Skip to main content

Spasmolytic effect of magnesium sulfate on serotonin-induced pulmonary hypertension and bronchoconstriction in dogs

Buy Article:

$43.00 plus tax (Refund Policy)


Magnesium (Mg2+) has relaxant effects on histamine-induced bronchoconstriction. In addition, Mg2+ has been reported to reduce vascular smooth muscle tone and be clinically useful for treatment of persistent pulmonary hypertension of the newborn. In this study, we evaluated the relaxant effect of Mg2+ on serotonin (5HT)-induced bronchoconstriction and pulmonary hypertension. Methods:

Seven mongrel dogs were anesthetized with pentobarbital (30 mg · kg−1+2 mg · kg−1 · h−1) and paralyzed by pancuronium (0.2 mg · kg−1 · h−1). Bronchoconstriction and pulmonary hypertension were elicited with 5HT (10 μg · kg−1+1 mg · kg−1 · h−1). Airway caliber was evaluated by changes in bronchial cross-sectional area (BCA) of the 3rd bronchial bifurcation measured by a fiberoptic bronchoscope method as previously reported. Pulmonary hypertension was assessed by changes in pulmonary vascular resistance (PVR). The BCA and PVR were expressed as per cent of the basal level. Thirty minutes after start of 5HT infusion, magnesium sulfate (MgSO4): 0 (saline), 1, 10, 100 and 1000 μmol · kg−1 was given iv. Arterial blood was also collected to measure plasma level of Mg2+ and catecholamines. Results:

5HT increased %PVR to 163±25% and decreased % BCA by 39.2±4.5%. Plasma level of Mg2+ following MgSO4 1000 μmol · kg−1 iv exceeded its toxic level. The ED50s of MgSO4 (dose producing 50% relaxation of maximal constriction) was 47.8 μmol · kg−1 and 1.09 mmol · kg−1 for pulmonary hypertension and bronchoconstriction, respectively. The ratio of %PVR to %SVR was about 1.0 after MgSO4 0–100 μmol · kg−1 iv, although the ratio significantly increased after 1000 μmol · kg−1 iv. Conclusion:

In dogs, 5HT-induced pulmonary hypertension but not bronchoconstriction was significantly reduced by an iv bolus of MgSO4, resulting in a plasma concentration within the assumed therapeutic level.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Magnesium sulfate; bronchoconstriction; pulmonary hypertension; serotonin

Document Type: Research Article

Publication date: 01 April 2001

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more