Inflammation in healing. 1. Time-course and mediation of exudation in wound healing in the rat

The time-course of increased vascular permeability in excised wounds in the skin of the rat was measured by injecting Evan's blue i.v. at various times after wounding and extracting the dye which exuded into the injured tissues during various short intervals of time. A single peak of increased permeability occurred within the first hour after which exudation rapidly diminished to a low level which then persisted for at least 5 days after wounding.

In animals with circulating colloidal carbon only venules in the edge and floor of wounds exhibited increased permeability during the phase of maximum exudation, after which leakage occurred only from capillaries in the advancing edge of the healing granulation tissue.

In controlled experiments, using rats matched for weight, the exudation in the first 30 min. after wounding was partially suppressed by inhibitors of histamine and serotonin, but not by anti-inflammatory agents which inhibit the kinins and/or kallikrein.

It is concluded that, in the absence of exogenous irritation, the inflammatory component of the process of healing after cutaneous wounding is evanescent, slight in magnitude, and mediated by histamine and serotonin.

Effect of reserpine in Raynaud's phenomenon

The responses of the blood vessels of the hand to intra-arterial infusion of tyramine and to application of ice to the forehead were examined in patients with Raynaud's phenomenon and in normal subjects. The vasoconstrictor responses to tyramine and to ice were not significantly different in the patients and control subjects. Following intra-arterial administration of reserpine the vasoconstrictor response to tyramine was unaffected, while that in response to ice was significantly reduced to a comparable extent in both the patients and the control subjects. Catecholamine concentrations in brachial arterial and hand venous plasma were not significantly different in the patients and in the control subjects. Following oral administration of reserpine (1 mg/day) the vasoconstrictor responses to intra-arterial tyramine and to the application of ice were markedly reduced in patients with Raynaud's phenomenon. In response to this form of treatment eight of the nine patients followed for 1 to 3 years showed improvement characterized by decreased frequency and severity of vasospastic attacks and by healing of ulcerations. In two patients the improvement was temporary despite continued reserpine therapy.

The relation between cell proliferation and the vascular system in a transplanted mouse mammary tumour

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