Neostigmine in the hippocampus increases thermogenesis and T4-to-T3 conversion

1996 ◽  
Vol 270 (6) ◽  
pp. R1215-R1219 ◽  
Author(s):  
M. Monda ◽  
A. Papa ◽  
G. Brizzi ◽  
B. DeLuca
Keyword(s):  
Firing Rate ◽  
Blood Level ◽  
Sympathetic Nerves ◽  
O2 Consumption ◽  
Saline Injection ◽  
Sprague Dawley ◽  
Interscapular Brown Adipose Tissue ◽  
Sprague Dawley Rats ◽  
Brown Adipose ◽  
Baseline Values

The firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), IBAT and colonic temperatures (TIBAT and TC), and O2 consumption were monitored in urethan-anesthetized male Sprague-Dawley rats. These variables were measured for 40 min before (baseline values) and 40 min after a neostigmine (5 x 10(-7) mol) or saline injection in the hippocampus. The blood level of 3,5,3'-triiodothyronine and L-thyroxine (T3 and T4) and the 5'-deiodinating activity of IBAT, liver, and kidneys were determined in other rats with neostigmine or saline injection. The results showed that neostigmine injection increased firing rate, TIBAT, TC, O2 consumption, blood level of T3, and 5'-deiodinating activity of IBAT. No change was found in the T4 level and in 5'-deiodinating activity of the liver and kidneys. These findings suggest that neostigmine injection in the hippocampus increases heat production by stimulating sympathetic nerves to IBAT and by elevating the blood level of T3.

Lysine acetylsalicylate modifies aphagia and thermogenic changes induced by lateral hypothalamic lesion

1996 ◽  
Vol 271 (6) ◽  
pp. R1638-R1642 ◽  
Author(s):  
M. Monda ◽  
A. Sullo ◽  
E. De Luca ◽  
M. P. Pellicano
Keyword(s):  
Food Intake ◽  
Firing Rate ◽  
Intraperitoneal Injection ◽  
Intraperitoneal Administration ◽  
Sprague Dawley ◽  
Interscapular Brown Adipose Tissue ◽  
Sprague Dawley Rats ◽  
Brown Adipose ◽  
Before And After ◽  
Lysine Acetylsalicylate

These experiments test the effect of intraperitoneal injection of lysine acetylsalicylate on 1) food intake and 2) the sympathetic and thermogenic changes induced by lesion of the lateral hypothalamus (LH). Food intake, firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), and IBAT and colonic temperatures (TIBAT and TC) were monitored in male Sprague-Dawley rats lesioned in the LH. These variables were measured before and after intraperitoneal injection of lysine acetylsalicylate. The same variables were also monitored in 1) lesioned rats with intraperitoneal administration of saline, 2) sham-lesioned animals with intraperitoneal injection of lysine acetylsalicylate, and 3) sham-lesioned rats with intraperitoneal injection of saline. The results show that lysine acetylsalicylate modifies the aphagia by increasing food intake and also reduces the enhancements in firing rate, TIBAT, and TC induced by LH lesion. These findings suggest that prostaglandin synthesis plays a key role in the control of eating behavior in LH-lesioned rats by acting on the sympathetic and thermogenic changes induced by LH lesion.

Lateral hypothalamus and sympathetic firing rate

1988 ◽  
Vol 255 (3) ◽  
pp. R507-R512 ◽  
Author(s):  
T. Sakaguchi ◽  
M. Takahashi ◽  
G. A. Bray
Keyword(s):  
Firing Rate ◽  
Lateral Hypothalamus ◽  
Sympathetic Nerves ◽  
Hypothalamic Area ◽  
Interscapular Brown Adipose Tissue ◽  
Gold Thioglucose ◽  
Brown Adipose ◽  
Bilateral Lesions ◽  
Dose Dependent ◽  
Lowered Body

Measurements of sympathetic firing rate have been made after the acute microinjection of glucose or insulin into the lateral hypothalamic area as well as after ablation of this area with locally injected gold thioglucose. Injection of glucose into the lateral hypothalamus (LH) produced a small but significant and dose-dependent reduction in the firing rate of efferent sympathetic nerves to interscapular brown adipose tissue. Injection of insulin into the same region produced a very short-lived increase in efferent sympathetic firing rate. Bilateral lesions in the lateral hypothalamus produced by microinjection and gold thioglucose lowered body weight more than sham injections into the LH of control animals. There was an increase in basal sympathetic firing rate at 3, 9, and 24 h after LH lesions. There was also an increase in firing rate at 1 and 3 days, but by 7 days firing rate had returned to control levels. The data support the hypothesis that LH lesions enhance sympathetic activity but show only very limited modulation by glucose or insulin.

