Relationship between exercise-induced muscle damage and enzyme release in rats

1991 ◽  
Vol 71 (3) ◽  
pp. 999-1004 ◽  
Author(s):  
J. H. Van der Meulen ◽  
H. Kuipers ◽  
J. Drukker

The relationship between the amount of exercise-induced muscle damage and the release of creatine kinase (CK), aspartate aminotransferase (AST), and lactate dehydrogenase (LD) was studied. Gender differences in enzyme release and histological damage were also studied. Serial pre- and postexercise blood samples were drawn from untrained male and female catheterized Wistar rats that ran 1.5 or 2.5 h on a treadmill (incline 10 degrees). Three days postexercise, muscle damage was quantified morphometrically in five different hindlimb and forearm muscles. The 1.5 and 2.5 h of exercise elicited histological damage only in the soleus muscle. Significant plasma CK, AST, and LD elevations were found immediately postexercise both in male and female rats. However, the enzyme release was significantly greater in males than in females. Part of this could be explained by differences in clearance rates between males and females. No gender difference in amount of histological damage was found. The actual volume of histological muscle damage was significantly less than the calculated muscle damage based on enzyme release. An increase in the exercise duration from 1.5 to 2.5 h resulted in a disproportional increase in both histological muscle damage and muscle enzyme release. From the present study it is concluded that muscle enzyme release is not clearly reflected in histological muscle damage.

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Gemma Sanguesa ◽  
Aline Meza ◽  
Anna Alcarraz ◽  
Cira Rubies ◽  
Lluis Mont ◽  
...  

Introduction: There is emerging evidence in men that sustained high-intensity training promotes an adverse cardiovascular remodeling, thereby increasing the risk of atrial fibrillation, ventricular arrhythmias and coronary calcification. Whether men and women are similarly affected by high intensity exercise-induced harm is unclear. Our aim was to study sex differences in a long-term endurance training rat model. Methods: Male and female Wistar rats were subjected to high intensity training for 16 weeks (INT, 60min 60cm/s, male n=20, female n=15). Sedentary rats (SED, male n=20, female n=18) were used as controls. At the end of the training period, rats had an electrocardiogram and echocardiography performed. Vascular fibrosis was assessed in descending aorta, left carotid, and intramyocardial arteries (IMA), right and left atria, and left ventricle (LV) histological samples. mRNA levels of cardiac hypertrophy, fibrosis, oxidative stress and inflammation genes were assessed in LV samples by Real-Time PCR. Results: INT male rats presented lower heart rate (382±9, 340±10, SED vs INT, p<0.01) and a longer QRS duration (18.8±0.6, 22.4±1.1, SED vs INT, p<0.01), while these were not modified in the INT female group. Echocardiography showed eccentric LV hypertrophy in both trained male and female rats. High intensity exercise induced fibrosis in the descending aorta and carotid in both males and females, but IMA were only affected in trained male rats. In the heart, exercise-induced atrial fibrosis similarly occurred in both trained male and female rats. No training-induced fibrosis was evident in the LV of both INT male and female rats. Regarding LV mRNA analysis, INT males showed a reduction of desmin, TTN and N2BA/N2B ratio, whereas INT females exhibited higher desmin mRNA levels and lower αMHC/βMHC ratio. Intense exercise did not increase LV mRNA levels of fibrosis, oxidative stress and inflammation markers neither in males nor in females. In comparison to males, females had lower LV myocardial fibrosis as well as lower fibrosis markers. Conclusions: Male and female rats exhibit qualitatively different cardiovascular remodeling after extreme exercise. Nevertheless, both sexes might develop exercise-induced adverse vascular and cardiac effects.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A974-A974
Author(s):  
Marco Antonio Parra-Montes de Oca ◽  
Karen Lissette Garduño-Morales ◽  
Patricia Joseph-Bravo

