Effects of calcitonin on limb blood vessels in human obstructive arterial disease.

ABSTRACT

To check the possibility of a vasoactive effect of calcitonin in man, the authors treated ten hospitalized patients (seven males and three females, mean age 66.3 +/- 3.24), suffering from obstructive arterial disease in the lower extremities, with 100 units M.R.C. i.m. daily, for a period of 15 days. Five patients presented Raynaud's phenomenon. Treatment (B) led to an improvement of subjective symptomatology and to the disappearance of Raynaud's phenomenon in comparison with symptoms before treatment (A) and after a placebo period of 15 days (C). With respect to instrumental parameters, calcitonin induced a) a slight increase of segmental plethysmography values (height/width ratio of curves) if compared with A (p less than 0.05) and more significantly if compared with C (p less than 0.01 and less than 0.0125, from right and left sides, respectively); b) a small change in venous-occlusion plethysmography values, if compared with A and C, both in basal conditions and after the "ischaemic test"; c) a significantly lesser reduction of digital photoelectric plethysmography values (height/width ratio of curves) after the "cold test" in comparison with A (p less than 0.01, both on the second and on the third fingers of the right hand), as well as with C (p less than 0.01 and p less than 0.025, on the second and on the third fingers, respectively). The present investigation points out the vasoactive influence of calcitonin in human obstructive disease. Results show the improvement in collateral limb circulation and, above all, in the amount of cutaneous flow. Little information is available on the mechanism of this effect, for which only hypotheses can at present be advanced.