The assay of hypertensin from the arterial blood of normotensive and hypertensive human beings

Hypertensin has been assayed in the blood of patients with normal blood pressure and in those with essential hypertension in both the benign and malignant phases. 250 ml. samples of arterial blood were obtained, chemically purified, and concentrated to a volume of 1 ml. These extracts were then assayed in anesthetized rats. The concentrations of hypertensin in the blood of patients with the malignant phase of essential hypertension were found to be greatly increased. The concentrations of hypertensin found in patients with benign hypertension had a moderate degree of overlapping with those found in the normotensive group, but the mean concentration of hypertensin in the former group was twice that of the controls. Although these results are statistically significant, the amounts of hypertensin recovered in the benign group are so small that no conclusions can be drawn as to its effectiveness in producing vasoconstriction in these patients.

EFFECTS OF CHRONIC EXCESS SALT INGESTION. ROLE OF GENETIC FACTORS IN BOTH DOCA-SALT AND RENAL HYPERTENSION

By selective inbreeding, two strains of rats were developed previously that differed markedly in their susceptibility to the development of experimental hypertension from excess salt ingestion (1, 2). The present report indicates that with animals derived from the same strains, similar differences in response were obtained in rats subjected to either combined desoxycorticosterone-NaCl (DOCA-salt) treatment or unilateral renal artery compression without extra dietary salt. Thus differences in genetic substrate appear to influence the development of experimental hypertension produced by these three techniques and possibly this may hold true for all "varieties" of experimental hypertension. If true, it might allow the development of a unifying hypothesis that could be relevant not only to experimental hypertension but perhaps to human hypertension as well. The DOCA-salt regimen was more toxic to the animals than unilateral renal artery compression. Tentatively, this was ascribed to either, or both, the younger age or the higher NaCl intake of the animals in the former.

Treatment of oesophageal varices in portal hypertension by means of sclerosing injections

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The syndrome of patent ductus arteriosus with pulmonary hypertension

Eight cases of patent ductus arteriosus associated with marked pulmonary hypertension are presented with complete cardiac catheterization studies in six patients and autopsy studies in three cases. Four patients had clear evidence of a "reversed" shunt through the ductus, three presenting the clinical picture of cyanotic congenital heart disease. The authors discuss the nature of the increased resistance of the pulmonary vascular bed which is the basis of the circulatory changes in these cases.

Amlodipine in hypertension: a first-line agent with efficacy for improving blood pressure and patient outcomes

OBJECTIVES

Hypertension is well established as a major risk factor for cardiovascular disease. Although there is undeniable evidence to support the beneficial effects of antihypertensive therapy on morbidity and mortality, adequate blood pressure management still remains suboptimal. Research into the treatment of hypertension has produced a multitude of drug classes with different efficacy profiles. These agents include β-blockers, diuretics, ACE inhibitors, angiotensin receptor blockers and calcium channel blockers. One of the oldest groups of antihypertensives, the calcium channel blockers are a heterogeneous group of medications.

METHODS

This review paper will focus on amlodipine, a dihydropyridine calcium channel blockers, which has been widely used for 2 decades.

RESULTS

Amlodipine has good efficacy and safety, in addition to strong evidence from large randomised controlled trials for cardiovascular event reduction.

CONCLUSIONS

Amlodipine should be considered a first-line antihypertensive agent.

ERYTHERMALGIA. REVIEW OF 51 CASES

The syndrome of erythermalgia is characterized by a burning distress of the extremities that is accompanied by redness and increased temperature of the skin. These symptoms are initiated or exacerbated by an increase in environmental temperature and diminished by measures that cool the skin. Of 51 patients with this clinical syndrome seen at the Mayo Clinic during the years 1951 to 1960 inclusive, 30 were considered as having primary erythermalgia because of the absence of demonstrable associated conditions, and the rest were classified as having secondary erythermalgia because the condition was associated with various diseases. Particularly significant was the relation of erythermalgia to the myeloproliferative disorders as evidenced in 10 cases. In some of these cases, erythermalgia preceded other manifestations of the myeloproliferative disorder by as long as 12 years. The primary type was found to occur in younger individuals and to be more often bilateral, to produce pain of greater intensity, and to involve larger areas of the affected extremities. The pathologic physiology of this syndrome remains unknown.

The purification and partial characterization of several forms of hog renin substrate

Hog renin substrate has been separated into three major (A, B, and C) and two minor forms (D and E) by DEAE cellulose chromatography. Two of the major forms (B and C) have been further fractionated into two additional types (1 and 2) by countercurrent distribution. The purification of substrates A, C₁, and C₂ has been completed. Analysis shows that all three are glycoproteins with molecular weights of about 57,000, and have similar amino acid compositions. Differences exist in the sialic acid, glucosamine, and neutral hexose content, which may account for different physical properties. All the forms of the substrates are attacked by renin at similar rates, and appear to yield the same angiotensin I.