Effect of temperature on reactivity of saphenous, mesenteric, and femoral vehs of the dog

VANHOUTTE, PAUL M., AND ROBERT R. LORENZ. E$ect of temperature on reactivity of saphenous, mesenteric, and femoral veins of the dog. Am. J. Physiol. 218(6) : 1746-l 750. 1970.-The contraction of cutaneous veins of the dog caused by sympathetic nerve stimulation or by vasoactive drugs has been found previously to be potentiated by cooling and depressed by warming. To determine if this effect was specific for cutaneous veins, the thermosensitivity of helical strips of saphenous and femoral veins and of longitudinal strips of mesenteric veins of the dog was investigated. Strips from the three types of veins relaxed slightly during cooling (to 29 C) and contracted during warming (to 43 C). In addition, warming augmented the spontaneous activity exhibited by the mesenteric vein strips, whereas cooling had the opposite effect. Electric stimulation caused saphenous and mesenteric vein strips to contract, and these contractions were augmented by cooling and attenuated by warming. The femoral vein strips reacted to electric stimulation, norepinephrine, and 5-hydroxytryptamine; these reactions were attenuated by cooling and enhanced by warming. The data suggest that the potentiating effect of cold on adrenergic reactions is not specific for cutaneous veins but is not a general characteristic of venous smooth muscle.