Bone mineral density is reduced by telmisartan in male spontaneously hypertensive rats.
BACKGROUND
Telmisartan, an angiotensin AT1 receptor blocker, and treadmill running were compared for their effects on bone mineral density (BMD) and biomechanical properties of male spontaneously hypertensive rats (SHR). It was hypothesized that running (18m/min/60min/d) and telmisartan (5mg/kg/d) would have a positive effect on bone parameters.


METHODS
Three-month-old male SHRs were divided into three groups: sedentary (S), telmisartan (T), and exercise (E). At the end of an 8-week protocol, femur and lumbar vertebrae were analyzed by dual-energy X-ray absorptiometry (DXA) for bone mineral density and by the three-point bending test for biomechanical properties. Blood pressure in all groups was measured by a tail-cuff manometer.


RESULTS
Telmisartan and treadmill running reduced blood pressure when compared to the sedentary group; however, telmisartan did not improve bone characteristics. Instead, it reduced BMD of femur total and lumbar vertebrae and worsened bone biomechanic properties. Treadmill running maintained bone characteristics and hence was effective in maintaining bone health.


CONCLUSIONS
Results showed that telmisartan negatively affected bones suggesting that caution should be taken in possible therapeutic applications for protecting bone health in hypertensive conditions. More studies are necessary to clarify the mechanisms through which telmisartan favors bone loss in this model.
Department of Health Integrated Education, Federal University of Espirito Santo,Vitória, Brazil. Electronic address: mbirocale@hotmail.com.
Antonio Marcos
AM
Birocale
Biological and Health Sciences, Federal Institute of Espirito Santo, Vitória, Brazil.
Ana Raquel Santos
AR
Medeiros
Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil.
Leandro Dias Gonçalves
LD
Ruffoni
Department of Medical Clinic, Medicine College, University of São Paulo, São Paulo, Brazil.
Liliam
L
Takayama
Laboratory of Applied Nuclear Physics, University of Sorocaba, Sorocaba, Brazil.
José Martins
JM
de Oliveira
Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil.
Keico Okino
KO
Nonaka
Department of Medical Clinic, Medicine College, University of São Paulo, São Paulo, Brazil.
Rosa Maria Rodrigues
RM
Pereira
Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Brazil.
Nazaré Souza
NS
Bissoli
D047228:Angiotensin II Type 1 Receptor Blockers / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D001562:Benzimidazoles / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D001565:Benzoates / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D005080:Exercise Test / Q000379:methods*; D006973:Hypertension / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000628:therapy*; D008297:Male; D010805:Physical Conditioning, Animal / Q000379:methods* / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D000077333:Telmisartan
D047228:Angiotensin II Type 1 Receptor Blockers; D001562:Benzimidazoles; D001565:Benzoates; D000077333:Telmisartan
Bone loss; Exercise; Hypertension; Telmisartan