Effect of ovarian hormones on mitochondrial enzyme activity in the fat oxidation pathway of skeletal muscle

2001 ◽  
Vol 281 (4) ◽  
pp. E803-E808 ◽  
Author(s):  
S. E. Campbell ◽  
M. A. Febbraio

To examine the roles of 17β-estradiol (E2) and progesterone (Prog) in lipid metabolism, skeletal muscle enzyme activities were studied in female Sprague-Dawley rats. Groups included sham-operated rats (C) and ovariectomized rats treated with placebo (O), E2 (E), Prog (P), both hormones at physiological doses (P + E), or both hormones with a high dose of E2 (P + HiE). Hormone (or vehicle only) delivery was via time-release pellets inserted at the time of surgery, 15 days before metabolic testing. Results demonstrated that carnitine palmitoyltransferase maximal activity was 19, 21, and 19% lower ( P < 0.01) in O, P, and P + E rats, respectively, compared with C rats. Conversely, activity in E and P + HiE rats was 14 and 19% higher ( P < 0.01) than in C. β-Hydroxyacyl-CoA dehydrogenase (β-HAD) maximal activity was 20% lower ( P < 0.01) in O than in C rats; similarly, P and P + E rats were 18 and 19% lower, respectively ( P < 0.01); however, treatment with E2returned β-HAD activity to C levels. These results suggest that E2 plays a role in lipid metabolism by increasing the maximal activity of key enzymes in the fat oxidative pathway of skeletal muscle.

2002 ◽  
Vol 282 (5) ◽  
pp. E1139-E1146 ◽  
Author(s):  
S. E. Campbell ◽  
M. A. Febbraio

This study examined the roles of the female sex steroids, 17β-estradiol (E2) and progesterone (Prog), on glucose uptake and GLUT4 protein expression. Female Sprague-Dawley rats were either sham operated (C) or ovariectomized and treated with placebo (O), E2 (E), Prog (P), or both hormones at physiological doses (P + E) or the same dose of Prog with a high dose of E2 (P + HiE) via timed-release pellets inserted at the time of surgery, 15 days before metabolic testing. On the morning of day 15, animals received a 300-μCi injection (ip) of 2-deoxy-[14C]glucose and then either exercised on a motorized treadmill for 30 min at 0.35 m/s or remained sedentary in their cages for the same period. Basal glucose uptake was not different between the treatment groups in either the red or white quadriceps. However, glucose uptake was decreased ( P < 0.05) in O, P, and P + E rats during exercise in the red quadriceps compared with C rats, whereas E and P + HiE treatment restored glucose uptake. Glycogen content in skeletal muscle followed similar trends, with no differences seen in resting animals. Postexercise red quadriceps glycogen levels were higher ( P < 0.05) in the E and P + HiE rats compared with O and P. Treatment of ovariectomized rats with progesterone (P rats) decreased ( P < 0.05) GLUT4 content in the red quadriceps by 21% compared with C rats. These data demonstrate that estrogen-deficient animals have a decreased ability for contraction-stimulated glucose uptake and increased glycogen use during aerobic exercise. However, changes in contraction-stimulated glucose uptake could not be explained by altered transporter protein content, since the absence of E2 had no effect on GLUT4 protein.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
D. Saul ◽  
J. H. Kling ◽  
R. L. Kosinsky ◽  
D. B. Hoffmann ◽  
M. Komrakova ◽  
...  

Sarcopenia, a loss of muscle mass accompanying osteoporosis, leads to falls and fall-related injuries. Baicalein, as a phytochemical agent, has an antioxidative and anti-inflammatory effect in muscle. In this study, sixty-one female Sprague Dawley rats were divided into five groups: four groups were ovariectomized (OVX) and one control group was nonovariectomized (NON-OVX). Eight weeks after ovariectomy, three disparate concentrations (1 mg/kg body weight (BW), 10 mg/kg BW, and 100 mg/kg BW) of baicalein were applied subcutaneously daily in three OVX groups. Mm. soleus, gastrocnemius, and longissimus were extracted; their diameter, area, relation to body, and muscle weights as well as number of capillaries per fibre were recorded. In Mm. soleus and gastrocnemius, the baicalein effect (increasing number of capillaries per fibre) was proportional to the dose applied. The fibre diameters and area under baicalein treatment were significantly greater compared to OVX and NON-OVX groups. In M. longissimus, we observed a shift to type IIa fibres. Serum creatine kinase levels were significantly lower in highest baicalein concentration group. We conclude that baicalein can stimulate angiogenesis, though not fibre type-specific, in skeletal muscle and reduce the estrogen-related loss of fibre diameter and area in the skeletal muscle in rats. Therefore, a protective effect of baicalein on muscle cells can be assumed.


