Forearm Of Man Research Articles

The effect of intra‐arterial endothelin on resting blood flow and sympathetically mediated vasoconstriction in the forearm of man.

1. The hypothesis that endothelin (ET) influences sympathetically mediated vasoconstriction was investigated in 13 healthy, male subjects. 2. ET (1 pmol min-1) was infused for 60 min into the left brachial arteries of seven healthy male subjects. Resting forearm blood flow, and sympathetic vasoconstriction produced by lower body negative pressure (LBNP; 15 mm Hg), was measured in both arms by strain gauge plethysmography. In a further six subjects, noradrenaline (NA) was infused intra-arterially at doses of 150-600 pmol min-1, with and without co-infusion of ET (1 pmol min-1), with blood flow measured in both forearms. 3. ET produced a small but significant reduction of blood flow in the infused forearm from 3.9 +/- 0.6 ml 100 ml-1 min-1 during infusion of saline, to 3.3 +/- 0.7 ml 100 ml-1 min-1 during infusion of ET at 60 min (P less than 0.05). Blood flow in the non-infused forearm was not altered by ET infusion. 4. NA produced a significant and dose-dependent reduction of blood flow in the infused forearm from 3.13 +/- 0.5 ml 100 ml-1 min-1 during saline infusion, to 1.49 +/- 0.2 ml 100 ml-1 min-1 with NA at 600 pmol min-1 (P less than 0.001). During co-infusion of ET, blood flow was reduced similarly in the infused arm from 3.15 +/- 0.7 ml 100 ml-1 min-1 during saline infusion to 1.55 +/- 0.2 ml 100 ml-1 min-1 with NA at 600 pmol min-1. Blood flow in the non-infused arm was not altered by ET and NA infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics of glucose disposal in whole body and across the forearm in man.

We reevaluated the concept that the in vivo glucose disposal rate in man is determined by the activity of the glucose transport system. Rates of glucose disposal were determined in whole body and across forearm at four insulin levels (approximately 9, approximately 50, approximately 160, and approximately 1700 microU/ml) and at each insulin level at four glucose levels (approximately 90, approximately 160, approximately 250, and approximately 400 mg/dl). At the lowest insulin level, the Michaelis constants (Ks:s) for glucose disposal in whole body (8.7 +/- 1.1 mM) and across forearm (7.4 +/- 1.4) mM) were compatible with a Ks determined in vitro for the transport system. At higher insulin levels, the apparent Ks increased significantly in whole body (16.2-37.7 mM) and across forearm (20.7-31.2 mM). We interpret the apparent increase of Ks by insulin to reflect a shift in the rate-limiting step from glucose transport to some step beyond transport.

The Long Childhood

began about AD 900, before Christianity arrived, at a time when China was a great empire, and Europe was the spoil of princelings and robber barons. That is a remarkable beginning to democracy. But there is something more remarkable about this misty, inclement site. It was chosen because the farmer who had owned it had killed, not another farmer but a slave, and had been outlawed. Justice was seldom so even-handed in slave-owning cultures. Yet justice is a universal of all cultures. It is a tightrope that man walks, between his desire to fulfil his wishes, and his acknowledgement of social responsibility. No animal is faced with this dilemma: an animal is either social or solitary. Man alone aspires to be both in one, a social solitary. And to me that is a unique biological feature. That is the kind of problem that engages me in my work on human specificity, and that I want to discuss. It is something of a shock to think that justice is part of the biological equipment of man. And yet it is exactly that thought which took me out of physics into biology, and that has taught me since that a man's life, a man's home, is a proper place in which to study his biological uniqueness. It is natural that by tradition biology is thought of in a different way: that the likeness between man and the animals is what dominates it. Back before the year AD 200 the great classic author of antiquity in medicine, Claudius Galen, studied, for example, the forearm in man. How did he study it? By dissecting the forearm in a Barbary ape. That is how you have to begin, necessarily using the evidence of the animals, long before the theory of evolution comes to justify the analogy. And to this day the wonderful

Insulative power of body fat on deep muscle temperatures and isometric endurance.