Brown adipose and metabolic features of chronic diet-induced obesity

1985 ◽  
Vol 248 (6) ◽  
pp. R717-R723 ◽  
Author(s):  
B. E. Levin ◽  
M. Finnegan ◽  
J. Triscari ◽  
A. C. Sullivan
Keyword(s):  
Metabolic Efficiency ◽  
Sprague Dawley ◽  
High Fat ◽  
Interscapular Brown Adipose Tissue ◽  
Diet Induced Obesity ◽  
Sprague Dawley Rats ◽  
Norepinephrine Turnover ◽  
Brown Adipose ◽  
Plasma Insulin Levels

Half of the 3-mo male Sprague-Dawley rats fed a high-fat (DIO) diet for 5 mo became obese and had increased carcass lipid (106%) and plasma insulin levels (61%), despite 8% less total energy intake than chow-fed controls. Their interscapular brown adipose tissue (IBAT) was 52% heavier with 45% more lipid and larger uni- and multilocular cells. Norepinephrine turnover was normal in their hearts, pancreases, and aortas but undetectable in IBAT where in vitro lipolysis, but not O2 consumption (VO2), was enhanced. Half the rats fed the DIO diet ate 17% fewer calories, gained weight equally to controls, but still had 34% more carcass lipid. Their IBAT was heavier, contained 103% more protein, with no detectable norepinephrine turnover, whereas maximal lipolysis was 73% lower and maximal VO2 was the same or even lower than controls. IBAT VO2 was stimulated by switching 8-mo chow-fed controls to the DIO diet for 7 days (which caused a 480% greater weight gain) but not by switching 8-mo obese rats to chow for 3 days. Therefore metabolic efficiency was increased while BAT VO2 and norepinephrine turnover were unchanged or reduced compared with controls by either chronic obesity or a high-fat diet.

Reduced norepinephrine turnover in organs and brains of obesity-prone rats

1995 ◽  
Vol 268 (2) ◽  
pp. R389-R394 ◽  
Author(s):  
B. E. Levin
Keyword(s):  
Energy Content ◽  
Sprague Dawley ◽  
Dorsomedial Nucleus ◽  
Interscapular Brown Adipose Tissue ◽  
Diet Induced Obesity ◽  
Sprague Dawley Rats ◽  
Norepinephrine Turnover ◽  
Brown Adipose ◽  
Lateral Area

One-half of the adult male Sprague-Dawley rats fed a diet relatively high in fat, sucrose, and energy content (HE diet) develop diet-induced obesity (DIO). The rest are diet resistant (DR). The role of peripheral and central norepinephrine (NE) activity in predisposing them to these weight gain patterns was assessed before HE diet exposure. Chow-fed male 3-mo-old Sprague-Dawley rats were separated as being prone to become DIO or DR by their high (3.06 +/- 0.14 micrograms) vs. low (1.17 +/- 0.10 micrograms; P = 0.001) 24-h urine NE output, respectively. Turnover of NE, an index of sympathetic activity, was assessed by synthesis inhibition with alpha-methyl-p-tyrosine. DIO-prone rats had significant 53 and 18% reductions in heart and pancreas NE turnover, with interscapular brown adipose tissue turnover comparable to that of DR-prone rats. Hypothalamic NE turnover was significantly decreased by 85 and 60% in the ventromedial nucleus and lateral area vs. DR-prone rats. Although present in DR-prone rats, no turnover was found in the dorsomedial nucleus of DIO-prone rats. Endogenous NE was reduced by 28% in the paraventricular nucleus, whereas arcuate/median eminence turnover was increased by 100% in DIO-prone rats. Amygdalar NE turnover was similar between phenotypes. These intrinsic differences in NE metabolism may play an important role in the development of DIO on HE diets.

Changes in eating behavior and thermogenic activity following inhibition of nitric oxide formation

1995 ◽  
Vol 268 (6) ◽  
pp. R1533-R1538 ◽  
Author(s):  
B. De Luca ◽  
M. Monda ◽  
A. Sullo
Keyword(s):  
Nitric Oxide ◽  
Oxygen Consumption ◽  
Food Intake ◽  
Firing Rate ◽  
Eating Behavior ◽  
Sympathetic Activity ◽  
Sympathetic Nerves ◽  
No Production ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

The effects of the inhibition of nitric oxide (NO) production on eating behavior and thermogenesis were evaluated in the present experiments. NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO production, was injected intraperitoneally or intracerebroventricularly, and food intake, oxygen consumption rate, and interscapular brown adipose tissue (BAT) temperature were evaluated in conscious rats. The firing rate of sympathetic nerves innervating interscapular BAT was recorded in urethan-anesthetized animals. L-NAME, intraperitoneally injected, decreased food intake, oxygen consumption, temperature, and firing rate of sympathetic nerves innervating interscapular BAT. Intracerebroventricular injection of L-NAME decreased food intake and enhanced oxygen consumption, temperature, and firing rate of sympathetic nerves innervating BAT. The latter changes were similar to those found after lateral hypothalamic lesions. The opposite changes in oxygen consumption, temperature, and sympathetic activity of BAT that followed L-NAME injection through the two different routes were probably due to different effects of the molecule on sympathetic output. Impaired brain production of NO, which followed intracerebroventricular L-NAME, directly increased sympathetic activity, whereas the same activity that followed intraperitoneal L-NAME was depressed by increased blood pressure, which was elicited by the impaired peripheral production of NO.

