Preventive and therapeutic effects of nitrendipine on hypoxic right ventricular hypertrophy.
OBJECTIVE
To assess whether nitrendipine (Nit) can be used to prevent and treat the hypoxic right ventricular hypertrophy (RVH).


METHODS
Rats were exposed to a simulated altitude of 5000 m (barometric pressure = 54 kPa) for 30-60 d. Nit (10-20 mg.kg-1.d-1) was administered via gavage. The therapeutic efficacy was evaluated with right ventricular weight index (RVWI), right ventricular systolic pressure (RVSP), and myocardial ultrastructure.


RESULTS
Chronic intermittent hypoxia for 30 d (8 h.d-1) resulted in an increase of RVSP and RVWI as well as in the changes of RV myocardial ultrastructure. As the hypoxic time was prolonged to 60 d, RVWI and RVSP were not further augmented. Nit (20 mg.kg-1.d-1, i.g.), when administered from the beginning of hypoxia, reduced RVSP (8.1 +/- 1.1 vs 6.0 +/- 1.0 kPa, P < 0.05) and RVWI (1.014 +/- 0.012 vs 0.915 +/- 0.049 mg/g body weight, P < 0.05). After development of hypoxic RVH, Nit (20 mg.kg-1) also decreased RVSP (7.9 +/- 1.0 vs 6.2 +/- 0.8 kPa, P < 0.05) and RVWI (1.02 +/- 0.13 vs 0.88 +/- 0.12 g/kg body weight, P < 0.05). Myocardial blood flow was increased and myocardial ultrastructure became nearly normal in rats treated with Nit.


CONCLUSIONS
Nit prevented and lessened the hypoxic right ventricular hypertrophy.
Xie
Z Z
ZZ
Institute of High Altitude Medicine, Third Military Medical College, Chongqing, China.
Liu
F Y
FY
Wang
S J
SJ
Wan
Q
Q
Qiu
Y F
YF
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D005260:Female; D017380:Hypertrophy, Right Ventricular / Q000517:prevention & control*; D000860:Hypoxia / Q000150:complications*; D008297:Male; D009206:Myocardium / Q000648:ultrastructure; D009568:Nitrendipine / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar
D002121:Calcium Channel Blockers; D009568:Nitrendipine