scholarly journals Seasonal variation in the effect of dietary RNA on criteria of energy homoeostasis in the rat

1979 ◽  
Vol 41 (1) ◽  
pp. 183-196
Author(s):  
D. J. Heaf ◽  
D. G. Peers ◽  
J. I. Davies
Keyword(s):  
Fatty Acids ◽  
Nervous System ◽  
Seasonal Variation ◽  
Seasonal Influence ◽  
Dependent Change ◽  
Plasma Ffa ◽  
Sympathetic Nervous ◽  
And Control ◽  
Circulating Levels ◽  
Variable Susceptibility

1. RNA was administered to rats as part of a meal while standardizing food intake and minimizing the effects of psychological stress and diurnal metabolic rhythms. It was demonstrated that circulating levels of glucose and free fatty acids (FFA) in the animals, which were deprived of food for 48 h, were responsive to orally administered caffeine.2. Inclusion of RNA in the diet slightly but consistently reduced the normal postprandial hyperglycaemia. Its effect on plasma FFA was variable although statistically significant in some experiments. The differences between RNA- and control-fed animals were not attributable to differences in the rate of passage of digesta along the gastrointestinal tract.3. Evidence was obtained that the variability in the FFA response was related to a seasonally-dependent change in the state of the animals. The synchronizer (‘Zeitgeber’) responsible for this change was not identified and no satisfactory way of suppressing its effect was found.4. The present findings, taken in conjunction with those of previous workers, suggest that there is a seasonal influence on the sympathetic nervous system manifesting itself as a variable susceptibility to arousal or excitation.

Free fatty acid metabolism in fetal and newborn sheep

1960 ◽  
Vol 199 (6) ◽  
pp. 987-990 ◽  
Author(s):  
C. M. Van Duyne ◽  
H. R. Parker ◽  
R. J. Havel ◽  
L. W. Holm
Keyword(s):  
Fatty Acids ◽  
Nervous System ◽  
Sympathetic Nervous System ◽  
Palmitic Acid ◽  
Newborn Lamb ◽  
Fetal Plasma ◽  
Free Fatty Acid Metabolism ◽  
Plasma Ffa ◽  
Sympathetic Nervous ◽  
Increased Activity

The metabolism of free fatty acids (FFA) was studied in the term ewe, sheep fetus and newborn lamb. The concentration of FFA is about 10 times greater and the concentration of triglyceride fatty acids (TGFA) 2 1/2 times greater in maternal than in fetal plasma. After intravascular administration of palmitic acid-1-C14 complexed to homologous albumin, the initial rates of disappearance of FFA radioactivity from maternal and fetal circulations were similar, with half-times of approximately 2 minutes. Radioactivity appeared in the opposite circulation as FFA indicating that the syndesmochorial placenta is permeable to palmitic acid. Survival of the newborn lamb is associated with a fivefold increase in plasma concentration of FFA and no significant change in glucose or fructose during the first 30 minutes after birth. Failure to survive is associated with lack of increase in plasma FFA concentrations, while glucose concentrations do not differ from those found in surviving lambs. These data suggest that sympathetic nervous system activity is responsible for the FFA elevation and that increased activity of the sympathetic nervous system or FFA mobilization is closely related to survival of the newborn lamb.

Indices of sympathetic activity in the sinoaortic-denervated hypertensive rat

1980 ◽  
Vol 238 (4) ◽  
pp. H521-H526 ◽  
Author(s):  
N. Alexander ◽  
M. T. Velasquez ◽  
M. Decuir ◽  
R. F. Maronde
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Sympathetic Activity ◽  
Wistar Rats ◽  
Adrenal Glands ◽  
Systolic Pressure ◽  
Monoamine Oxidase Activity ◽  
Dopamine Beta Hydroxylase ◽  
Sympathetic Nervous ◽  
Circulating Levels

Blood pressure and circulating levels of norepinephrine (NE), epinephrine (Epi), and dopamine-beta-hydroxylase (DBH) were measured sequentially in sinoaortic-denervated (SAD) Wistar rats and in sham-operated (SO) rats. Systolic tail pressure, plasma NE and E, and plasma DBH all increased significantly within 2 days in SAD rats. In separate studies of rats with indwelling arterial catheters, arterial pressure and plasma NE and DBH were increased in SAD rats in home cages; restraint caused similar increases of pressure and catecholamines in both groups. Systolic pressure remained increased up to 4 mo and plasma DBH for 10 wk in SAD rats; plasma NE and E, however, declined by 3 wk and thereafter remained close to values of SO rats. Additionally, DBH was increased in heart, mesenteric blood vessels and adrenal glands of SAD rats up to 6 wk; tissue monoamine oxidase activity was also increased up to 4 mo. These findings suggest that activation of the sympathetic nervous system initiates and probably sustains hypertension in SAD rats up to 6 wk after operation; thereafter some other mechanism(s) sustains the hypertension.

scholarly journals Obesity, sympathetic nervous system, and hypertension - are they connected?

