Increased capillary supply in skeletal muscle of guinea pigs acclimated to cold
| Autor: | Andrew J. Lechner, A. H. Sillau, Natalio Banchero, Lynn Aquin, Minh Van Bui |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Pulmonary and Respiratory Medicine
Male medicine.medical_specialty Aging Time Factors Physiology ATPase Guinea Pigs Apparent oxygen utilisation Weanling Guinea pig Internal medicine medicine Animals Fiber biology Chemistry Myoglobin Muscles Body Weight Skeletal muscle Anatomy Oxygenation Adaptation Physiological Capillaries Cold Temperature Endocrinology medicine.anatomical_structure biology.protein medicine.symptom Weight gain |
| Zdroj: | Respiration physiology. 42(3) |
| ISSN: | 0034-5687 |
| Popis: | The ATPase technique was used to visualize blood capillaries and to study fiber composition in 10-micrometer transverse sections of guinea pig gastrocnemius and soleus muscles. A control group of newborn, weanling, juvenile and adult male guinea pigs (GP) (BW = 89-1274 g) was studied in a 20-24 degrees C environment (22 degrees C GP) while 2-3 week old animals were exposed continuously to 5 degrees C for 2-18 weeks before sacrifice (5 degrees C GP) (BW = 239-1074 g). Body weight gain was not affected by cold exposure; however, the gastrocnemius and soleus muscles of the 5 degrees C GP grew at a slower rate than did the muscles of the 22 degrees C GP. The equations relating fiber cross sectional area (FCSA) and muscle weight (MW) were not different between the 22 degrees C GP and 5 degrees C GP for the soleus and gastrocnemius. Therefore, in both muscles at the same BW, FCSA was smaller in the 5 degrees C GP than in the 22 degrees C GP. In both of the two muscles of each group, capillary density (CD) decreased hyperbolically with increasing FCSA, while the capillary to fiber ratio (C/F) and the average number of capillaries around each fiber (CAF) increased linearly with increasing FCSA. The regression lines for CD, C/F and CAF versus FCSA for both muscles were parallel between groups, but at any FDSA, the CD, C/F and CAF were greater in the 5 degrees C GP than in the 22 degrees C GP. Percent fiber composition of the gastrocnemii of the 22 degrees C GP and 5 degrees C GP were not different; however, at the same FCSA each fiber type had a greater capillary supply in the 5 degrees C GP. The increased capillarity in the gastrocnemius and soleus muscles of the 5 degrees C GP suggests an improved capacity for oxygenation, a response which would correlate well with the increased oxygen utilization during prolonged cold exposure. |
| Databáze: | OpenAIRE |
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