Four male subjects were examined to assess the relationship of body fat content to deep muscle temperature and the endurance of a fatiguing isometric handgrip contraction at a tension set at 40% MVC. Muscle temperature was altered by the immersion of the forearm in water at temperatures varying from 7.5 to 40 degrees C. In all subjects, there was a water bath temperature above and below which isometric endurance decreased markedly; the difference among individuals was solely accounted for by the individual's body fat content. Thus, subjects with higher body fat content required lower bath temperatures to cool the forearm musculature to its optimum temperature, which we found to always be approximately 27 degrees C measured 2 cm perpendicularly to the skin in the belly of the brachioradialis muscle. Further, in one subject, we found that a reduction in this subject's body fat content resulted in a corresponding increase in the water bath temperature necessary to cool his muscles to their optimum isometric performance. The data demonstrate the striking insulative power of the thin layer of fat around the forearm in man in protecting shell tissues from cold exposure.

Antilipolytic effect of digoxin in the forearm of man.

The effects of intra-arterial infusions of digoxin 0.1 μg/min for 30 min on metabolism of the perfused forearm were studied. Infusion of digoxin in 4 subjects did not significantly alter forearm blood flow, oxygen consumption, vascular resistance, lactate production or arterio-venous differences for free fatty acids; however, glucose uptake was significantly increased. Infusion of epinephrine 0.1 μg/mg for 45 min in 4 subjects increased forearm blood flow, reduced forearm vascular resistance and significantly increased lactate production from forearm muscle and free-fatty acid loss from forearm adipose tissue. Infusion of epinephrine 0.1 μg/min for 45 min in 4 subjects after the 30-min infusion of digoxin resulted in similar increases in forearm blood flow and lactate production as with the epinephrine infusions alone; however, arterio-venous differences for free fatty acids were significantly reduced. Prior infusion of digoxin also inhibited the lipolysis but not the glycolysis associated with epinephrin...

Effect of adrenaline iontophoresis on capillary filtration in the forearm of man.

Capillary filtration rate and capillary filtration coefficient have been measured in the forearm of man in control limbs and in limbs subjected to iontophoresis of adrenaline to minimize superficial blood flow. Gross reduction in the rates of tissue fluid accumulation occurred in the iontophoresed limbs. It is concluded that the skin and subcutaneous tissues—that is, the tissues whose vessels are accessible to vasoconstriction by adrenaline administered by ion transfer—are the major site for accumulation of extracellular fluid in the forearm in man.

The quantitative estimation of toluene skin absorption in man.

The absorption of toluene through the skin of the hand and the forearm in men was investigated experimentally. Both the absorption of liquid toluene and the absorption from aqueous solutions were studied using the direct method. It was stated that under the experimental conditions the rate of absorption of liquid toluene was 14–23 mg/cm2/h. In mean concentrations of 180–600 mg/1 the rate of absorption of toluene from aqueous solutions was 160-600 μg/cm2/h and increased according to the increase of toluene concentration.

A study of the skin absorption of ethylbenzene in man.

The absorption of ethylbenzene through the skin of the hand and the forearm in men was investigated experimentally. Both the absorption of liquid ethylbenzene and the absorption from aqueous solutions were studied. The rate of absorption of liquid ethylbenzene was 22 to 33 mg./cm.²/hr, and the rates from aqueous solutions were 118 and 215 μg./cm.²/hr from mean concentrations of 112 and 156 mg./litre. The mandelic acid excreted in urine was equivalent to about 4·6% of the absorbed dose—much less than after lung absorption. Urinary mandelic acid does not provide a reliable index of absorption when there is simultaneous skin and lung exposure.

