Effects of Voluntary Exercise on Bone Growth and Calcium Metabolism in Spontaneously Hypertensive Rats

Umemura, Yoshihisa; Ishiko, Toshihiro; Aoki, Kazuhiro; Gunji, Atsuko

doi:10.1055/s-2007-1021301

Cited by 6 publications

(4 citation statements)

References 14 publications

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“…Similarly, endurance running (Saville and White 1969;Shimegi et al 1990;Forwood and Parker 1991;Yeh et al 1993), wheel running (Leblance et al 1983Newhall et al 1991;Umemura et al 1992) and jump training (Umemura et al 1995) has been shown to increase bone mass in rats. In these animals, it has been found that bone remodelling imbalance spontaneously occurs with aging and after castration, because bone resorption then exceeds bone formation (Burr and Martin 1989).…”

Section: Introductionmentioning

confidence: 98%

Treadmill running starting 3 months after orchidectomy restores femoral bone mass in rats

Horcajada-Molteni

Davicco

Coxam

et al. 1999

European Journal of Applied Physiology

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The present study was designed to provide data on the effects on femoral bone of endurance training starting only 3 months after orchidectomy in rats. A total of 70 Wistar male rats were used at 8 weeks of age. On day 0 of the experiment, 10 rats were killed by cervical dislocation to be used as first controls. Among the 60 other animals, half was surgically castrated (CX) or sham operated (SH). On day 90, 10 CX and 10 SH were killed and used as intermediary controls (ICX and ISH). Among the other 20 CX and 20 SH, 10 within each group (CXE, SHE) were selected for treadmill running (60% maximal oxygen uptake, 1 h x day(-1), 5 days x week(-1) for 12 weeks). The 20 other rats were used as sedentary controls (CXR, SHR) and killed (as runners) on day 180. On day 90 femoral bone density (BMD) and mineral content (BMC) were lower in ICX than in ISH. On day 180 total femoral BMD was lower in CXR than in CXE. Simultaneously metaphyseal femoral BMD was lower in CXR than in CXE, SHR or SHE. Furthermore, at that time, no significant difference concerning BMD and BMC was observed between SHR and CXE. This would indicate that treadmill running starting only 3 months after orchidectomy is able to restore BMD and BMC to control values, mainly by inhibiting bone resorption (as shown by decreased urinary deoxypyridinoline excretion in CXE) without decreasing osteoblastic activity (evaluated by plasma osteocalcin concentration).

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Section: Introductionmentioning

confidence: 98%

Treadmill running starting 3 months after orchidectomy restores femoral bone mass in rats

Horcajada-Molteni

Davicco

Coxam

et al. 1999

European Journal of Applied Physiology

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“…Bone remodeling is controlled by both mechanical and hormonal factors (7,9). Moderate physical exercise such as voluntary and/or endurance run training (8,27,31,42), wheel running (19,20,35), swimming (32), and jump training (36) has been shown to increase bone mass in rats. However, intensive [80% of maximal O 2 consumption (V O 2 max ), 1 h/day, 5 days/wk for 11 wk] swimming (3) or treadmill running (2) leads to retarded longitudinal bone growth, architectural alteration, and osteoblastic impairment in the tibia of 3-wk-old male rats.…”

mentioning

confidence: 99%

Influence of treadmill running on femoral bone in young orchidectomized rats

Horcajada¹,

Coxam

Davicco

et al. 1997

Journal of Applied Physiology

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Forty 6-wk-old male Wistar rats weighing 308 +/- 24 g were divided into two groups. On day 0, the 20 animals in one group were surgically castrated and the other group was sham operated. Within each group, 10 rats were selected for treadmill running (60% maximal O2 consumption, 1 h/day, 6 days/wk for 15 wk). The 20 sedentary rats were used as controls. At the time the rats were killed (day 105), running had no significant effect on femoral mechanical properties either in castrated or in sham-operated rats. Femoral bone density was lower in orchidectomized than in sham-operated rats. Nevertheless, it was higher in exercised than in sedentary rats. Femoral Ca content paralleled changes in bone density. Treadmill running had no significant effect on plasma osteocalcin concentration but inhibited the increase in urinary deoxypyridinoline excretion observed in castrated rats. Image analysis (measured at the distal femoral diaphysis) revealed that these effects mainly resulted from decreased trabecular bone resorption in castrated exercised rats.

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“…In SHRs performing free running wheel exercise, trained SHRs had higher plasma PTH concentrations (Umemura et al. ). However, it is unlikely that high PTH directly reduces renal PTHR1 expression.…”

Section: Discussionmentioning

confidence: 99%

“…Again, a potential molecular mechanism has not been identified for either of the two mechanisms. In SHRs performing free running wheel exercise, trained SHRs had higher plasma PTH concentrations (Umemura et al 1992). However, it is unlikely that high PTH directly reduces renal PTHR1 expression.…”

Section: Discussionmentioning

confidence: 99%

Effect of free running wheel exercise on renal expression of parathyroid hormone receptor type 1 in spontaneously hypertensive rats

et al. 2018

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An active lifestyle is generally recommended for hypertensive patients to prevent subsequent end‐organ damage. However, experimental data on long‐term effects of exercise on hypertension are insufficient and underlying mechanisms are not well understood. This study was aimed to investigate the effect of exercise on renal expression of parathyroid hormone‐related protein (PTHrP) and parathyroid hormone receptor type 1 (PTHR1) in spontaneously hypertensive rats (SHR). Twenty‐four rats started free running wheel exercise at the age of 1.5 months (pre‐hypertensive state) and proceeded for 1.5, 3.0, 6.0, and 10.0 months. Thirty rats kept under standard housing conditions were used as sedentary controls. Kidney function was assessed by measuring plasma creatinine levels and urine albumin‐to‐creatinine ratios. Renal expression of PTHrP and PTHR1 was analyzed by qRT‐PCR and western blot. Renal expression of PTHR1 was markedly increased between the 6th and 10th months in sedentary rats and this increase was significantly lower in SHRs with high physical activity on mRNA (−30%) and protein level (−27%). At the same time, urine albumin‐to‐creatinine ratio increased (from 65 to 231 mg/g) but somehow lower in exercise performing SHRs (48–196 mg/g). Our data suggest that enhanced exercise, stimulated by allocation of a free running wheel, is associated with lower PTHR1 expression in SHRs and this may contribute to preserved kidney function.

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Effects of Voluntary Exercise on Bone Growth and Calcium Metabolism in Spontaneously Hypertensive Rats

Cited by 6 publications

References 14 publications

Treadmill running starting 3 months after orchidectomy restores femoral bone mass in rats

Treadmill running starting 3 months after orchidectomy restores femoral bone mass in rats

Influence of treadmill running on femoral bone in young orchidectomized rats

Effect of free running wheel exercise on renal expression of parathyroid hormone receptor type 1 in spontaneously hypertensive rats

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