EFFECTS OF SHORT-TERM AND LONG-TERM ANDROGEN TREATMENT ON THE DIAPHRAGM IN MALE AND FEMALE RATS

Citation
Dj. Prezant et al., EFFECTS OF SHORT-TERM AND LONG-TERM ANDROGEN TREATMENT ON THE DIAPHRAGM IN MALE AND FEMALE RATS, Journal of applied physiology, 75(3), 1993, pp. 1140-1149
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physiology
ISSN journal
8750-7587
Volume
75
Issue
3
Year of publication
1993
Pages
1140 - 1149
Database
ISI
SICI code
8750-7587(1993)75:3<1140:EOSALA>2.0.ZU;2-F
Abstract
The effects of short-term (2.5 wk) and long-term (10 wk) testosterone propionate (2.5 mg/day; 5 days/wk) treatment on diaphragm contractilit y, fatigue resistance, and fiber type proportions were studied in male and female rats. Contractility and fatigue resistance indexes were me asured in an in vitro diaphragm costal strip preparation by direct sti mulation at 37-degrees-C. The fatigue paradigm consisted of 30 trains/ min at 5 Hz (50% duty cycle) for 10 min. Fatigue resistance indexes we re calculated as postfatigue divided by baseline forces. In females bu t not males, testosterone treatment produced significant increases in body weight, costal diaphragm weight, and contractility and significan t decreases in fatigue resistance indexes. The interaction between tes tosterone treatment and the duration of treatment was significant, wit h the increase in contractility (females) being significant after shor t-term but not long-term treatment. No significant difference in fiber type proportions or areas was observed, regardless of treatment durat ion or the preexperimental, basal circulating level of androgen.