Gender-specific effects of dexamethasone treatment on rat diaphragm structure and function

• Published in: Journal of applied physiology (1985) Vol. 82; no. 1; pp. 125 - 133
• Main Authors: Prezant, D. J, Karwa, M. L, Richner, B, Maggiore, D, Gentry, E. I, Cahill, J
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.01.1997; American Physiological Society
• Subjects: Animals; Biological and medical sciences; Dexamethasone - pharmacology; Diaphragm - drug effects; Diaphragm - physiology; Drug toxicity and drugs side effects treatment; Female; Male; Medical sciences; Pharmacology. Drug treatments; Rats; Rats, Wistar; Sex Characteristics; Toxicity: respiratory system, ent, stomatology; Corticosteroid; Animal model; Dexamethasone; Rat; Steroid hormone; Toxicity; Antiinflammatory agent; Rodentia; Contractility; Sex; Respiratory system; Long term; Vertebrata; Chemotherapy; Mammalia; Treatment; Respiratory muscle; Animal; Diaphragm; Sexual dimorphism
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1997.82.1.125

D. J. Prezant 1 , 2 , M. L. Karwa 1 , B. Richner 1 , D. Maggiore 1 , E. I. Gentry 1 , and J. Cahill 1 1  Department of Medicine, Pulmonary Division, and 2  Department of Physiology and Biophysics, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York 10467 Received 5 June 1995; accepted in final form 6 September 1996. Prezant, D. J., M. L. Karwa, B. Richner, D. Maggiore, E. I. Gentry, and J. Cahill. Gender-specific effects of dexamethasone treatment on rat diaphragm structure and function. J. Appl. Physiol. 82(1): 125-133, 1997. The effects of long-term dexamethasone treatment on diaphragm muscle were studied in female and male rats. Compared with pair-fed control animals, dexamethasone treatment did not significantly affect estrous cycling or peak serum estradiol levels; however, testosterone levels were significantly increased in females and decreased in males. Dexamethasone significantly reduced body and costal diaphragm weights, but to a lesser extent in females than in males. Reductions in diaphragm weight were proportional to reductions in body weight. In females and males, dexamethasone treatment significantly decreased diaphragm fiber (types I and II) cross-sectional area and the relative expression of myosin heavy chain isoform 2B. With the exception of type I fiber atrophy, these changes occurred to a lesser extent in females. Dexamethasone did not significantly affect specific forces. Dexamethasone significantly increased twitch one-half relaxation time and fatigue resistance indexes in males but not in females. In conclusion, the effects of long-term dexamethasone treatment were gender specific, with significantly fewer effects in females, and changes in serum testosterone levels were associated with these findings. respiratory muscles; gender differences 0161-7567/97 $5.00 Copyright © 1997 the American Physiological Society