5-Hydroxytryptamine can mediate endothelium-dependent relaxation of coronary arteries

5-Hydroxytryptamine caused contractions of isolated canine coronary artery rings. These contractions were larger in the absence of the endothelium, whereas those caused by phenylephrine, potassium chloride, and prostaglandin F2 alpha were not. When coronary arteries were contracted with prostaglandin F2 alpha, 5-hydroxytryptamine caused relaxation in some rings with endothelium but only further contraction in all rings without endothelium. The inhibitory action of 5-hydroxytryptamine mediated by the endothelium was unaffected by blockade of monoamine oxidase or cyclooxygenase. In rings with endothelium, aggregating platelets, which released 5-hydroxytryptamine and thromboxane A2, caused relaxation. The relaxations caused by 5-hydroxytryptamine and aggregating platelets were antagonized by methysergide but not by ketanserin. These observations suggest that the response to 5-hydroxytryptamine is the net result of a direct contractile action on coronary smooth muscle and an inhibitory action mediated by the endothelium. In some vessels the endothelium-dependent inhibitory responses to aggregating platelets may be mediated in part by released 5-hydroxytryptamine. The serotonergic receptors on endothelial cells may be of a different subtype than those mediating contractions of the smooth muscle cells.

Digital vasodilatation during mental stress in patients with Raynaud's disease

Fingertip blood flow was measured by venous occlusion plethysmography before and during a stressful mental task consisting of rapid serial arithmetic calculations in a 25 degrees C room. Significant rises in heart rate and blood pressure indicated that stress was actually induced in all individuals. During mental stress in normal subjects, blood flow decreased (46.4 +/- 6.2 to 22.4 +/- 4.9 ml X min-1 per 100 ml tissue; P less than 0.01) and vascular resistance increased (2.1 +/- 0.4 to 7.6 +/- 2.2 units; P less than 0.01). Patients with Raynaud's disease unexpectedly increased blood flow (15.4 +/- 4.2 to 21.6 +/- 5.7; P = 0.05) and decreased vascular resistance (9.7 +/- 2.3 to 7.1 +/- 1.4; P = 0.05). Ten additional normal subjects were studied in a cool room (20 degrees C). Their digits remained vasoconstricted during stress, as blood flow (7.4 +/- 2.9 to 5.1 +/- 1.3) and vascular resistance (31.5 +/- 11.1 to 34.4 +/- 8.2) varied insignificantly (P greater than 0.10). The digital vasodilatation which occurs during mental stress in patients with Raynaud's disease was not altered by pretreatment with oral indomethacin, with intra-arterial propranolol or atropine, or by digital nerve block. These findings suggest the existence of an active digital vasodilatory mechanism in patients with Raynaud's disease.

Topography of Chlamydomonas: fine structure and polypeptide components of the gametic flagellar membrane surface and the cell wall

Surface polypeptide components of the flagellar membrane of Chlamydomonas reinhardi Dang. gametes are identified by their accessibility to in-vivo vectoral labeling by glucose oxidase-coupled lactoperoxidase-dependent (125)I iodination. Vectoral labeling is accomplished without observable adverse effects on cell viability or gametic function. Flagella isolated from labeled wild-type cells carry about 3% of the total incorporated label, which is found by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be distributed among 16 identifiable polypeptide bands. The most prominent surface-labeled species migrates in the Mr (relative molecular weight) 350 k region of the gel; each of the remaining iodinated polypeptides, which range in Mr from 25 k to 500 k, carries only a small proportion of incorporated label. To determine which polypeptides are unique to the flagellum and which are contaminants from the cell wall, wild-type profiles were compared with those of mutant strains and of mechanically isolated cell walls. Identification of contaminants was also facilitated by two-dimensional peptide mapping. We conclude that only 11 of the labeled bands are contributed by flagellar polypeptides; the remaining five bands are shown to be contaminants from the cell wall, and additional cell-wall polypeptides are found to co-migrate with flagellar species. A polypeptide designated as a possible membrane tubulin in preliminary studies is shown here to be different from tubulin in its peptide map. The 11 polypeptides assigned as specific flagellar surface components are candidate participants in such biological events as sexual adhesion, flagellar surface motility, and sensory signalling.