2006 ◽  
Vol 12 (2) ◽  
pp. 131-140
Author(s):  
A. O. Conrady
Keyword(s):  
Metabolic Syndrome ◽  
Fatty Acids ◽  
Obstructive Sleep Apnea ◽  
Nervous System ◽  
Sleep Apnea ◽  
Sleep Apnea Syndrome ◽  
Sympathetic Hyperactivity ◽  
Obstructive Sleep ◽  
Apnea Syndrome ◽  
Sympathetic Nervous

All known components of metabolic syndrome are related to sympathetic hyperactivity. Sympathetic overactivity participates in genesis oa obesity-related hypertension. The mechanisms include leptin, insulin, free fatty acids as well as obstructive sleep apnea syndrome. Drugs inhibiting sympathetic drive are indicated to such patients.

Abstract 47: Circulating Human Sprr Increased Blood Pressure In Female Mice Fed A Low-fat Diet

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Audrey Poupeau ◽  
Gertrude Arthur ◽  
Kellea Nichols ◽  
Frederique B Yiannikouris
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Humanized Mouse ◽  
Low Fat ◽  
Humanized Mouse Model ◽  
Control Female ◽  
Female Mice ◽  
Low Fat Diet ◽  
Sympathetic Nervous ◽  
And Control

Elevated plasma soluble prorenin receptor (sPRR) is associated with essential hypertension and obesity-hypertension in men. Additionally, our laboratory previously found that the infusion of mouse sPRR elevates systolic blood pressure (SBP) in high-fat (HF) fed male mice through activation of the sympathetic nervous system but did not elevate SBP in HF-fed female mice. Interestingly, mouse sPRR infusion increased renal and hepatic angiotensinogen (AGT) and plasma renin concentration in female mice fed a low-fat diet. However, whether sPRR-activates the renin angiotensin system (RAS) and increases blood pressure in low-fat fed female mice remains to be investigated. Additionally, little is known concerning the influence of human sPRR on blood pressure in women. Therefore, we developed a humanized mouse model with high circulating human sPRR. Human sPRR-Myc-tag transgenic mice were bred with mice expressing Alb/Cre recombinase to induce human sPRR release in the circulation. Control and Alb-HsPRR female mice were fed a LF-diet for 8 months (n=11/groups). Body weight and body composition were examined and blood pressure assessed by radiotelemetry. Human sPRR-Myc-tag was detected in the liver of Alb-HsPRR female mice and plasma sPRR levels increased by 50-fold (CTL: 3.6±0.5 ng/ml, HsPRR:190.5±24.4 ng/ml; P<0.05), which validated the humanized mouse model. Elevated circulating human sPRR did not change body weight (CTL: 22.2±0.37, HsPRR: 23.0±0.32 g) or fat mass (CTL: 2.5±0.2, HsPRR: 3.1±0.2 g). Liver-derived human sPRR significantly elevated SBP in Alb-HsPRR compared to control female mice (Night SBP: CTL: 130.5±1.2 mmHg; Alb-HsPRR: 135.9±2 mmHg; P<0.05) and acute injection of AngII exacerbated SBP elevation. Interestingly, the decrease in blood pressure mediated by losartan was not different between Alb-HsPRR and control female mice (Night ΔSBP: CTL: -13.11±2.2 mmHg; Alb-HsPRR: -14.8±2.7 mmHg; P>0.05). Plasma AGT and renin activity were similar between Alb-HsPRR and control female mice. Therefore, whether the local RAS or the sympathetic nervous system are involved in human sPRR-mediated increase of SBP remains to be examined. Altogether, our results suggest an important role of circulating human sPRR in blood pressure control in women.

Variation of plasma ketones and free fatty acids during acute cold exposure in man

1965 ◽  
Vol 20 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Peter G. Hanson ◽  
Robert E. Johnson
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Cold Exposure ◽  
Ketone Bodies ◽  
Control Period ◽  
Exposure Period ◽  
Nonesterified Fatty Acids ◽  
Acute Cold Exposure ◽  
Plasma Ffa ◽  
And Control

We have studied the magnitude of ketosis induced during acute cold exposure. Plasma and urinary ketone bodies and plasma free fatty acids (FFA) were followed in four healthy young men at rest during a 90-min period of seminude exposure to 0 C in still air. This period was followed by 4 hr of recovery at 25 C. Each subject served as his own control throughout an experimental sequence in which one cold-exposure and corresponding control period (25 C) were experienced each week for 3 successive weeks. The subjects were in a fasting state but with water ad libitum beginning 12 hr prior to the experiment. Light weight clothing was worn during recovery and control periods. The combined group data show a significant increase in plasma FFA during cold exposure as compared with similar control periods. Although true hyperketonemia or hyperketonuria did not develop, the levels of plasma ketones are elevated in the cold-exposure period of the first week. During the second and third week there is no difference between the cold and control plasma ketone concentration. The data suggest that FFA is mobilized as a metabolic substrate during cold exposure and that efficient peripheral utilization of the elevated plasma FFA concentration minimizes hyperketogenesis. ketone bodies; metabolism; nonesterified fatty acids Submitted on April 27, 1964

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