Reflex Vasoconstrictor and Vasodilator Responses in Man

The application of ice to the forehead and the Valsalva maneuver are known to cause reflex vasoconstriction by stimulation of adrenergic pathways of the sympathetic nervous system. In the experiments reported here, the effects of these stimuli on blood flow to the forearm of man were studied after intra-arterial injection of adrenergic blocking drugs. Changes in flow were measured with water plethysmographs applied to both forearms. One forearm served as "control," and the other forearm, into which the drugs were injected, was the "experimental" one. The stimuli caused a consistent reduction of flow to the control forearm, but after the intra-arterial infusion of small doses of guanethidine there was increased flow to the experimental arm simultaneous with decreased flow to the control arm. The increased flow in response to the stimuli was accentuated after phentolamine and reduced after atropine. The results indicate that the application of ice to the forehead and the Valsalva maneuver stimulate adrenergic vasoconstrictor pathways and cholinergic vasodilator pathways simultaneously. The vasoconstrictor response predominates, and the vasodilator effect is unmasked only after adrenergic blockade. It appears, therefore, that mental stresses are not the only stimuli which can cause reflex cholinergic vasodilatation in the forearm of man. Work by others would suggest that leg exercise may also cause cholinergic dilatation after adrenolytic agents. It is possible that cholinergic vasodilatation may play a role in the severe orthostatic fall in blood pressure, as well as in the exercise hypotension, observed in patients treated with guanethidine.

EFFECT OF HUMAN GROWTH HORMONE ON MUSCLE AND ADIPOSE TISSUE METABOLISM IN THE FOREARM OF MAN.

EFFECT OF HUMAN GROWTH HORMONE ON MUSCLE AND ADIPOSE TISSUE METABOLISM IN THE FOREARM OF MAN.

アズレン合剤による皮膚粘膜障害の予防的治験 : とくに亜砒酸工場での成績

Ointments composed of azulen dehydroxyacetate and carboxymethyl-cellulose (A-CMC) or polyvinyl-pyridin (A-PVC) were used for cure and prevention of disorders of the skin and the mucous membrane. 1. By application of A-CMC, time of disappearance of dermatographic signs on the forearm of man was shortened, and dermatitis of rabbits by arsenites was prevented. 2. Application of A-PVP to the eye of rabbits, of which conjunctiva were made hyperemic and edematous by abrasion, caused more rapid disappearance of these symptoms without any side-effects. No side-effects were also observed in repeated applications to the nasal mucous membrnane of new-born infants. 3. The application of A-PVP to the nasal mucous membrane did not affect its excreting functions, and it prolonged the duration of enhanced air passage. 4. Inhalation of A-PVP prevented or cured inflammation of the respiratory tract of rabbits. 5. In arsenite plants, application of A-CMC decreased morbidity of dermatitis, and application of A-PVP not only cured cases of conjunctivitis and inflammation of the upper respiratory tract but also decreased their incidence. PVP as well as CMC, as high-molecular amphoteric substances, have non-osmotic protective effects due to its adsorptive, imbibitive and other characteristics. These effects combined with antiphlogistic and anti-allergic effects of azulen seem to provide excellent ointments not inferior to the existing ones for cure and prevention of disorders of the skin and the mucous membrane.

A METABOLIC REGULATING DEVICE BASED ON THE ACTIONS OF HUMAN GROWTH HORMONE AND OF INSULIN, SINGLY AND TOGETHER, ON THE HUMAN FOREARM.

THERE have been several reports from the laboratories of F. G. Young (Ketterer, Randle and Young1, Korner and Manchester2, Korner3) suggesting that growth hormone directs the action of insulin on muscle ‘away from carbohydrate toward protein synthesis’. Although some of the intimate detail of the proposed hypothesis concerning growth hormone action may be erroneous, the basic notion, as advanced by Korner3, that, in the presence of growth hormone, some actions of insulin are preserved, whereas other effects are blunted, is very attractive. Placed in juxtaposition to observations from this laboratory on the effects of close intra-arterial injection of insulin and of human growth hormone, singly and together, on muscle and adipose tissue metabolism in situ in the forearm of man, it provides a clearer picture of the day-to-day role of human growth hormone and of insulin, and thus of their place in the economy of the normal adult.

Effect of insulin on carbohydrate metabolism and on potassium in the forearm of man.

