Pressor responses to norepinephrine in humans before and after corticosteroids

1962 ◽  
Vol 203 (5) ◽  
pp. 961-963 ◽  
Author(s):  
Mohinder P. Sambhi ◽  
Max H. Weil ◽  
Vasant N. Udhoji
Keyword(s):  
Human Subject ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Variance Analysis ◽  
Acute Administration ◽  
Intravenous Injections ◽  
Pressor Responses ◽  
Before And After

Pressor responses produced by intravenous injections of graded doses of norepinephrine were recorded in ten normal subjects before and after pharmacologic doses of glucocorticoids. Two subjects had been pretreated with 9α-fluorocortisol. Although a considerable variation was found in the responsiveness to repeated norepinephrine injections, variance analysis demonstrated that administration of adrenal cortical hormones and their analogues did not significantly alter the response. These observations do not support the hypothesis that acute administration of corticosteroids in large doses potentiates the pressor effects of catecholamines in the human subject with normal adrenal function.

DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Function Test ◽  
Before And After ◽  
Adrenal Response ◽  
Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

Aminophylline and human diaphragm strength in vivo

1990 ◽  
Vol 68 (6) ◽  
pp. 2591-2596 ◽  
Author(s):  
R. D. Levy ◽  
S. Nava ◽  
L. Gibbons ◽  
F. Bellemare
Keyword(s):  
Motor Units ◽  
Normal Subjects ◽  
Acute Administration ◽  
Transdiaphragmatic Pressure ◽  
Gastric Pressure ◽  
Significant Difference ◽  
Before And After ◽  
Normal Human ◽  
Twitch Characteristics

The transdiaphragmatic pressure (Pdi) twitch response to single shocks from supramaximal bilateral phrenic nerve stimulation was studied before and after acute intravenous infusions of aminophylline [14.9 +/- 3.1 (SD) micrograms/ml] in nine normal subjects. Stimulation was performed with subjects in the sitting position against an occluded airway from end expiration. Baseline gastric pressure and abdominal and rib cage configuration were kept constant. There was no significant difference in peak twitch Pdi from the relaxed diaphragm between control (38.8 +/- 3.3 cmH2O) and aminophylline (40.2 +/- 5.2 cmH2O) experiments. Other twitch characteristics including contraction time, half-relaxation time, and maximum relaxation rate were also unchanged. The Pdi-twitch amplitude at different levels of voluntary Pdi was measured with the twitch occlusion technique, and this relationship was found to be similar under control conditions and after aminophylline. With this technique, maximum Pdi (Pdimax) was calculated as the Pdi at which stimulation would result in no Pdi twitch because all motor units are already maximally activated. No significant change was found in mean calculated Pdimax between control (146.9 +/- 27.0 cmH2O) and aminophylline (149.2 +/- 26.0 cmH2O) experiments. We conclude from this study that the acute administration of aminophylline at therapeutic concentrations does not significantly affect contractility or maximum strength of the normal human diaphragm in vivo.

On the role of dopamine receptors in the central regulation of human TSH

1981 ◽  
Vol 98 (4) ◽  
pp. 521-527 ◽  
Author(s):  
G. Delitala ◽  
L. Devilla ◽  
A. Canessa ◽  
F. D'Asta
Keyword(s):  
Dopamine Receptors ◽  
Blood Brain Barrier ◽  
Median Eminence ◽  
Normal Subjects ◽  
Acute Administration ◽  
Central Regulation ◽  
Before And After ◽  
Tsh Secretion ◽  
Substituted Benzamides

