Basic Research in Cardiology

, Volume 73, Issue 5, pp 422–432 | Cite as

The effect of beta adrenergic blockade on pulmonary hypertension, right ventricular hypertrophy and polycythaemia, induced in rats by intermittent high altitude hypoxia

  • B. Oštádal
  • J. Ressl
  • D. Urbanová
  • J. Widimský
  • J. Procházka
  • V. Pelouch
Original Contributions


Adult male rats were used to study the effect of a beta blocking agent on pulmonary hypertension and right ventricular hypertrophy induced by intermittent high altitude (IHA) hypoxia (8 hr daily, 5 days a week, stepwise up to the simulated altitude of 7000 m). Trimepranol was injected subcutaneously in a single dose of 10 mg/kg/b.w. one hour before each IHA exposure. Administration of the beta blocking drug caused significant changes of haematocrit values even in animals kept under normoxic conditions. The initial deep decrease was followed by a slow return to control values; prolongation of treatment led to a further significant decrease of the haematocrit curve. The polycythaemic response of IHA-exposed and Trimepranol-treated animals was, therefore, significantly less pronounced as compared with the hypoxic non-treated group. Administration of Trimepranol to IHA-exposed rats significantly decreased the values of right ventricular systolic and mean pressure, right ventricular hypertrophy as well as the degree of muscularization of pulmonary arteries.

It may be assumed that the protective effect of Trimepranol is due to a) changes in pulmonary vascularization, b) reduction of polycythaemia, and c) lower cardiac output, induced by the negative inotropic and chronotropic effect of this drug.


Pulmonary Hypertension Ventricular Hypertrophy Lower Cardiac Output Chronotropic Effect Adrenergic Blockade 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Pulmonaler Hochdruck, rechtsventrikuläre Hypertrophie und Polyzythämie bei Ratten als Folge intermittierender Hypoxie durch Höhenexposition und ihre Beeinflussung durch Beta-Rezeptoren-Blockade


Bei erwachsenen männlichen Ratten wurden die Auswirkungen einer Beta-Rezeptoren-Blockade auf die pulmonale Hypertension und die rechtsventrikuläre Hypertrophie untersucht, die durch Hypoxie unter intermittierender Höhenexposition ausgelöst wurden (8 Stunden täglich; 5 Tage pro Woche; stufenweise Steigerung bis zu einer simulierten Höhe bis zu 7000 m). Trimepranol wurde eine Stunde vor der Höhenexposition als Einzeldosis (10 mg/kg) subkutan injiziert. Die Verabfolgung des Beta-Rezeptoren-Blockers verursachte signifikante Änderungen der Hämatokritwerte selbst bei Tieren, die unter normoxischen Bedingungen gehalten wurden. Ein initialer erheblicher Abfall war gefolgt von langsamer Rückkehr zu den Kontrollwerten. Verlängerung der Behandlung führte zu weiterer signifikanter Abnahme des Hämatokrits. Die Polyzythämie nach Höhenexposition war daher bei mit Trimepranol behandelten Tieren eindeutig weniger ausgeprägt als bei der nicht behandelten “hypoxischen” Gruppe. Verabfolgung von Trimepranol reduzierte bei den Ratten mit Höhenexposition eindeutig den rechtsventrikulären systolischen Druck und Mitteldruck, die Hypertrophie des rechten Ventrikels und die Dicke der Muskelwand der Pulmonalarterie.

Man kann annehmen, daß der protektive Effect von Trimepranol a) auf Änderungen der pulmonalen Vaskularisation, b) auf eine Reduktion der Polyzythämie und c) auf ein geringeres Herz-Minuten-Volumen zu beziehen ist, letzteres induziert durch die negativ inotropen und chronotropen Effekte der Substanz.


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Copyright information

© Dr. Dietrich Steinkopff Verlag 1978

Authors and Affiliations

  • B. Oštádal
    • 1
  • J. Ressl
    • 1
  • D. Urbanová
    • 1
  • J. Widimský
    • 1
  • J. Procházka
    • 1
  • V. Pelouch
    • 1
  1. 1.Institute of PhysiologyCzechoslovak Academy of Sciences and Cardiovascular Research Centre of the Institute for Clinical and Experimental MedicinePrague(Czechoslovakia)

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