scholarly journals Variation in tissue carnitine concentrations with age and sex in the rat

1978 ◽  
Vol 176 (3) ◽  
pp. 677-681 ◽  
Author(s):  
Peggy R. Borum
Keyword(s):  
Skeletal Muscle ◽  
Adult Male ◽  
Human Subject ◽  
The Body ◽  
Female Rats ◽  
Male Rats ◽  
Adult Females ◽  
Weanling Rats ◽  
Carnitine Metabolism ◽  
Carnitine Concentration

Diabetes, starvation and various hormonal treatments are known to alter drastically carnitine concentrations in the body. Before the mechanisms controlling carnitine metabolism could be determined, it was necessary to establish normal carnitine concentrations in both sexes at different ages. Carnitine was assayed in plasma, liver, heart and skeletal muscle of rats from birth to weaning. The plasma carnitine increased rapidly during the first 2 days after birth. Carnitine in both heart and skeletal muscle increased, whereas liver concentrations declined during the first week of life. A carnitine-free diet containing sufficient precursors for carnitine biosynthesis was fed to weanling rats. Groups of ten male and ten female rats were killed each week for 10 consecutive weeks. Carnitine was determined in plasma, liver, heart, skeletal muscle, urine and epididymis in the male. There was no difference in carnitine concentrations between the sexes at weaning. Plasma, heart and muscle concentrations were higher in adult male rats than in adult females. However, liver carnitine and urinary carnitine concentrations were higher in adult female than in adult male rats. The epididymal carnitine concentration increased very rapidly during 50 to 70 days of age and the differences in carnitine concentrations between the sexes also became apparent during this time. Thus both the age and the sex of the human subject or experimental animal must be considered when investigating carnitine metabolism.

Insulin sensitivity, leptin, adiponectin, resistin, and testosterone in adult male and female rats after maternal-neonatal separation and environmental stress

2018 ◽  
Vol 314 (1) ◽  
pp. R12-R21 ◽  
Author(s):  
Hershel Raff ◽  
Brian Hoeynck ◽  
Mack Jablonski ◽  
Cole Leonovicz ◽  
Jonathan M. Phillips ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adult Male ◽  
Rat Model ◽  
Female Rats ◽  
Male Rats ◽  
Male And Female ◽  
Neonatal Hypoxia ◽  
Male And Female Rats ◽  
Plasma Leptin ◽  
Neonatal Separation

Care of premature infants often requires parental and caregiver separation, particularly during hypoxic and hypothermic episodes. We have established a neonatal rat model of human prematurity involving maternal-neonatal separation and hypoxia with spontaneous hypothermia prevented by external heat. Adults previously exposed to these neonatal stressors show a sex difference in the insulin and glucose response to arginine stimulation suggesting a state of insulin resistance. The current study used this cohort of adult rats to evaluate insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR)], plasma adipokines (reflecting insulin resistance states), and testosterone. The major findings were that daily maternal-neonatal separation led to an increase in body weight and HOMA-IR in adult male and female rats and increased plasma leptin in adult male rats only; neither prior neonatal hypoxia (without or with body temperature control) nor neonatal hypothermia altered subsequent adult HOMA-IR or plasma adiponectin. Adult male-female differences in plasma leptin were lost with prior exposure to neonatal hypoxia or hypothermia; male-female differences in resistin were lost in the adults that were exposed to hypoxia and spontaneous hypothermia as neonates. Exposure of neonates to daily hypoxia without spontaneous hypothermia led to a decrease in plasma testosterone in adult male rats. We conclude that neonatal stressors result in subsequent adult sex-dependent increases in insulin resistance and adipokines and that our rat model of prematurity with hypoxia without hypothermia alters adult testosterone dynamics.

