+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Maturation affects the maximal pulmonary response to methacholine in rabbits



Maturation affects the maximal pulmonary response to methacholine in rabbits



Pediatric Pulmonology 16(1): 48-53



Maximal bronchoconstriction in normal adults produces only small reductions in pulmonary function; however, in normal infants severe airway obstruction limits testing to low agonist concentrations. In this study, maximal pulmonary response to methacholine was evaluated in 5 immature (1 month old) and 5 mature (6 months old) rabbits. Animals were anesthetized, paralyzed, and mechanically ventilated via a tracheostomy tube. Changes in pulmonary function were assessed from maximal deflation flow volume curves following inhalation of doubling concentrations of methacholine between 0.6 and 320 mg/mL. Following 320 mg/mL methacholine, the immature rabbits had a greater percent decline in forced vital capacity (FVC) than the mature animals (55 +/- 15% vs. 36 +/- 10%; P < 0.05). At 50% FVC, isovolume flows were measurable in the 5 mature rabbits, and 4 of 5 had plateaus in their dose-response curves. At the higher methacholine doses, only 1 of 5 immature animals had measurable isovolume flows because of the decrease in FVC. There was no significant difference between immature and mature animals in the methacholine dose required to decrease baseline flows by 50%. We conclude that in rabbits maturation affects maximal pulmonary response but not the sensitivity to methacholine.

(PDF emailed within 0-6 h: $19.90)

Accession: 046631653

Download citation: RISBibTeXText

PMID: 8414741

DOI: 10.1002/ppul.1950160110


Related references

Comparison of maximal pulmonary response to inhaled methacholine mch in mature and immature rabbits. Pediatric Research 29(4 PART 2): 378A, 1991

Increased maximal pulmonary response to methacholine and airway smooth muscle in immature compared with mature rabbits. American Journal of Respiratory and Critical Care Medicine 151(3 Pt 1): 836-840, 1995

Low-frequency pulmonary impedance in rabbits and its response to inhaled methacholine. Journal of Applied Physiology 73(1): 290-295, 1992

Effect of peep on the response of pulmonary resistance to methacholine Comparison of mature and immature rabbits. European Respiratory Journal 8(SUPPL 19): 208S, 1995

Interaction between lung tissues and airways during maximal methacholine induced constriction in rabbits. American Review of Respiratory Disease 139(4 PART 2): A134, 1989

Effect of allergen inhalation on the maximal response plateau of the dose-response curve to methacholine. American Review of Respiratory Disease 146(3): 565-569, 1992

Role of m2 muscarinic receptor in the airway response to methacholine of mice selected for minimal or maximal acute inflammatory response. Biomed Research International 2013: 805627-805627, 2013

Differences in sensitivity, maximal response and position of the concentration-response curve to methacholine between asthmatics, patients with allergic rhinitis and healthy subjects. Respiratory Medicine. 92(1): 88-94,., 1998

Dose response of trh on pulmonary maturation on corticosteroid treated preterm rabbits. American Journal of Obstetrics & Gynecology 163(2): 669-676, 1990

Sensitivity and maximal response to methacholine in perennial and seasonal allergic rhinitis. Clinical & Experimental Allergy 26(1): 61-67, 1996

Effect of challenge method on sensitivity, reactivity, and maximal response to methacholine. Annals of Allergy, Asthma & Immunology 97(2): 175-181, 2006

Does response of thyrotropin releasing hormone trh on pulmonary maturation in corticosteroid treated preterm rabbits. Clinical Research 38(1): 199A, 1990

Dose response of thyrotropin-releasing hormone on pulmonary maturation in corticosteroid-treated preterm rabbits. American Journal of Obstetrics and Gynecology 163(2): 669-676, 1990

Avoiding deep inspirations increases the maximal response to methacholine without altering sensitivity in non-asthmatics. Respiratory Physiology & Neurobiology 173(2): 157-163, 2010