Role of sex hormones in development of chronic mountain sickness in rats
| Autor: | Roger P. Smith, L.C. Ou, Truls Brinck-Johnsen, James C. Leiter, G. L. Sardella |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
Pulmonary Circulation medicine.medical_specialty Physiology Ovariectomy Radioimmunoassay Blood Pressure Cardiomegaly Polycythemia Altitude Sickness Hematocrit Muscle hypertrophy Rats Sprague-Dawley Physiology (medical) Internal medicine medicine Animals Testosterone Orchiectomy Gonadal Steroid Hormones Sex Characteristics Estradiol medicine.diagnostic_test business.industry Hemodynamics Hypoxia (medical) Effects of high altitude on humans medicine.disease Pulmonary hypertension Rats Endocrinology Chronic mountain sickness Chronic Disease Female medicine.symptom business Hormone |
| Zdroj: | Journal of Applied Physiology. 77:427-433 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1994.77.1.427 |
| Popis: | After chronic exposure to hypoxia, Hilltop Sprague-Dawley rats developed excessive polycythemia and severe pulmonary hypertension and right ventricular (RV) hypertrophy, signs consistent with human chronic mountain sickness; however, there were gender differences in the magnitude of the polycythemia and susceptibility to the fatal consequence of chronic mountain sickness. Orchiectomy and ovariectomy were performed to evaluate the role of sex hormones in the gender differences in these hypoxic responses. After 40 days of exposure to simulated high altitude (5,500 m; barometric pressure of 370 Torr and inspired Po2 of 73 Torr), both sham-gonadectomized male and female rats developed polycythemia and had increased RV peak systolic pressure and RV hypertrophy. The hematocrit was slightly but significantly higher in males than in females. Orchiectomy did not affect these hypoxic responses, although total ventricular weight was less in the castrated high-altitude rats. At high altitude, the mortality rates were 67% in the sham-operated male rats and 50% in the castrated animals. In contrast, ovariectomy aggravated the high-altitude-associated polycythemia and increased RV peak systolic pressure and RV weight compared with the sham-operated high-altitude female rats. Both sham-operated control and ovariectomized females suffered negligible mortality at high altitude. The present study demonstrated that 1) the male sex hormones play no role in the development of the excessive polycythemia, pulmonary hypertension, and RV hypertrophy during chronic hypoxic exposure or in the associated high mortality and 2) the female sex hormones suppressed both the polycythemic and cardiopulmonary responses in vivo during chronic hypoxic exposure. |
| Databáze: | OpenAIRE |
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