Acute and sub-chronic toxicity of the aqueous extract of Ficus vogelii (Miq.) Miq. stem bark in rats

2021 ◽  
Vol 10 (2) ◽  
pp. 89-97
Author(s):  
EL Lappa ◽  
◽  
C Bogning Zangueu ◽  
EL Nguemfo ◽  
JJ Kojom Wanche ◽  
...  
Keyword(s):  
Body Weight ◽  
Aqueous Extract ◽  
Chronic Toxicity ◽  
Hematological Parameters ◽  
Lethal Dose ◽  
Relative Weight ◽  
Stem Bark ◽  
The Body ◽  
Female Rats ◽  
Male Rats

Ficus vogelii is a medicinal plant mainly found in tropical Africa and reported to treat inflammatory complaints. This study aims to evaluate the acute and sub-chronic toxicity of the aqueous extract of Ficus vogelii stem bark in wistar rats. For acute study, aqueous extract at a single dose of 5000 mg/kg body weight was administered to female rats and observed for 14 days. In the sub-chronic study, the extract was administered daily to both sex rats at the doses of 100, 200, 400, and 600 mg/kg body weight for 28 consecutive days. Body weight was measured weekly, while hematological, biochemical, and histopathological parameters were analyzed after euthanize. Aqueous extract of Ficus vogelii at all tested doses didn’t produced any mortality or significant change on the body weight and relative weight of rats on acute and sub-chronic studies. The lethal dose 50 was estimated greater than 5000 mg/kg (DL50˃5000 mg/kg). Hematological parameters were recorded non-significant in all treated rats. Aqueous extract at 600 mg/kg significantly changed transaminases and alkaline phosphatase activities, these changes were reversible in satellites. The concentrations of bilirubin was increased at 200 and 600 mg/kg in male rats, at 100, 400 mg/kg in female rats. The levels of lipids markers didn’t changed, except the significant decrease of LDL-cholesterol. Histological examination didn’t showed any change in the architecture of the liver and kidney of rats treated compared to control. Thus aqueous extract of Ficus vogelii stem bark didn’t produced adverse effects in rats after oral acute and sub-chronic treatment.

PROLACTIN STIMULATION TEST WITH PERPHENAZINE: AN EVALUATION OF PLASMA PROLACTIN LEVELS AND PITUITARY SECRETORY ACTIVITY IN THE RAT

1976 ◽  
Vol 68 (3) ◽  
pp. 355-368 ◽  
Author(s):  
A. A. VAN DER GUGTEN ◽  
P. C. SAHULEKA ◽  
G. H. VAN GALEN ◽  
H. G. KWA
Keyword(s):  
Adult Male ◽  
Secretory Activity ◽  
Female Rats ◽  
Male Rats ◽  
Plasma Prolactin ◽  
Prolactin Release ◽  
Oestrogen Treatment ◽  
Endocrine Status ◽  
Pituitary Prolactin ◽  
Single Plasma

SUMMARY Many investigations of the regulation of prolactin synthesis and release are based on single plasma prolactin determinations. The purpose of the present experiment was to ascertain whether groups of rats (i.e. young or adult, male or female animals, being either intact, gonadectomized or gonadectomized and treated with oestrone), differing in age and/or endocrine status, will react to a single dose of perphenazine by an acute release of pituitary prolactin in proportion to their initial plasma prolactin levels. No consistent relation existed between the classification of the twelve groups of rats into three categories of basal plasma prolactin levels (i.e. < 20, 25–50, > 125 ng/ml) and their response to perphenazine. Even though all groups showed a highly significant increase of plasma prolactin levels the magnitude of the maximum prolactin response at 30 min varied greatly within the groups of one category and thus was not related to the initial prolactin levels. The effect of 14 days of oestrone treatment in increasing plasma prolactin levels in gonadectomized animals was greatest in young and adult male rats, less in young females and not significant in adult females. The results obtained after perphenazine treatment in the latter group made it clear that the effect of oestrogen treatment on prolactin release can be completely blocked by increasing synthesis and/or release of the prolactin-release inhibiting factor (PIF). Since perphenazine induces decrease of pituitary prolactin and a concomitant increase of plasma prolactin levels through lowered PIF-action, the positive effect of oestrogens on prolactin release (as observed in gonadectomized male and young female rats) apparently is caused by a different mode of action. The implications of these findings for the regulation of prolactin release, as affected by the endocrine status of the rat, is discussed. Moreover, comparison of prolactin lost from the pituitary and gained in the circulation of the experimental animals, with amounts of prolactin that were observed to disappear from plasma during the experiment, provided suggestive evidence that the capacity to synthesize and/or eliminate prolactin, after a sudden provoked release of the hormone, differed among the groups. The rates of synthesis by the pituitary, of release from the pituitary into the circulation as well as of elimination of the hormone from the circulation (equally involved in determining actual plasma levels) are thought, therefore, to be far more important for the elucidation of prolactin regulation than single plasma prolactin determinations.

