Release of noradrenaline from brown fat of cold-acclimated rats

Cottle, W. H.; Nash, Charles W.; Veress, A. T.; Ferguson, Bruce

doi:10.1016/0024-3205(67)90034-3

Cited by 36 publications

(6 citation statements)

References 8 publications

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“…It was noted that NA level in BAT was about 60 lower (p < 0.01) in CA than in NSWC (Table 1). CoTTLE et al (1967) reported that BAT from cold-acclimated rat had a greater concentration of NA than that from the warm controls, while in other studies (KENNEDY et al, 1977;LAURY et a!., 1982;YOUNG et al, 1982) BAT NA levels seemed not to be significantly changed by cold acclimation. Although such discrepancies in the endogenous NA concentrations of BAT in the cold-acclimated rats remains obscure, it has been unanimously evidenced that cold acclimation increases NA turnover of BAT.…”

Section: Discussionmentioning

confidence: 82%

Effects of cold and immobilization stress on noradrenaline turnover in brown adipose tissue of rat.

1987

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Noradrenaline (NA) turnover of the interscapular brown adipose tissue (BAT) was determined in order to evaluate a role of sympathetic NA of this tissue in an enhanced nonshivering thermogenesis which had been previously evidenced in the repetitively stressed rats by immobilization (daily 3-h immobilization for 4 weeks) and the coldacclimated ones (5°C, 4 weeks). The disappearance rate of NA from the BAT following blockade of NA synthesis with a-methyl p-tyrosine was adopted for estimation of NA turnover of the tissue. Cold acclimation increased both fractional turnover rate (% /h) (k) and turnover rate (ngf (g BAT . h)). Repetitive immobilization stress also elevated turnover rate, but not k. In the warm non-stressed controls acute cold exposure to -5°C and acute immobilization stress elevated the turnover rate. The effect of cold exposure was significantly greater than that of immobilization stress for both indices of NA turnover. In the cold-acclimated rats acute cold exposure increased k as well as turnover rate, but not acute immobilization stress. In the repetitively immobilized rats both acute cold exposure and acute immobilization stress elevated k and turnover rate. These results indicate that immobilization enhances sympathetic activity of thermogenic tissue, BAT. The results also suggest that the extent of sympathetic participation is not necessarily the same between the cold-acclimated and the stressed rats.

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Section: Discussionmentioning

confidence: 82%

Effects of cold and immobilization stress on noradrenaline turnover in brown adipose tissue of rat.

1987

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“…[Roberts and Smith. 1967], and increases in the specific activity of respirato ry enzymes [Barnard el al., 1970] and in the concentration and turnover of noradrenalin [Cottle et al, 1967]. Thus, the cold-induced increment in re spiratory capacity of the tissue is achieved both by increase in specific respir atory activity and by increase in mass of the tissue relative to body weight.…”

Section: Discussionmentioning

confidence: 99%

The Effects of Ambient Temperature on the Fasted Newborn Rabbit II.

Cardasis¹,

Blanc²,

Sinclair³

1972

Neonatology

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“…Moreover, CPZ inhibited noradrenaline-stimulated lipolysis in IBAT and EWAT of cold-acclimated rats and the effect on IBAT was more evident than that on EWAT. After cold acclimation, the cate cholamine concentration in brown adipose tissue increases (25), the density of catechol aminergic nerve terminals is also prominent (24,25) and the release of noradrenaline from nerve terminals is enhanced (32). These are all signs of the elevated sympathetic activity.…”

Section: Fig 4 Effects Of Chlorpromazine On the Noradrenaline-inducmentioning

confidence: 98%

Effects of Chlorpromazine on Lipolysis in Brown and White Adipose Tissues of Cold-Exposed Rats

Uchida

1979

Japanese Journal of Pharmacology

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Abstract-Effectsof chlorpromazine (CPZ) on lipolysis in brown (interscapular: IBAT) and white (epididymal: EWAT) adipose tissues in cold-exposed rats were studied in vitro. Adult male Wistar-Imamichi rats were exposed to 4°C for 1 (acute cold-exposed) or 30 (cold-acclimated) days. The spontaneous free fatty acid (FFA) release from interscapular brown adipose tissue (IBAT) of control rats, was three fold higher than epididymal white adipose tissue (EWAT). FFA release from the EWAT of acute cold-exposed rats was significantly higher than that of control rats. After cold ac climation, FFA release from IBAT increased up to three times that of the control level. CPZ (10-', 10-3 M) suppressed the elevated lipolytic activity in IBAT of cold acclimated rats. However CPZ had no effect on FFA release from EWAT or IBAT in all other groups. A single intravenous administration of 10 mg/kg 6-hydroxy dopamine (6-OHDA) produced a marked decrease in the concentration of noradrenaline and dopamine in MAT and EWAT of cold-acclimated rats. FFA release from IBAT in 6-OHDA treated, cold-acclimated rats decreased to 50 % of untreated, cold-acclimated rats. A further decrease in lipolytic activity in the IBAT of 6-OHDA treated, cold-acclimated rats was produced following CPZ treatment. CPZ also depressed the lipolysis stimulated by the added noradrenaline (3 x 10-5 M). These results suggest that the effect of CPZ on the lipolysis in the IBAT from cold-acclimated rats is mediated by a modification of sympathetic activity.It is now generally accepted that the sympathetic nervous system plays an important role in the mobilization of free fatty acids (FFA) from adipose tissues.In particular, brown adipose tissue which is hypertrophied in cold-acclimated animals (1, 2) is intensively in nervated with sympathetic nerves in comparison to the white adipose tissue (3). The function of brown adipose tissue is to produce heat responding to the cold-stimulated release of noradrenaline from sympathetic nerve endings within the tissue (4-6). Free fatty acids following the augmented lipolysis may serve as essential substrates for thermogenesis in cold environments (7). A number of agents have been shown to inhibit lipolysis by inter fering with steps in the lipolytic process. Previous work has shown that chlorpromazine (CPZ) inhibits noradrenaline induced in vitro lipolysis in the rat epididymal fat (8). In vivo, CPZ also increases plasma FFA level (9, 10).We previously found that removal of interscapular brown adipose tissue (IBAT) po tentiated the hypothermia induced by CPZ injection in the cold-acclimated rats (11). This finding indicated that IBAT is involved in the CPZ induced hypothermia in the cold acclimated rat. Therefore, the following experiments were undertaken to determine the effects of CPZ on the stimulated lipolysis of adipose tissue which occurs during the cold exposure.Effects of chlorpromazine on the in vitro lipolysis were studied in the brown and white adipose tissues from control, acute cold-exposed and cold-acclimated rats. MAT...

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Release of noradrenaline from brown fat of cold-acclimated rats

Cited by 36 publications

References 8 publications

Effects of cold and immobilization stress on noradrenaline turnover in brown adipose tissue of rat.

Effects of cold and immobilization stress on noradrenaline turnover in brown adipose tissue of rat.

The Effects of Ambient Temperature on the Fasted Newborn Rabbit II.

Effects of Chlorpromazine on Lipolysis in Brown and White Adipose Tissues of Cold-Exposed Rats

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