Abstract. The effects of acute administration of haloperidol (4 mg im) and pimozide (4 mg orally) on TSH and Prl secretion were studied in normal and hypothyroid man. The TRH-induced TSH secretion before and after pre-medication with pimozide and domperidone, a peripheral dopamine (DA) blocker, was also evaluated in a group of normal subjects. Haloperidol and pimozide induced a marked increment in serum Prl; mean Prl levels were still significantly elevated 12 h following pimozide administration. A small but significant TSH increase was observed following haloperidol and pimozide in normal as well as hypothyroid subjects. Both domperidone and pimozide significantly enhanced TRH-induced TSH release. In another experiment 3 women with primary thyroid failure received an infusion of DA (4 (μg/kg/min for 4 h) with and without domperidone administration. TSH and Prl levels were suppressed by DA, but the effect was completely abolished by domperidone. The results suggest that psychotrophic drugs, such as haloperidol and pimozide, can, like substituted benzamides, stimulate TSH release in man. Since domperidone and DA do not cross the blood-brain-barrier and domperidone significantly enhanced the TSH response to TRH, the data also support the hypothesis that human TSH is regulated by DA at the hypothalamus (median eminence) and/or pituitary level.

Cardiovascular Reactivity in the Dog after Chemical Sympathectomy with 6-Hydroxy dopamine

1974 ◽  
Vol 52 (3) ◽  
pp. 590-601 ◽  
Author(s):  
Pierre Gauthier ◽  
Réginald A. Nadeau ◽  
Jacques De Champlain
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Reactivity ◽  
Blood Pressure Response ◽  
Cardiovascular Responses ◽  
Chemical Sympathectomy ◽  
Intravenous Injections ◽  
Pressor Responses ◽  
Before And After ◽  
Anesthetized Dogs ◽  
6 Hydroxydopamine

The cardiovascular responses to intravenous injections of noradrenaline, isoproterenol, and phenylephrine were studied in unanesthetized and anesthetized dogs before and after chemical sympathectomy with 6-hydroxydopamine (6-OH-DA), 50 mg/kg. Three days after 6-OH-DA pretreatment, the blood pressure response to noradrenaline in unanesthetized dogs was increased significantly despite the presence of a marked reflex slowing of the heart. Chronotropic and pressor responses to noradrenaline were likewise increased in anesthetized and vagotomized dogs after 6-OH-DA pretreatment. Not only was the amplitude of the responses to noradrenaline increased after 6-OH-DA pretreatment but their duration was likewise prolonged. In contrast, the cardiovascular responses to isoproterenol and phenylephrine did not appear significantly changed in 6-OH-DA pretreated dogs. These results are consistent with the development of a presynaptic type of supersensitivity in dogs pretreated with 6-OH-DA.

Interaction of captopril and ibuprofen on glomerular and tubular function in humans

1990 ◽  
Vol 259 (2) ◽  
pp. F233-F238
Author(s):  
M. Allon ◽  
C. B. Pasque ◽  
M. Rodriguez
Keyword(s):  
Renal Plasma Flow ◽  
Urine Volume ◽  
Normal Subjects ◽  
Acute Administration ◽  
Distal Nephron ◽  
Water Diuresis ◽  
Water Handling ◽  
Patients With Heart Failure ◽  
Before And After ◽  
Opposing Effects

Renal hemodynamics and tubular solute and water handling were evaluated in normal subjects during water diuresis, before and after the acute administration of captopril, ibuprofen, or the combination of both drugs. The glomerular filtration increased after captopril administration but did not change after ibuprofen alone or in combination with captopril. Renal plasma flow increased with captopril alone and captopril plus ibuprofen but did not change after ibuprofen alone. Urine volume and Na excretion increased with captopril and decreased after ibuprofen; coadministration of ibuprofen attenuated the tubular effects produced by captopril alone. FELi, fractional delivery of solute to the distal nephron, and FELi-FENa, fractional distal reabsorption of solute, both significantly increased after captopril and decreased after ibuprofen but did not change with the combined regimen. (FELi-FENa)/FELi, fractional reabsorption of distally delivered Na, significantly decreased after captopril and increased after ibuprofen but remained unchanged after captopril plus ibuprofen. Thus captopril and ibuprofen have opposing effects on tubular Na and water handling, which are attenuated by the addition of the other drug. This interaction may have clinical relevance in patients with heart failure or hypertension, in whom captopril is used to enhance Na and water diuresis.