Acute and chronic effects of alcohol exposure on skeletal muscle c-myc, p53, and Bcl-2 mRNA expression

2003 ◽  
Vol 285 (6) ◽  
pp. E1273-E1281 ◽  
Author(s):  
Tatsuo Nakahara ◽  
Kijiro Hashimoto ◽  
Makoto Hirano ◽  
Michael Koll ◽  
Colin R. Martin ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Internal Standard ◽  
Alcohol Exposure ◽  
Female Rats ◽  
Male Rats ◽  
Skeletal Muscle Atrophy ◽  
Muscle Pathology ◽  
Mrna Levels ◽  
Male And Female Rats

Skeletal muscle atrophy is a common feature in alcoholism that affects up to two-thirds of alcohol misusers, and women appear to be particularly susceptible. There is also some evidence to suggest that malnutrition exacerbates the effects of alcohol on muscle. However, the mechanisms responsible for the myopathy remain elusive, and some studies suggest that acetaldehyde, rather than alcohol, is the principal pathogenic perturbant. Previous reports on rats dosed acutely with ethanol (<24 h) have suggested that increased proto-oncogene expression (i.e., c-myc) may be a causative process, possibly via activating preapoptotic or transcriptional pathways. We hypothesized that 1) increases in c-myc mRNA levels also occur in muscle exposed chronically to alcohol, 2) muscle of female rats is more sensitive than that from male rats, 3) raising acetaldehyde will also increase c-myc, 4) prior starvation will cause further increases in c-myc mRNA expression in response to ethanol, and 5) other genes involved in apoptosis (i.e., p53 and Bcl-2) would also be affected by alcohol. To test this, we measured c-myc mRNA levels in skeletal muscle of rats dosed either chronically (6–7 wk; ethanol as 35% of total dietary energy) or acutely (2.5 h; ethanol as 75 mmol/kg body wt ip) with ethanol. All experiments were carried out in male Wistar rats (∼0.1–0.15 kg body wt) except the study that examined gender susceptibility in male and female rats. At the end of the studies, rats were killed, and c-myc, p53, and Bcl-2 mRNA was analyzed in skeletal muscle by RT-PCR with an endogenous internal standard, GAPDH. The results showed that 1) in male rats fed ethanol chronically, there were no increases in c-myc mRNA; 2) increases, however, occurred in c-myc mRNA in muscle from female rats fed ethanol chronically; 3) raising endogenous acetaldehyde with cyanamide increased c-myc mRNA in acute studies; 4) starvation per se increased c-myc mRNA levels and at 1 day potentiated the acute effects of ethanol, indicative of a sensitization response; 5) the only effect seen with p53 mRNA levels was a decrease in muscle of rats starved for 1 day compared with fed rats, and there was no statistically significant effect on Bcl-2 mRNA in any of the experimental conditions. The increases in c-myc may well represent a preapoptotic effect, or even a nonspecific cellular stress response to alcohol and/or acetaldehyde. These data are important in our understanding of a common muscle pathology induced by alcohol.

scholarly journals Sex differences in sympathetic vasoconstrictor responsiveness and sympatholysis

