Premium
Temperature‐dependent modulation of myogenic tone of isolated gracilis and coronary arterioles
Author(s) -
Banga Peter,
Racz Anita,
Toth Erika,
Toth Janos,
Koller Akos
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1404
Temperature‐induced changes in vasomotor responses of vascular rings are well investigated, yet the results are controversial. This could be due to the effect of temperature on the development of spontaneus tone of vessels. We hypothesized that changes in temperature affect the myogenic tone of arterioles. In isolated (37 °C, 80mmHg) gracilis (Gra, passive dia.: 220.4±9.4 ìm, active: 165±6.4 μm and coronary (Cor, passive dia.: 226.6±9.3 ìm, active: 122.9±6.3 μm,) arterioles changes in diameter were measured during increases (37–42°C) and decreases (37–32°C) of temperature of the physiological salt solution. Decreasing temperature elicited increases in the diameter [Gra: 198.1±10.2 μm (60±3.1%) and Cor: 165.7±7.6 μm (41.3±2.1%), p<0.05], whereas increasing temperature reduced the diameter [Gra: 128.8±13.7 μm (−22.4±2.3%) and Cor: 87.8±9.6 μm (−28.5±3.1%), p<0.05] of arterioles. Diameters changed in a linear manner as a function of temperature, but the slope of the linear regression curve was significantly greater in gracilis, as compared to coronary arterioles(−11.8±0.4 in Gra and −7.5±0.5 in Cor). These findings suggest that changes in temperature activate intrinsic mechanisms in the arteriolar wall, which in turn modulate resistance, and that skeletal muscle arterioles are more sensitive to temperature changes than coronary arterioles. Elucidation of the cellular pathways responsible for temperature‐sensitive vasomotor activity could contribute to a better understanding of temperature‐induced modulation of the microcirculation. (Grants: Hungarian Nat. Sci. Res. Funds, OTKA T‐48376 and NIH USA HL‐46813, AHA NE Aff. 0555897T).