title: Long-term high-soybean oil feeding alters regulation of body temperature in rats.
abstract: We investigated whether body temperature (BT) regulatory mechanisms are influenced by dietary fatty acids (FA). Male Wistar rats were fed a high-fat diet containing fish oil (HFD), soybean oil (HSD) or lard (HLD). At the 20-week intervention, the BT of the HSD and HLD groups were lower than that of the normal diet (ND) group in the light and dark periods. The intracerebroventricular injections of interleukin-1β and bombesin in the HSD group induced greater hyperthermia and weaker hypothermia, respectively, than in the ND group. The HSD differentially affected BT under both physiological and pharmacological conditions. In the hypothalamus, the ratio of n-6/n-3 FAs was higher in the HSD group compared with the ND group. DNA microarrays revealed increased expression of thyroid-stimulating hormone β-subunit, and decreased expression of several genes in the hypothalamus of the HSD group compared with the ND group. The HSD feeding increased several adipokine concentrations in the plasma. However, there were no adipokines or gene expressions that changed in only the HSD and HLD groups showing significant hypothermia under the physiological condition. These findings suggested that long-term HSD intake produces abnormal BT regulation. It is less likely that adipokines or proteins/peptides are involved in abnormal BT regulation under the physiological conditions after HSD feeding.
authors.affiliation: Laboratory of Pharmacology, Kinjo Gakuin University College of Pharmacy.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Tsushima
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Yamada
authors.forename: Daisuke
authors.initials: D
authors.lastname: Miyazawa
authors.forename: Mayumi
authors.initials: M
authors.lastname: Mori
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hashimoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Hibino
authors.forename: Harumi
authors.initials: H
authors.lastname: Okuyama
mesh_terms: D054392:Adipokines / Q000097:blood; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects* / Q000235:genetics; D001835:Body Weight / Q000187:drug effects; D001839:Bombesin / Q000494:pharmacology; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism; D005395:Fish Oils / Q000008:administration & dosage / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D053583:Interleukin-1beta / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D017440:Photoperiod; D017208:Rats, Wistar; D013024:Soybean Oil / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D054392:Adipokines; D004041:Dietary Fats; D005227:Fatty Acids; D005395:Fish Oils; D053583:Interleukin-1beta; D013024:Soybean Oil; D001839:Bombesin; C029310:lard