1999 ◽  
Vol 77 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Yunlong Zhang ◽  
Sandra T Davidge

The effect of estrogen on the passive characteristics of arteries is not known. We hypothesized that estrogen would increase arterial distensibility as part of its protective effect on the vasculature. Female Sprague-Dawley rats were ovariectomized at 11 weeks of age. One group received a placebo (n = 6), while two other groups (n = 5 each) of rats received a 17β-estradiol pellet (0.15 mg or 0.5 mg with 60-day release). After 4 weeks of estrogen replacement, coronary and mesenteric arteries (<200 µm diameter) were dissected and mounted on a dual-chamber arteriograph. Lumen diameter and wall thickness were measured in pressurized arteries. The relative changes in diameter (distensibility) as well as wall thickness per unit change in pressure were significantly increased (p < 0.05) in the coronary arteries of the 0.5 mg estradiol replaced rats compared with the ovariectomized control animals and the 0.15 mg estradiol replaced rats. Surprisingly, in the mesenteric arteries from the same animals, there was no difference in distensibility or pressure - wall thickness among the groups. This study provides experimental data of a novel hypothesis that estrogen may afford part of its protection through vascular remodeling of the coronary circulation.Key words: vasculature, remodeling, cardiovascular disease.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Mohamed Saleem Abdul Shukkoor ◽  
Mohamad Taufik Hidayat Bin Baharuldin ◽  
Abdul Manan Mat Jais ◽  
Mohamad Aris Mohamad Moklas ◽  
Sharida Fakurazi ◽  
...  

Postpartum depression affects 15% of women.Channa striatus, a freshwater fish, is consumed in local Malay population as a rejuvenating diet during postpartum period. This study evaluated the antidepressant-like effect of lipid extract ofC. striatusfillet and its mechanism of action in female Sprague-Dawley rats in postpartum model of depression. The rats were ovariectomized and treated with high dose of progesterone and estradiol benzoate for 23 days to have hormone-simulated pregnancy. The day 24 and afterwards were considered as the postpartum period. During the postpartum period, lipid extract was administered at 125, 250, and 500 mg/kg through intraperitoneal route for 15 days. Fluoxetine (10 mg/kg) was used as the positive control. On postpartum day 15, the animals were tested in forced swimming test (FST) and open field test (OFT) followed by biochemical analysis. Withdrawal of hormone administration during the postpartum period induced depressive-like behavior in FST. Administration of lipid extract reversed that depressive-like behavior at 125, 250, and 500 mg/kg in FST. In OFT, it decreased the exploratory activity. The mechanism of the antidepressant-like effect may be mediated through the decrease in plasma corticosterone, increase in plasma oxytocin, and decrease in nuclear factor-kappa B in prefrontal cortex of rats.


2021 ◽  
Vol 12 (2) ◽  
pp. 1272-1275
Author(s):  
Angu Bala Ganesh K S V ◽  
Sujeet Shekhar Sinha ◽  
Kesavi Durairaj ◽  
Abdul Sahabudeen K

Naphthalene is a bicyclic aromatic constituent commonly used in different domestic and marketable applications comprising soil fumigants, lavatory scent disks and mothballs. Accidentally, workers, children and animals are exposed to naphthalene mothballs, so there is a need to study the pathology behind this chemical toxicity. The current study was carried out to assess the ultra structural changes of basolateral amygdaloid nuclei in the Sprague Dawley rats brain in association to naphthalene toxicity. The toxicity model group was administered with naphthalene (200 and 400mg) using corn oil as a vehicle for 28 days. The post delayed toxicity of naphthalene high dose ingestion was also assessed in rats. After the experimental period, the brain tissue was processed to observe the ultra structural changes using a transmission electron microscope. The alterations in cell organelles, nuclei damage, mitochondrial swelling, chromatin condensation suggested naphthalene induced damage in the neurons of the basolateral amygdala of the brain in the toxicity model group. These experimental trials provide information about the alert of mothball usage in the home and identify risks linked with accidental exposure and misuse.


