: Samina
authors.initials: S
authors.lastname: Salim
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000375:Aging; D000818:Animals; D001007:Anxiety / Q000503:physiopathology; D001794:Blood Pressure; D003345:Corticosterone / Q000097:blood; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D004032:Diet; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D005980:Glutathione Reductase / Q000378:metabolism; D006973:Hypertension / Q000503:physiopathology; D007791:Lactoylglutathione Lyase / Q000378:metabolism; D007858:Learning; D008297:Male; D008570:Memory, Short-Term; D018384:Oxidative Stress; D051381:Rats; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000009:adverse effects*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D017673:Sodium Chloride, Dietary; C075750:8-epi-prostaglandin F2alpha; D000080242:8-Hydroxy-2'-Deoxyguanosine; D015237:Dinoprost; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D007791:Lactoylglutathione Lyase; D003849:Deoxyguanosine; D003345:Corticosterone