Calcium-entry blockers and cardiovascular disease

The beneficial effects of calcium-entry blockers in the treatment of ischemia in the heart and in other tissues can be explained by (1) relaxation of venous smooth muscle, in particular that of the splanchnic veins; (2) negative inotropic effect on the myocardial cells; (3) negative chronotropic effects on the heart; (4) inhibition of vasospastic episodes in coronary and other large arteries; (5) depression of myogenic activity and responsiveness to vasconstrictor stimuli in precapillary resistance vessels; (6) inhibition of platelet aggregation; (7) possible increases in the deformability of hypoxic red blood cells; (8) protection of endothelial integrity and function; and (9) protection of the body cells, in particular myocardial cells, from prolonged exposure to anoxia and from massive entry of calcium during reperfusion. In the case of angina pectoris, the effects on the myocardial cells themselves, the decrease in preload and afterload, and the improvement of coronary perfusion combine to allow the heart to perform more work before an imbalance is reached between the metabolic demands of the myocardial cells and their blood supply. The increased myocardial performance may favor collateral circulation and withdrawal of the reflex load upon the heart, originating from the ischemic myocardium. The available calcium-entry blockers vary in their potency to affect the different components of the cardiovascular system.

Inhibitory role of the endothelium in the response of isolated coronary arteries to platelets

Aggregating autologous platelets caused contraction of isolated rings of canine left circumflex arteries. The contractions were augmented after removal of the endothelium and were attenuated by serotonergic antagonists. During contraction caused by prostaglandin F2 alpha, aggregating platelets caused a transient increase in tension followed by a profound relaxation of arteries with endothelium, but caused only further contraction of arteries without endothelium. These observations demonstrate the importance of the vascular endothelium in opposing the constriction of coronary vessels caused by 5-hydroxytryptamine and other substances released from aggregating platelets.

Sonographic diagnosis of cystic adenomatoid malformation in-utero

Routine ultrasound examination at 30 weeks gestation revealed an intrapulmonary cystic mass in an otherwise normal fetus. Following delivery at term, the diagnosis of congenital cystic adenomatoid malformation of the right lung was confirmed, and an elective right middle lobectomy successfully performed at nine days of age.

Psychophysiological response patterns in vascular and muscle-contraction headaches

The psychophysiological response patterns of 43 headache subjects were compared to the response patterns of 11 nonheadache control subjects. The headache group was composed of subjects diagnosed as suffering from either muscle-contraction (N = 11), classic migraine (N = 11), common migraine (N = 11), or mixed (N = 10) headache. Discriminant analyses indicated that (1) the headache groups could be perfectly differentiated from the nonheadache control group after a period of relaxation and during a period of psychological stress and (2) the stress condition differentiated among the various headache groups. In general, the headache groups showed a higher level of arousal and were more responsive to stress. Also, the response pattern profiles differed among the headache groups in the stress condition. Muscle-contraction subjects tended to respond with higher frontal EMG, and classic migraine and mixed headache groups tended to respond with larger cardiovascular responses.

Prejunctional and postjunctional actions of endogenous norepinephrine at the sympathetic neuroeffector junction in canine coronary arteries