The Effect of Stapedectomy on the Loudness of One’s Own Voice

1965 ◽  
Vol 8 (3) ◽  
pp. 223-234 ◽  
Author(s):  
William Melnick
Keyword(s):  
Middle Ear ◽  
Normal Subjects ◽  
Sound Energy ◽  
Loudness Function ◽  
Before And After ◽  
Increased Sensitivity

Five subjects with normal middle ear mechanisms, and otosclerotic patients, before and after stapedectomy, matched the loudness of their voices to the loudness of a 125-cps-sawtooth noise. The results showed loudness matching functions with gradual slopes, less than 1.00, for the normal subjects and the patients prior to stapedectomy. Post-surgically, the loudness function for the patients increased in steepness to considerably more than 1.00. These results are explained, most logically, in terms of increased sensitivity of the altered middle ear to sound energy generated by the listener’s own voice.

BESTIMMUNG DER INSULINAKTIVITÄT IM MENSCHLICHEM SERUM NACH GLUKOSEBELASTUNG ALS PRÜFUNG DER FUNKTIONSFÄHIGKEIT DES PANKREAS

1963 ◽  
Vol 42 (3) ◽  
pp. 437-452 ◽  
Author(s):  
H. Daweke
Keyword(s):  
Blood Sugar ◽  
Pancreatic Insufficiency ◽  
Normal Subjects ◽  
Insulin Binding ◽  
Epididymal Adipose Tissue ◽  
Moderate Increase ◽  
Glucose Loading ◽  
Before And After ◽  
Oral Hypoglycaemic Drugs ◽  
Severity Of The Disease

Using the method of glucose-1-14C oxydation to 14CO2 on the rat epididymal adipose tissue, the insulin-like activities (ILA) in the serum have been compared before and after oral loading with glucose in normal subjects, in maturity-onset diabetics and in insulin-requiring diabetics. In maturity-onset diabetics mean fasting values were found to be 30% below normal while in insulin-requiring diabetics they were 85% above normal. In normal subjects there was observed, 30 minutes after glucose loading, a moderate increase in blood sugar together with an increase of ILA of 222% above the starting value; in maturity-onset diabetics the increase in ILA was only 106% while the blood sugar was markedly increased. After glucose loading in maturity-onset diabetics, the total amount of insulin detected during the period of the experiment was, on the average, only 45% of that found in normal subjects. In insulin requiring diabetics there was no increase but, on the contrary, a steady decrease of the ILA values, while the blood sugar excessively increased. In general ILA values were higher than those in maturity-onset diabetics. No difference in response was found between maturity-onset diabetics treated with diet alone and those treated with diet and oral hypoglycaemic drugs. In contrast to the absolute ILA values, the index of insulin reserve, is of value in assessing the functional capacity of the pancreas. This index decreases progressively with the severity of the disease and reaches a maximum of 54% of the normal in maturity-onset diabetics, which can satisfactorily be explained by pancreas insufficiency. Only in some cases of insulin-requiring diabetics was an insulin reserve still detectable. The biological inactivity of the insulin circulating in the blood can be deduced from the increased ILA-values, as compared with those found in maturity-onset diabetics. Obviously some of this insulin can be released by the addition of glucose. It is likely that, in addition to pancreatic insufficiency, insulin-binding or insulin-inactivating antibodies play a part in the pathogenesis of insulin-requiring diabetes.

Usefulness of plasma pregnenolone sulfate in testing pituitary-adrenal function in children

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S259-S263 ◽  
Author(s):  
E. de Peretti ◽  
M.G. Forest ◽  
B. Loras ◽  
Y. Morel ◽  
M. David ◽  
...  
Keyword(s):  
Normal Subjects ◽  
Adrenal Function ◽  
Pituitary Function ◽  
First Year ◽  
Dynamic Tests ◽  
Pregnenolone Sulfate ◽  
Pituitary Diseases ◽  
First Year Of Life ◽  
Dexamethasone Suppression ◽  
Abrupt Rise

SUMMARY In normal subjects, plasma pregnenolone sulfate (PS) levels high at birth, decreased during the first year of life in relation to the pattern of involution of the fetal adrenal zone. Thereafter, PS levels, in contrast with those of DHAS, did not show the abrupt rise characteristic of the adrenarche, but increased very progressively till adulthood. The response of PS to various provocative tests of adrenal and pituitary function (ACTH and Metyrapone stimulation, dexamethasone suppression), has been established in normal subjects. The measurement of plasma PS levels in basal conditions as well as in response to dynamic tests was very useful in the diagnosis of various adrenal and pituitary diseases in children.