2017 ◽  
Vol 123 (1) ◽  
pp. 128-135 ◽  
Author(s):  
Timothy P. Just ◽  
Darren S. DeLorey
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Sex Differences ◽  
Muscle Contraction ◽  
Vascular Resistance ◽  
Triceps Surae ◽  
Female Rats ◽  
Male Rats ◽  
Sympathetic Chain ◽  
Sympathetic Vasoconstriction

Sex differences in the neurovascular control of blood pressure and vascular resistance have been reported. However, the mechanisms underlying the modulatory influence of sex have not been fully elucidated. Nitric oxide (NO) has been shown to inhibit sympathetic vasoconstriction in resting and contracting skeletal muscle, and estrogen modulates NO synthase (NOS) expression and NO bioavailability. Therefore NO-mediated inhibition of sympathetic vasoconstriction may be enhanced in females. Thus the purpose of the present study was to investigate the hypothesis that sympathetic vasoconstrictor responsiveness would be blunted and NO-mediated inhibition of sympathetic vasoconstriction would be enhanced in females compared with males. Male (M; n = 8) and female (F; n = 10) Sprague-Dawley rats were anesthetized and surgically instrumented for measurement of arterial blood pressure and femoral artery blood flow and stimulation of the lumbar sympathetic chain. The percentage change of femoral vascular conductance in response to sympathetic chain stimulation delivered at 2 and 5 Hz was determined at rest and during triceps surae muscle contraction before (control) and after NOS blockade [ Nω-nitro-l-arginine methyl ester (l-NAME), 10 mg/kg iv]. At rest, sympathetic vasoconstrictor responsiveness was augmented ( P < 0.05) in female compared with male rats at 2 Hz [F: −33 ± 8% (SD); M: −26 ± 6%] but was not different at 5 Hz (F: −55 ± 7%; M: −47 ± 7%). During muscle contraction, evoked vasoconstriction was similar ( P > 0.05) in females and males at 2 Hz (F: −12 ± 5%; M: −13 ± 5%) but was blunted ( P < 0.05) in females compared with males at 5 Hz (F: −24 ± 5%; M: −34 ± 8%). l-NAME increased ( P < 0.05) sympathetic vasoconstrictor responsiveness in both groups at rest and during contraction. Contraction-mediated inhibition of vasoconstriction (sympatholysis) was enhanced ( P < 0.05) in females compared with males; however, sympatholysis was not different ( P > 0.05) between males and females in the presence of NOS blockade, indicating that NO-mediated sympatholysis was augmented in female rats. These data suggest that sex modulates sympathetic vascular control in resting and contracting skeletal muscle and that a portion of the enhanced sympatholysis in female rats was NO dependent. NEW & NOTEWORTHY Sex differences in the neurovascular regulation of blood pressure and vascular resistance have been documented. However, our understanding of the underlying mechanisms that mediate these differences is incomplete. The present study demonstrates that female rats have an enhanced capacity to inhibit sympathetic vasoconstriction during exercise (sympatholysis) and that NO mediates a portion of the enhanced sympatholysis.

scholarly journals Male-specific suppression of hepatic microsomal UDP-glucuronosyl transferase activities toward sex hormones in the adult male rat administered bisphenol A

2002 ◽  
Vol 368 (3) ◽  
pp. 783-788 ◽  
Author(s):  
Noriaki SHIBATA ◽  
Junya MATSUMOTO ◽  
Ken NAKADA ◽  
Akira YUASA ◽  
Hiroshi YOKOTA
Keyword(s):  
Bisphenol A ◽  
Mrna Expression ◽  
Sex Hormones ◽  
Adult Male ◽  
Endocrine Disruptor ◽  
Liver Microsomes ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Blotting Analysis