The effects of endogenous and of exogenous norepinephrine were studied in isolated rings of canine left circumflex coronary artery and its first ventricular branch. Norepinephrine was released from adrenergic nerve endings by transmural electrical stimulation and by tyramine. In rings contracted with prostaglandin F2 alpha, transmural electrical stimulation resulted in frequency-dependent relaxations which were blocked by propranolol or tetrodotoxin; tyramine and exogenous norepinephrine caused concentration-dependent relaxations which were blocked by propranolol. The tyramine-induced relaxations also were inhibited by cocaine. The left circumflex artery was less sensitive than its branch to beta-adrenergic activation; this difference was significant even between rings of the two vessels immediately adjacent to the branching point and was abolished by phentolamine. In the presence of propranolol, transmural electrical stimulation, tyramine and phenylephrine, produced contractions of the left circumflex artery, but not the branch; these contractions were prevented by phentolamine. Phentolamine, but not prazosin, augmented the beta-adrenergic response of left circumflex artery to low frequency stimulation; in arteries preincubated with 3H-norepinephrine, this was accompanied by an increased overflow of tritiated neurotransmitter. The prejunctional effect of phentolamine was also evident in branch coronary arteries which exhibit no postjunctional alpha-adrenergic responses. With high frequency stimulation, both alpha-adrenergic antagonists equally augmented the relaxation of left circumflex artery; the efflux of tritiated norepinephrine was not different from untreated arteries. These experiments demonstrate, in isolated coronary arteries, that the primary adrenergic response to released endogenous norepinephrine is beta-adrenergic relaxation. The prejunctional effects of nonspecific alpha-adrenergic antagonists preclude their use in determining the importance of postjunctional coronary alpha-adrenergic receptor activation caused by sympathetic nerve stimulation.

Non-neurogenic inhibitory effect of electrical impulses in isolated canine coronary arteries

Electrical stimulation caused frequency-dependent reversible relaxations of canine coronary arteries made to contract with prostaglandin F2 alpha, phenylephrine, 5-hydroxytryptamine, potassium chloride, or angiotensin II. These contractions were not affected by cold storage, tetrodotoxin, alpha- and beta-adrenergic blockade and atropine, demonstrating that they probably are not due to activation of inhibitory nerves. The relaxations persisted in the presence of indomethacin and after removal of the endothelium. They were not seen in splenic arteries and saphenous veins, demonstrating the high sensitivity of the coronary blood vessel wall to the inhibitory effects of the electric impulses.

Frieda Fromm-Reichmann: a seminar in the history of psychiatry. II. Notes on the life and work of Frieda Fromm-Reichmann

It is now 25 years since Frieda Fromm-Reichmann died--over 30 years since she published her only book. Principles of Intensive Psychotherapy. Most of those who now attend the presentations of the annual research award of the Academy or the annual lectures of the Washington School of Psychiatry, both of which are named in her honor, never saw her. It seems appropriate to ask whether she still speaks to us today, whether in any significant way she influenced the development of what is now common practice in our field.

Beta-adrenergic vasodilator mechanism in the finger

The digital vasospastic phenomena, which are induced by beta-adrenergic-blocking agents, suggest a beta-adrenergic finger vasodilator mechanism. We measured fingertip total blood flow with venous occlusion plethysmography and studied nutritional blood flow with Na131I clearance. During fingertip vasoconstriction caused by branchial artery infusion of norepinephrine or angiotensin, intra-arterial isoproterenol caused a sustained increase in fingertip total blood flow. Furthermore, propranolol significantly potentiated the vasoconstriction caused by intra-arterial norepinephrine and attenuated the vasodilator action of isoproterenol. No change in branchial artery blood pressure occurred to explain the changes in fingertip blood flow. Isoproterenol did not change nutritional flow, implying beta-adrenergic vasodilation solely of the fingertip arteriovenous shunts. When fingertip vasoconstriction was induced by reflex sympathetic nerve action during environmental cooling and mental stress, or by norepinephrine release from sympathetic nerves caused by intra-arterial tyramine infusion, isoproterenol and propranolol had no effect on fingertip total blood flow. This effect is probably specific for the beta-receptor agonist, since intra-arterial histamine caused a large increase in finger blood flow during environmental cooling. We conclude that there is a beta-adrenergic vasodilator mechanism in human digital arteriovenous shunts that may be humorally activated, but which has no apparent functional role in modulating sympathetic vasoconstriction. Our results suggest a spatial dissociation of the effector sites for vasoactive humoral agents and sympathetic vasoconstrictor nerves.