Effects of adaptation of vestibulo-ocular reflex function on manual target localization

2000 ◽  
Vol 10 (2) ◽  
pp. 75-86 ◽  
Author(s):  
Jacob J. Bloomberg ◽  
Lauren A. Merkle ◽  
Susan R. Barry ◽  
William P. Huebner ◽  
Helen S. Cohen ◽  
...  
Keyword(s):  
Adaptive Modulation ◽  
Normal Subjects ◽  
Target Localization ◽  
Whole Body ◽  
Spatial Coding ◽  
Ocular Reflex ◽  
Manual Responses ◽  
Vestibular Cues ◽  
Before And After ◽  
Vestibulo Ocular Reflex

The goal of the present study was to determine if adaptive modulation of vestibulo-ocular reflex (VOR) function is associated with commensurate alterations in manual target localization. To measure the effects of adapted VOR on manual responses we developed the Vestibular-Contingent Pointing Test (VCP). In the VCP test, subjects pointed to a remembered target following passive whole body rotation in the dark. In the first experiment, subjects performed VCP before and after wearing 0.5X minifying lenses that adaptively attenuate horizontal VOR gain. Results showed that adaptive reduction in horizontal VOR gain was accompanied by a commensurate change in VCP performance. In the second experiment, bilaterally labyrinthine deficient (LD) subjects were tested to confirm that vestibular cues were central to the spatial coding of both eye and hand movements during VCP. LD subjects performed significantly worse than normal subjects. These results demonstrate that adaptive change in VOR can lead to alterations in manual target localization.

Estrogen effects on lymph flow as a function of outflow pressure in ewes

1990 ◽  
Vol 258 (5) ◽  
pp. H1317-H1320 ◽  
Author(s):  
G. J. Valenzuela ◽  
S. Kim
Keyword(s):  
Heart Rate ◽  
Flow Rate ◽  
Venous Pressure ◽  
Control Period ◽  
Lymph Flow ◽  
Thoracic Duct Lymph ◽  
Acute Administration ◽  
Before And After ◽  
Estrogen Effects ◽  
Estrogen Administration

The purpose of the present study was to assess whether acute estrogen administration decreased the lymphatic vessel's "pumping" ability. An additional goal was to assess whether estrogen affected the capillary filtration (used here as the total transfer of fluid and protein across the capillaries evidenced by the thoracic duct lymph flow rate). We reasoned that if estrogen administration decreases the lymph pumping ability against outflow pressure, then this phenomenon could help to explain the interstitial fluid retention seen during chronic estrogen. In six nonpregnant ewes we studied the thoracic lymph flow rate measured at different outflow pressures, before and after the acute administration of 50 mg of Premarin (conjugated estrogenic hormones). We also continuously determined arterial and venous pressures and heart rate. The arterial pressure declined from a mean of 99 +/- 0.33 (SE) mmHg to 95.4 +/- 0.2 mmHg (P less than 0.05) after the administration of estrogen. Heart rate increased from 88.5 +/- 0.8 to 111.3 +/- 1.2 beats/min (P less than 0.01). Venous pressure, plasma and lymph protein concentrations, and hematocrit did not change significantly (P greater than 0.1). Lymph flow rate declined progressively when measured against positive outflow pressure, whereas it remained stable when measured against negative pressure. Lymph flow rate during negative outflow pressure was higher after the administration of estrogen 0.044 +/- 0.002 vs. 0.032 +/- 0.002 ml.min-1.kg-1 for the control period (P less than 0.05). The calculated outflow pressure at which lymph flow rate became zero was similar for the period before or after the estrogen administration (P greater than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

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