Various adverse effects of endocrine disruptors on the reproductive organs of male animals have been reported. We found that UDP-glucuronosyltransferase (UGT) activities towards bisphenol A, testosterone and oestradiol were significantly decreased in liver microsomes prepared from adult male Wistar rats administered with the endocrine disruptor bisphenol A (1mg/2 days for 2 or 4 weeks). However, suppression of the transferase activities was not observed in female rats, even after bisphenol A treatment for 4 weeks. Diethylstilbestrol, which is well known as an endocrine disruptor, had the same effects, but p-cumylphenol had no effect on UGT activities towards sex hormones. Co-administration of an anti-oestrogen, tamoxifen, inhibited the suppression of the transferase activities by bisphenol A. Western blotting analysis showed that the amount of UGT2B1, an isoform of UGT which glucuronidates bisphenol A, was decreased in the rat liver microsomes by the treatment. Northern blotting analysis also indicated that UGT2B1 mRNA in the liver was decreased by bisphenol A treatment. The suppression of UGT activities, UGT2B1 protein and UGT2B1 mRNA expression did not occur in female rats. The results indicate that bisphenol A treatment reduces the mRNA expression of UGT2B1 and other UGT isoforms that mediate the glucuronidation of sex hormones in adult male rats, and this suggests that the endocrine balance may be disrupted by suppression of glucuronidation.

EFFECT OF SEX AND AGE AT GONADECTOMY ON THE SEBACEOUS RESPONSE TO PROGESTERONE

1977 ◽  
Vol 73 (1) ◽  
pp. 67-70 ◽  
Author(s):  
SAM SHUSTER ◽  
WENDY M. HINKS ◽  
A. J. THODY
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Female Rats ◽  
Male Rats ◽  
Adult Males ◽  
Adult Rat ◽  
Sebum Production ◽  
Males And Females ◽  
Sebum Secretion

SUMMARY The effect of progesterone on the rate of sebum secretion was examined in intact and gonadectomized rats. In intact, adult, male rats, progesterone administered for 3 weeks decreased sebum secretion; after castration of adult males, progesterone increased sebum secretion and an even greater response occurred in males castrated at 21 days of age. In intact, adult, female rats progesterone slightly increased sebum production. As in the male, the response was affected by the time of gonadectomy, a greater response occurring after spaying at 21 days compared with 10 weeks of age. Thus, the response to progesterone in the adult rat differs in intact males and females and is affected by changes in the endocrine environment induced by gonadectomy, especially near the time of puberty.

scholarly journals RESPONSE OF MALE AND FEMALE WEANLING RATS TO DIETS OF DIFFERENT DIGESTIBLE ENERGY CONCENTRATIONS AND TO SUPPLEMENTATION WITH VITAMIN E, USING BARLEY OR WHEAT AS CEREAL SOURCES

1972 ◽  
Vol 52 (1) ◽  
pp. 81-86 ◽  
Author(s):  
J. F. O’GRADY ◽  
J. P. BOWLAND
Keyword(s):  
Vitamin E ◽  
Energy Levels ◽  
Maximum Growth ◽  
Female Rats ◽  
Male Rats ◽  
Male And Female ◽  
Digestible Energy ◽  
Male And Female Rats ◽  
Weanling Rats ◽  
Better Than

Sixty-four weanling rats were used in an experiment lasting 6 weeks to test the response of male and female rats to diets having 2.8, 3.0, 3.2, and 3.4 Mcal digestible energy (DE) per kg, where barley and wheat were used as the cereal sources and diets were supplemented with 22 IU vitamin E/kg or unsupplemented. The use of wheat or barley did not influence the performance of female rats but males utilized barley-based diets better than wheat diets and gained more in some weeks, though not overall. Male rats did not respond to vitamin E supplementation but females consumed more of the vitamin E-supplemented diets and grew 6% faster (P < 0.10). Except in the 1st week, females ate more of the lower energy than of the higher energy diets and so DE concentration did not influence rate of gain. Males were not able to adjust food intakes to compensate for dietary energy levels and needed a DE concentration of 3.2 Mcal/kg diet for maximum growth. The data indicate that there is a sex difference in growing rats insofar as DE concentration of the diet required for maximum gain is concerned.

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