Abstract Voluntary exercise activates HPT axis1, that contributes to energy mobilization and energy expenditure. Chronic stress in adulthood inhibits HPT response to voluntary wheel running in a sex dependent manner, inhibiting lipolysis of WAT2. We evaluated the effect of chronic stress during adolescence on HPT axis response to voluntary exercise in adulthood3, with emphasis on metabolic response in skeletal muscle and WAT. Wistar male and female rats (N=36 per sex) were divided in an undisturbed group (Control, C; n=18) and one chronic variable stress during adolescence group (CVS; n=18) (males: PND 30-70; females: PND 30-60). As adults (males: PND 84; females: PND: 74) rats were divided in: 1) exercise group: rats placed individually in a cage with a running wheel per 14 nights, 2) sedentary group with ad libitum feeding, 3) sedentary pair-fed group offered the same amount of food consumed by the exercised group, and kept in individual cages during 14 nights (6 rats/group). WAT weight was determined at sacrifice, hormones quantified by RIA and ELISA, gene expression by RT-PCR. Exercise-induced loss of fat mass was not detected in CVS rats. Exercise decreased corticosterone levels in C males and females of both treatments, supporting sex difference on HPA axis reprogramming by CVS. HPT axis response to voluntary exercise is attenuated by CVS also in a sex dimorphic manner: CVS decreased Trh expression in hypothalamic paraventricular nucleus and no changes in thyroid hormones concentration in males, whereas in females, slightly increased TSH, T4 and T3 levels. Sex also influenced the response of skeletal muscle and WAT to CVS. Dio2 and Pgc1a slightly increased expression in skeletal muscle of males, not of females. Adrb3 expression in WAT increased in females, but not in males; exercise-induced stimulation of Hsl expression was not observed in either sex after CVS. These results suggest that CVS imposed during rat adolescence inhibits the responses to voluntary exercise of HPT axis activity of thyroid hormone-targets in WAT and skeletal muscle in sex dependent manner. These changes could lead to reduced mobilization and the utilization of energy fuels coincident with the fatigue observed after exercise in patients with subclinical or clinical hypothyroidism. (Funded: CONACYT 284883, DGAPA IN213419)1Uribe, Endocrinology 155:2020-2030, 2014.2Parra, Front Endocrinol 10(418):1-13, 2019.3Parra, J Endocr Soc 4(Abstract Supp) Abstract SAT-451, 2020.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fawzi Babiker ◽  
Aishah Al-Jarallah ◽  
Mariam Al-Awadi

Background. Aging, left ventricular hypertrophy (LVH), diabetes mellitus, and pregnancy are well-recognized risk factors that increase the prevalence of cardio-ischemic events and are linked to poor clinical recovery following acute myocardial infarction. The coexistence of these risk factors with ischemic heart disease (IHD) deteriorates disease prognosis and could potentially lead to fatal arrhythmias and heart failure. The objective of this study was to investigate the vulnerability of hearts with aging, LVH, diabetes, and pregnancy to ischemic insult and their response to pacing postconditioning- (PPC-) induced heart protection. Methods. Hearts isolated from aged, spontaneously hypertensive and diabetic male and female rats and hearts from pregnant female rats (n=8 per group) were subjected to coronary occlusion followed by reperfusion using a modified Langendorff system. Hemodynamics data were computed digitally, and cardiac damage was accessed by measurements of infarct size and cardiac enzyme release. Results. There were no significant differences in the vulnerability of all hearts to ischemic insult compared to their respective controls. PPC improved cardiac hemodynamics and reduced infarct size and cardiac enzyme release in hearts isolated from aged and spontaneously hypertensive female rats and female rats with hypertrophied hearts subjected to PPC (P<0.001). Aged or hypertrophied male hearts were not protected by PPC maneuver. Moreover, the protective effects of PPC were lost in diabetic male and female hearts although retained in hearts from pregnant rats. Conclusions. We demonstrate that aging, LVH, diabetes mellitus, and pregnancy do not affect cardiac vulnerability to ischemic insult. Moreover, PPC mediates cardioprotection in a gender-specific manner in aged and spontaneously hypertensive rats. Diabetes mellitus provokes the protective effects of PPC on both genders equally. Finally, we demonstrate that PPC is a new cardioprotective maneuver in hearts from pregnant female rats.


