BARORECEPTOR REFLEX IN THE RAT AFTER CONVERTING ENZYME INHIBITION OR ANGIOTENSIN RECEPTOR BLOCKADE

1. One component of baroreflex responsiveness was quantitated in conscious rats using the heart rate response to a pressor injection of phenylephrine. 2. Endogenous angiotensin and its effectiveness were manipulated by sodium deprivation, converting enzyme inhibition and infusion of an angiotensin analogue. None of these manoeuvres changed the observed reflex responsiveness. 3. We conclude that endogenous angiotensin has no influence on the component of baroreceptor function that is described by the slope of the arterial pressure-heart rate relationship.     

Effect of new beta-adrenergic blocking agent, Atenolol (Tenormin), on pain frequency, trinitrin consumption, and exercise ability.

In 11 patients with severe angina pectoris a new beta-blocking drug, atenolol (Tenormin; I.C.I.66082), was found in a double-blind randomized trial to reduce significantly the frequency of anginal attacks (P less than 0-001) and the amount of trinitrin consumed (P less than 0-03) in comparison with practolol and placebo. There was no significant improvement in the patients' ability to exercise on the bicycle ergometer.     

“Masked” 21-hydroxylase deficiency of the adrenal presenting with gynecomastia and bilateral testicular masses

An infertile 27 year old man with precocious puberty is described. He presented in adulthood with unilateral and then bilateral gynecomastia, and subsequently testicular tumors developed. An early diagnosis of congenital adrenal hyperplasia would have avoided unnecessary surgery. Initial detailed metabolic evaluation led to the erroneous diagnosis of 11-hydroxylase deficiency because of the presence of an unusual steroid (21-desoxycortisol) in serum which was falsely reported as an increased 11-desoxycortisol (compound S). The observed low urinary pregnanetriol measurements would have supported this diagnosis. Subsequent specific measurements of 21-desoxycortisol established its presence in the serum and its major metabolite, tetrahydro-21-desoxycortisol, in the urine. The unique features in this case of 21-hydroxylase deficiency alert the physician to its unusual clinical presentation and the pitfalls that may be encountered when evaluating adrenal steroidogenesis.     

Application of the Beckman JE6-B Elutriator System® in the isolation of human monocyte subpopulations

Beckman Instruments recently developed an improved version of their JE-6 Elutriator Rotorr?. At 3000 rpm (867 x g), lymphocytes were eluted from the chamber at flow rates of 10 to 18 ml/min. Small monocytes (362 μ³) were collected at 18 ml/min over 400 ml while the larger monocytes (395 μ³) were retained in the chamber until the flow rate was increased to 28 ml/min. These parameters differ from those previously reported by us when we used Beckman's original commercial version of the JE-6 Elutriator Rotor. The new JE-6B rotor required an increase of centrifugal force from 625 to 867 x g generated by an increase in rpm from 2500 to 3000, as well as an increase in flow rates to collect both small (17 to 18 ml/min) and large (26 to 28 ml/min) monocytes. The monocytes collected using the new rotor with the revised protocol have the same physical and functional properties as those collected with the earlier version using our previously published protocol.