Diurnal levels of immunoreactive erythropoietin in normal subjects and subjects with chronic lung disease

Serum levels of immunoreactive erythropoietin (Ep) were measured in 48 normal male and female volunteers, ages 20-60 years, to establish a control value for Ep of 18.5 +/- 5.0 (mean +/- SD) mU/ml. Levels of the hormone were also measured sequentially over a 24 h period of time in an additional 17 'normal' volunteers with no diurnal variation. Diurnal levels of immunoreactive Ep were also measured in 30 subjects, with chronic lung disease. These patients, in contrast to normal subjects exhibited a diurnal variation in the level of immunoreactive Ep with peak levels occurring at midnight. The only variable measured which correlated with the serum immunoreactive Ep level in subjects with chronic lung disease was the level of carboxyhaemoglobin (P less than 0.02).

Regulatory mechanism of erythropoietin production: effects of hypoxemia and hypercarbia

The purpose of this study was twofold: (1) to define the relationship between erythropoietin (Ep) production and some of the coincident variables which control oxygen delivery in hypoxic and hypoxic-hypercarbic rats (2) to define the mechanism whereby hypercarbia suppresses Ep production in hypoxemic rats. Rats were exposed to O2 concentrations ranging from 5% to 9% O2 for either 3 or 16 h. Arterial whole blood pH, pCO2, pO2, O2 saturation, p50 and Ep levels were measured in each rat. There was a highly significant inverse correlation between both the arterial pO2 and O2 saturation and the Ep level. Ep levels were not increased above normal if the pO2 was greater than 50 mm Hg or the O2 saturation was greater than 80%. The addition of 5% CO2 to all inhaled gas mixtures was associated with a 10 mm Hg increment in the pO2 together with a marked reduction in plasma Ep levels. Of the measured variables only the pO2 and O2 saturation showed a consistent correlation with the Ep levels when rats exposed to hypoxia were compared with rats exposed to hypoxia + CO2.

Effect of morphine on limb capacitance and resistance vessels

1. The actions of 15 mg of intravenous morphine on hand and forearm capacitance and resistance vessels were studied with venous occlusion plethysmography. 2. In contrast to a 5% increase in forearm venous volume, intravenous morphine caused a 26% decrease in hand venous volume. This hand venoconstriction was confirmed by finding an increase in hand venous tone. The effects of morphine on hand veins were attenuated by intraarterial phentolamine and blocked by intravenous naloxone. 3. Whereas morphine had no significant effect on forearm resistance vessels, it caused a 70% reduction in hand vascular resistance. 4. Intra-arterial morphine had no local action on hand capacitance or resistance vessels. 5. Though the contrasting actions of morphine on hand and forearm capacitance vessels resulted in no important change in limb venous capacitance, the large reduction of cutaneous vascular resistance may contribute to haemodynamic benefit in patients with pulmonary oedema.

Naloxone reversal of morphine-induced peripheral vasodilatation

Naloxone is used to reverse the central nervous system amd respiratory depressant effects of morphine, but it is not known whether the narcotic antagonists also reverses the peripheral vasodilatation. Since the cutaneous vasodilatation induced by morphine may be hemodynamically important in cardiac patients, we studied the effect of naloxone on the morphine-induced vasodilatation in the cutaneous vascular bed of the hand using venous occlusion plethysmography. Morphine, 15 mg intravenously, caused a 70% reduction in hand vascular resistance. Given 18 min after morphine, naloxone, 0.8 mg intravenously, completely reversed the vasodilatation in 12 to 17 min. Saline placebo given 18 min after morphine induced no reversal; the vasodilatation lasted at least 35 min. Naloxone acts as a pure antagonist to these actions of morphine, since it has no actions on blood flow in the hand when given alone.

Diagnostic problems of partially treated Whipple's disease. Report of a case with isolated deficiency of immunoglobulin M

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