We have described a technique for quantifying skeletal muscle metabolism in man in. situ by measing blood flow through the forearm and appropriate arteriovenous differences in concentration of selected metabolites ( 1 ). The technique lends itself to analysis of local effects of hormones and other possibly potent agents. The agent can be injected into the brachial artery at constant rate with the solution of Evans blue dye used to measure blood flow. The quantity of the agent injected can be sufficiently large to exert a measurable effect in the forearm but sufficiently small so that, upon approximately 100-fold dilution when forearm venous effluent mixes with blood in the heart and great vessels, there is no measurable systemic effect. There are, therefore, no detectable systemic counter-regulatory processes set in motion by the agent to complicate the primary response of the forearm to the agent itself. It is the purpose of this report to describe the effects on forearm muscle metabolism of insulin administered in this fashion. We sought information concerning the following two problems.

Effect of mephentermine on venomotor tone, blood flow and arterial pressure in forearm of man.

SummaryForearm blood flow and venomotor responses to intravenous injection of mephentermine were studied in normal men. In each experiment blood flow decreased while arterial pressure increased. Venous pressure increased while forearm venous distensibility and venous volume decreased in each subject. In each case blood shifted from the forearm. These experiments indicate that mephentermine administration increases both peripheral resistance and venous tone in man.

Effect of bladder distension on the venous system of man.

SummaryVenomotor responses of an intact isolated superficial venous segment of the forearm of man to bladder distension showed that instillation of 50 cc of fluid into the empty bladder resulted in an increase in venous pressure and venomotor tone. The increase in segmental venous pressure could be inhibited by regional procaine block. The response was absent in a patient with complete transection of the spinal cord. Thus, distension of the urinary bladder initiates a spinal venomotor reflex which produces an increase in peripheral venous tone in the superfacial veins of the forearm of man.

Rates of transfer of Rb 86, K 42, K 39, Cl 36, Cl 35, Na 22, and Na 23 across a blister surface on the forearm of normal man and patients with chronic congestive heart failure

The base of a cantharides blister on the forearm of man was utilized as a living membrane for the study of kinetics of electrolyte transfer. This preparation provided a readily reproducible and reliable model for such studies. Studies were made of transfer of Na 23, Na 22, Cl 35, Cl 36, K 39, K 42 and Rb 86 both into and out of the experimental extracorporeal compartment. Since the electrolytes and radioisotopes entered and left the extracorporeal compartment by way of capillaries, this model provided an approach to the study of transfer across capillary walls without the limitations of circulation and mixing which interfere with such studies from within the vascular tree. Transcapillary transfer of electrolytes was found to be very rapid. Estimation of the amount of electrolytes crossing the capillaries of man per day revealed enormous amounts: sodium chloride 60,000 lb and potassium 1900 lb at normal seral concentrations.

Study of the venomotor state in a short intact venous segment of the forearm of man

Study of the venomotor state in a short intact venous segment of the forearm of man

Measurement of blood flow and volume in the forearm of man; with notes on the theory of indicator-dilution and on production of turbulence, hemolysis, and vasodilatation by intra-vascular injection.

Measurement of blood flow and volume in the forearm of man; with notes on the theory of indicator-dilution and on production of turbulence, hemolysis, and vasodilatation by intra-vascular injection.

Transcapillary exchange rates of deuterium oxide and thiocyanate in the forearm of man.

For this hemodynamic study, Freis's team devised a method for determining the net bidirectional exchange of substances permeable to the capillary walls of the human forearm, using T-1824 (a dye that binds to plasma protein), sodium thiocyanate, and deuterium oxide (heavy water). They were then able to learn the rate at which water moves between body tissues and capillaries in cell metabolism.

The Synthesis of Some New Esters of p-Carboxybenzamidine

Because it had previously been shown that some of the simple n-alkyl-p-carboxybenzamidines possessed significant local anesthetic activity, several new esters were prepared in order to test their activities. Representative examples of halogenated alcohols, aromatic alcohols, and cyclohexanol were chosen for the alcohol portion of the molecule. Several of these new esters were more active than both cocaine when instilled in guinea-pig eyes and procaine when administered intracutaneously in guinea-pig skin. Toxicities were favorable; however, they produced an undesirable pruritis when injected in the forearm of man.