L-threonine injection into PPC modifies food intake, lateral hypothalamic activity, and sympathetic discharge

1997 ◽  
Vol 273 (2) ◽  
pp. R554-R559 ◽  
Author(s):  
M. Monda ◽  
A. Sullo ◽  
V. De Luca ◽  
M. P. Pellicano ◽  
A. Viggiano
Keyword(s):  
Food Intake ◽  
Firing Rate ◽  
Standard Diet ◽  
Sprague Dawley ◽  
Hypothalamic Neurons ◽  
Interscapular Brown Adipose Tissue ◽  
Lateral Hypothalamic ◽  
Brown Adipose ◽  
Before And After ◽  
Sympathetic Discharge

Food intake and the firing rate of lateral hypothalamic neurons and nerves innervating interscapular brown adipose tissue (IBAT), along with IBAT and colonic temperatures, were monitored in male Sprague-Dawley rats fed a threonine-free diet. These variables were measured before and after a bilateral injection of L-threonine (2 nmol into each side) into the prepiriform cortex (PPC). The same variables were also monitored in 1) rats fed a threonine-free diet and injected with saline, 2) animals fed a standard diet and injected with L-threonine, and 3) rats fed a standard diet and injected with saline. The results showed that injection of L-threonine into PPC increases food intake and firing rate of lateral hypothalamic neurons, whereas it decreases the sympathetic discharge and body temperature in animals fed a threonine-free diet. No changes were found in the animals fed a standard diet. These findings suggest a correlation between 1) threonine level in the PPC and 2) lateral hypothalamic activity and sympathetic discharge to IBAT.

Comparison between two rat sympathetic pathways activated in cold defense

2006 ◽  
Vol 291 (3) ◽  
pp. R589-R595 ◽  
Author(s):  
Youichirou Ootsuka ◽  
Robin M. McAllen
Keyword(s):  
Cold Water ◽  
Relative Sensitivity ◽  
Sympathetic Nerves ◽  
Defense Responses ◽  
Interscapular Brown Adipose Tissue ◽  
Brain Circuits ◽  
Brown Adipose ◽  
Skin Cooling ◽  
Trunk Skin ◽  
Coherence Spectrum

In cold defense and fever, activity increases in sympathetic nerves supplying both tail vessels and interscapular brown adipose tissue (iBAT). These mediate cutaneous vasoconstrictor and thermogenic responses, respectively, and both depend upon neurons in the rostral medullary raphé. To examine the commonality of brain circuits driving these two outflows, sympathetic nerve activity (SNA) was recorded simultaneously from sympathetic fibers in the ventral tail artery (tail SNA) and the nerve to iBAT (iBAT SNA) in urethane-anesthetized rats. From a warm baseline, cold-defense responses were evoked by intermittently circulating cold water through a water jacket around the animal's shaved trunk. Repeated episodes of trunk skin cooling decreased core (rectal) temperature. The threshold skin temperature to activate iBAT SNA was 37.3 ± 0.5°C ( n = 7), significantly lower than that to activate tail SNA (40.1 ± 0.4°C; P < 0.01, n = 7). A fall in core temperature always strongly activated tail SNA (threshold 38.3 ± 0.2°C, n = 7), but its effect on iBAT SNA was absent (2 of 7 rats) or weak (threshold 36.9 ± 0.1°C, n = 5). The relative sensitivity to core vs. skin cooling (K-ratio) was significantly greater for tail SNA than for iBAT SNA. Spectral analysis of paired recordings showed significant coherence between tail SNA and iBAT SNA only at 1.0 ± 0.1 Hz. The coherence was due entirely to the modulation of both signals by the ventilatory cycle because it disappeared when the coherence spectrum was partialized with respect to airway pressure. These findings indicate that independent central pathways drive cutaneous vasoconstrictor and thermogenic sympathetic pathways during cold defense.

Effect of glucose and other hexoses on efferent discharges of brown adipose tissue nerves

1986 ◽  
Vol 251 (2) ◽  
pp. R240-R242 ◽  
Author(s):  
A. Niijima
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Sympathetic Nerves ◽  
Nerve Activity ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis ◽  
Effect Of Glucose

The activity of sympathetic nerves innervating interscapular brown adipose tissue of the rat was recorded. Intravenous administrations of glucose (100-300 mg/kg) enhanced the nerve activity. However, mannose, fructose, or galactose (300 mg/kg) showed no effect, suggesting the response is related to diet-induced thermogenesis in the brown adipose tissue.

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