2001 ◽  
Vol 91 (4) ◽  
pp. 1828-1835 ◽  
Author(s):  
Nicole Stupka ◽  
Peter M. Tiidus

The effects of estrogen and ovariectomy on indexes of muscle damage after 2 h of complete hindlimb ischemia and 2 h of reperfusion were investigated in female Sprague-Dawley rats. The rats were assigned to one of three experimental groups: ovariectomized with a 17β-estradiol pellet implant (OE), ovariectomized with a placebo pellet implant (OP), or control with intact ovaries (R). It was hypothesized that following ischemia-reperfusion (I/R), muscle damage indexes [serum creatine kinase (CK) activity, calpain-like activity, inflammatory cell infiltration, and markers of lipid peroxidation (thiobarbituric-reactive substances)] would be lower in the OE and R rats compared with the OP rats due to the protective effects of estrogen. Serum CK activity following I/R was greater ( P < 0.01) in the R rats vs. OP rats and similar in the OP and OE rats. Calpain-like activity was greatest in the R rats ( P < 0.01) and similar in the OP and OE rats. Neutrophil infiltration was assessed using the myeloperoxidase (MPO) assay and immunohistochemical staining for CD43-positive (CD43+) cells. MPO activity was lower ( P < 0.05) in the OE rats compared with any other group and similar in the OP and R rats. The number of CD43+ cells was greater ( P < 0.01) in the OP rats compared with the OE and R rats and similar in the OE and R rats. The OE rats had lower ( P < 0.05) thiobarbituric-reactive substance content following I/R compared with the R and OP rats. Indexes of muscle damage were consistently attenuated in the OE rats but not in the R rats. A 10-fold difference in serum estrogen content may mediate this. Surprisingly, serum CK activity and muscle calpain-like activity were lower ( P< 0.05) in the OP rats compared with the R rats. Increases in serum insulin-like growth factor-1 content ( P < 0.05) due to ovariectomy were hypothesized to account for this finding. Thus both ovariectomy and estrogen supplementation have differential effects on indexes of I/R muscle damage.


Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1882 ◽  
Author(s):  
Roy Skinner ◽  
Derek Warren ◽  
Soofia Lateef ◽  
Vagner Benedito ◽  
Janet Tou

Apple pomace, which is a waste byproduct of processing, is rich in several nutrients, particularly dietary fiber, indicating potential benefits for diseases that are attributed to poor diets, such as non-alcoholic fatty liver disease (NAFLD). NAFLD affects over 25% of United States population and is increasing in children. Increasing fruit consumption can influence NAFLD. The study objective was to replace calories in standard or Western diets with apple pomace to determine the effects on genes regulating hepatic lipid metabolism and on risk of NAFLD. Female Sprague-Dawley rats were randomly assigned (n = 8 rats/group) to isocaloric diets of AIN-93G and AIN-93G/10% w/w apple pomace (AIN/AP) or isocaloric diets of Western (45% fat, 33% sucrose) and Western/10% w/w apple pomace (Western/AP) diets for eight weeks. There were no significant effects on hepatic lipid metabolism in rats fed AIN/AP. Western/AP diet containing fiber-rich apple pomace attenuated fat vacuole infiltration, elevated monounsaturated fatty acid content, and triglyceride storage in the liver due to higher circulating bile and upregulated hepatic DGAT2 gene expression induced by feeding a Western diet. The study results showed the replacement of calories in Western diet with apple pomace attenuated NAFLD risk. Therefore, apple pomace has the potential to be developed into a sustainable functional food for human consumption.


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