title: Frequency components of systolic blood pressure variability reflect vasomotor and cardiac sympathetic functions in conscious rats.
abstract: In this study, after confirming the suppression of autonomic nervous function by isoflurane anesthesia using autonomic antagonists, we pharmacologically investigated the involvement of vasomotor and cardiac sympathetic functions in systolic blood pressure variability (SBPV) frequency components in conscious rats at rest and during exposure to low-ambient temperature (LT-exposure, 9°C for 90 min). Under unanesthesia, phentolamine administration (α-adrenoceptor antagonist, 10 mg/kg) decreased the mid-frequency component (MF 0.33-0.73 Hz) and inversely increased the high-frequency component (HF 1.3-2.5 Hz). The increased HF was suppressed by subsequent treatment with atenolol (β-adrenoceptor antagonist, 10 mg/kg), but not with atropine (muscarinic receptor antagonist, 10 mg/kg). Moreover, phentolamine administration after atenolol decreased MF, but did not increase HF. LT-exposure increased MF and HF; however, phentolamine pretreatment suppressed the increased MF during LT-exposure, and atenolol pretreatment dose-dependently decreased the increased HF. These results suggest that MF and HF of SBPV may reflect α-adrenoceptor-mediated vasomotor function and β-adrenoceptor-mediated cardiac sympathetic function, respectively, in the conscious state.
authors.affiliation: Department of Algesiology, Aichi Medical University, Nagakute, Aichi 480-1195, Japan. tyos@aichi-med-u.ac.jp
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Eguchi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sakurai
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohmichi
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Mika
authors.initials: M
authors.lastname: Ohmichi
authors.forename: Atsuko
authors.initials: A
authors.lastname: Morimoto
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ushida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwase
authors.forename: Junichi
authors.initials: J
authors.lastname: Sugenoya
authors.forename: Takao
authors.initials: T
authors.lastname: Kumazawa
mesh_terms: D018674:Adrenergic Antagonists / Q000494:pharmacology; D000818:Animals; D001262:Atenolol / Q000494:pharmacology; D001286:Atropine Derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D008297:Male; D010276:Parasympatholytics / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D014666:Vasomotor System / Q000187:drug effects / Q000502:physiology*
chemical_list: D018674:Adrenergic Antagonists; D001286:Atropine Derivatives; D010276:Parasympatholytics; D001262:Atenolol; C006649:methylatropine; D010646:Phentolamine