2001 ◽  
Vol 280 (6) ◽  
pp. C1570-C1575 ◽  
Author(s):  
Emil Wolsk Petersen ◽  
Kenneth Ostrowski ◽  
Tobias Ibfelt ◽  
Myriam Richelle ◽  
Elizabeth Offord ◽  
...  

The present double-blinded, placebo-controlled study investigated whether antioxidant vitamin supplementation was able to modulate the cytokine and lymphocyte responses after strenuous eccentric exercise. Furthermore, muscle enzyme release was examined to see whether antioxidant treatment could reduce muscle damage. Twenty male recreational runners randomly received either antioxidants (500 mg of vitamin C and 400 mg of vitamin E) or placebo for 14 days before and 7 days after a 5% downhill 90-min treadmill run at 75% V˙o 2 max. Although the supplemented group differed significantly with regard to plasma vitamin concentration before and after exercise when compared with the placebo group, the two groups showed identical exercise-induced changes in cytokine, muscle enzyme, and lymphocyte subpopulations. The plasma level of interleukin (IL)-6 and IL-1 receptor antagonist increased 20- and 3-fold after exercise. The plasma level of creatine kinase was increased sixfold the day after exercise. The concentrations of CD4+ memory T cells, CD8+ memory and naı̈ve T cells, and natural killer cells increased at the end of exercise. The total lymphocyte concentration was below prevalues in the postexercise period. In conclusion, the present study does not support the idea that exercise-induced inflammatory responses are induced by free oxygen radicals.


1989 ◽  
Vol 67 (2) ◽  
pp. 804-810 ◽  
Author(s):  
P. W. Sylvester ◽  
S. Forczek ◽  
M. M. Ip ◽  
C. Ip

Adult male and female Sprague-Dawley rats were trained on a horizontal treadmill for 0, 1, 3, 5, or 7 days/wk for 10 wk. Speed and duration were progressively increased over 5 wk to a maximum of 20 m/min for 1 h. Between weeks 9 and 10 of training, animals were placed on the nonmoving treadmill, and blood (500 microliters) was sampled via chronic venous cannulas 30 min before, 0, 10, 20, 30, 45, and 60 min during exercise, and 15, 30, 60, 90, and 120 min after exercise. In another study, resting animals in the various groups were injected with thyrotropin-releasing hormone (TRH; 2 micrograms/kg for males and 0.4 microgram/kg for females) to determine pituitary prolactin responsiveness. In males, exercise induced a significant increase in plasma prolactin levels, with the greatest increase observed in the least trained and the smallest increase in the most highly trained animals. Female rats displayed the opposite trend with the greatest increase in prolactin secretion observed in the highest trained and the smallest increase observed in the least trained animals. TRH induced similar increases in plasma prolactin in all male groups, whereas TRH-induced prolactin release was greatest in the highest trained and smallest in the least trained females. The reduced prolactin response in highly trained males may reflect their acclimation to repetitive exercise stress, whereas the enhanced response in the highly trained female rats appears to result from increased pituitary sensitivity to prolactin-releasing factors.


1961 ◽  
Vol 38 (1) ◽  
pp. 50-58 ◽  
Author(s):  
N. E. Borglin ◽  
L. Bjersing

ABSTRACT Oestriol (oestra-1,3,5(10)-triene-3,16α,17β-triol) is a weakly oestrogenic substance which, however, in contrast to what was formerly believed, is of physiological significance. Its effect is localized largely to the uterine cervix and vagina. Clinical experience argues both for and against an effect on the pituitary gland. This investigation is concerned with the morphological changes in the pituitary gland and adrenal cortex of gonadectomized male and female rats after the injection of oestriol. It was found that oestriol has the same type of action on these glands as other oestrogens, but under the experimental conditions used, this effect proved much weaker than that produced by oestradiol (oestra-1,3,5(10)-triene-3,17β-diol).


1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.


1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.


1988 ◽  
Vol 117 (4_Suppl) ◽  
pp. S191-S192
Author(s):  
M. STOPPOK ◽  
H. SCHRIEFERS ◽  
E. R. LAX

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