PubMed Health⌕ Search

Biomedical subjects

M NICKERSON

Publications and source records attributed to M NICKERSON.

At least 19 recordsLinked to original sources
PubMed1962

Clinical observations on an antihypertensive chlorothiazide analogue devoid of diuretic activity.

The antihypertensive effect of the diuretic benzothiadiazines has been attributed to salt depletion and the resultant reduction in plasma volume. The study described in this report was concerned with the effects of diazoxide, a non-diuretic analogue which had been found in animal experiments to have a hypotensive effect.Intravenous diazoxide (3 mg./kg.) reduced blood pressure an average of 26/16 mm. Hg in seven hypertensive subjects. An associated rise in cardiac output (0.7 to 5.7 1./min.) and decrease in peripheral vascular resistance occurred. There was no postural hypotension, or change in external salt balance or in the concentration of serum sodium or potassium.Oral administration of the drug (0.2 to 0.5 g./day for eight to 50 weeks) lowered blood pressure more than 15/10 mm. Hg in 26 of 30 hypertensive subjects. Associated effects were: (1) weight gain in 26 of 30 subjects, (2) anorexia in 15 of 30, (3) lacrimation in six of 30, (4) aggravation of diabetes in two, and (5) transient cardiac arrhythmias in four. This study suggests that this benzothiadiazine acts directly on arterioles to reduce peripheral vascular resistance.

Animals↗
PubMed1961

Involvement of adrenergic factors in the effects of bacterial endotoxin.

The possible involvement of adrenergic mechanisms in the effects of Escherichia coli endotoxin was investigated in several preparations. Appropriate pretreatment of rabbits with E. coli endotoxin significantly increased pressor responses to epinephrine and norepinephrine as compared to untreated controls. Exposure of isolated rabbit aorta strips to E. coli endotoxin in a medium containing whole blood or cellular constituents of blood significantly increased the response to epinephrine. Endotoxin had no effect on responses to epinephrine in ritro when plain Krebs-Ringer solution was used. Pretreatment with reserpine or phenoxybenzamine (dibenzyline) protected rabbits and mice against the acute lethal effects of E. coli endotoxin. The time period intervening between reserpine or dibenzyline administration and challenge by endotoxin precluded a direct antiendotoxic action of these agents. In addition, incubation of dibenzyline with endotoxin in vitro, under conditions which would favor reaction, did not decrease the toxicity of the latter. These results indicate that peripheral adrenergic mechanisms are intimately involved in the effects of E. coli endotoxin and support the concept that deleterious effects of endotoxin in shock probably are due to exaggeration of existing vasoconstriction in an already compromised organism.

Adrenergic Agents↗