SECRETION OF ALDOSTERONE IN THE MONOTREME MAMMAL, TACHYGLOSSUS ACULEATUS

1981 ◽  
Vol 90 (2) ◽  
pp. 267-273
Author(s):  
CONRAD SERNIA ◽  
I. R. McDONALD
Keyword(s):  
Angiotensin Ii ◽  
Venous Blood ◽  
Metabolic Clearance ◽  
Control Mechanisms ◽  
Constant Rate ◽  
Response To Stress ◽  
The Mean ◽  
Layer Chromatography ◽  
Mean Concentration ◽  
Rate Infusion

The secretion of aldosterone and its regulation by ACTH and angiotensin II were investigated in conscious, unrestrained echidnas with chronically implanted jugular catheters. Aldosterone was measured by radioimmunoassay after extraction and isolation by silica gel thin-layer chromatography. The mean concentration of aldosterone in blood plasma of five male and three female echidnas was only 5·4 ± 1·3 (s.e.m.) pg/ml. During stress (surgery and anaesthesia) the mean concentration increased to 17·6 ± 3·8 pg/ml. Infusion of β1–24 ACTH at a rate of 5 units/kg per h increased the plasma concentration of aldosterone to 53·8± 9·8 pg/ml. Infusion of angiotensin II at rates of 100 and 500 ng/kg per h also increased aldosterone concentration, to 24·1 ± 8·6 and 35·1 ± 10·9 pg/ml respectively. Production and metabolic clearance rates were measured by the constant-rate infusion of [3H]aldosterone and found to be 5·0 ± 2·2 ng/kg per h and 14·3 ±1·3 ml/kg per min respectively in the unstimulated state. Production rate was increased approximately sevenfold by the infusion of ACTH at 5 units/kg per h and fourfold and sixfold by infusion of angiotensin II at 100 and 500 ng/kg per h respectively. Metabolic clearance decreased following the infusion of ACTH or angiotensin II. Direct measurement of secretion rate by the collection of adrenal venous blood from three anaesthetized, laparotomized echidnas gave values of 9·4, 15·6 and 8·8 mg/kg per h. It is concluded that the adrenal secretion of aldosterone in the echidna is extremely low compared with that in other mammals but the response to stress, ACTH and angiotensin II indicates the presence of typical mammalian control mechanisms for its secretion.

Pharmacokinetics and organ metabolism of carboxyamidated and glycine-extended gastrins in pigs

1996 ◽  
Vol 271 (1) ◽  
pp. G156-G163 ◽  
Author(s):  
C. P. Hansen ◽  
F. Stadil ◽  
L. Yucun ◽  
J. F. Rehfeld
Keyword(s):  
Clearance Rate ◽  
Apparent Volume ◽  
Volume Of Distribution ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Constant Rate Infusion ◽  
Constant Rate ◽  
Vascular Beds ◽  
Apparent Volume Of Distribution ◽  
Rate Infusion

The elimination of carboxyamidated gastrin-17 and its glycine-extended precursor was studied in anesthetized pigs during constant-rate infusion. Extraction of amidated gastrin-17 was recorded in the hindlimb (42%), kidney (40%), head (32%, P < 0.001), and the gut (13%, P < 0.01). Elimination was not recorded in the liver, lungs, or heart. Extraction of glycine-extended gastrin-17 was measured in the kidney (36%), hindlimb (31%, P < 0.001), head (26%), and the gut (16%, P < 0.01), but not in the liver or the lungs. Glycine-extended gastrin-17 was not processed to amidated gastrin during infusion. The half-life, metabolic clearance rate, and apparent volume of distribution for amidated gastrin-17 were 3.5 +/- 0.4 min, 15.5 +/- 1.1 ml.kg-1.min-1, and 76.5 +/- 9.9 ml/kg, respectively, and for glycine-extended gastrin-17 were 4.3 +/- 0.6 min, 17.4 +/- 0.9 ml.kg-1.min-1, and 104.7 +/- 11.9 ml/kg, respectively. We conclude that extraction of amidated and glycine-extended gastrin-17 varies in the vascular beds, with elimination mainly confined to nonorgan tissues and the kidneys.

Binding of 63Ni(II) to Ultrafiltrable Constituents of Rabbit Serum In Vivo and In Vitro

1975 ◽  
Vol 21 (4) ◽  
pp. 521-527 ◽  
Author(s):  
Noritake Asato ◽  
Maria van Soestbergen ◽  
F William Sunderman
Keyword(s):  
Rabbit Serum ◽  
Total Serum ◽  
In Vivo Experiments ◽  
The Mean ◽  
Layer Chromatography ◽  
In Vivo Administration ◽  
Mean Concentration

Abstract Binding of 63Ni(Il) to ultrafiltrable constituents of rabbit serum was studied (a) after in vitro incubation (2 h, 37 °C) of rabbit serum with 63NiCl2 (10-100 µmol/liter), and (b) at intervals (0.25-2 h) after in vivo administration of 63NiCl2 (40-160 µmol/kg body wt, i.v.). Serum ultrafiltrates were fractionated by thin-layer chromatography, and the separated compounds made visible by autoradiography and by ninhydrin staining. Several (≃5) ultrafiltrable 63Ni-complexes were demonstrable as distinct radiodense 63Ni-bands with chromatographic mobilities corresponding to those of ninhydrin-positive bands. Unbound 63Ni(II) was not detected in serum ultrafiltrates in either the in vitro or in vivo experiments. In sera (n = 10) incubated in vitro with 63Ni(II) (10 µmol/ liter), the mean percentage of ultrafiltrable 63Ni was 36% (range = 33-38) of total serum 63Ni. In contrast, in sera (n = 10) obtained 2 h after i.v. injection of 63Ni(II) (40 µmol/kg), the mean concentration of total serum 63Ni was 10.8 µmol/liter (range = 6-14), and the mean percentage of ultrafiltrable 63Ni was 15% (range = 9-21) of total serum 63Ni. The disparity between the percentages of ultrafiltrable 63Ni obtained in vitro and in vivo was obviated when the in vivo experiments were performed in rabbits bilaterally nephrectomized, with ligated common bile ducts. This investigation confirms the existence of several nickel receptors in serum ultrafiltrates and substantiates the role of ultrafiltrable complexes in the excretion of nickel.

scholarly journals The irreversible loss of alanine and of glycine in fetal and sucking lambs

1984 ◽  
Vol 52 (3) ◽  
pp. 529-543 ◽  
Author(s):  
G. M. Hatfield ◽  
Jenny Joyce ◽  
Marjorie K. Jeacock ◽  
D. A. L. Shepherd
Keyword(s):  
Specific Activity ◽  
Single Injection ◽  
Venous Blood ◽  
Injection Technique ◽  
Irreversible Loss ◽  
Fetal Tissues ◽  
Arterial Blood ◽  
Pool Model ◽  
The Mean ◽  
Mean Concentration

1. Estimates have been made of the irreversible loss of alanine and of glycine in chronically catheterized fetal lambs and in sucking lambs using [U-14C]-labelled radioisotopes. The experiments in the fetal lambs were carried out at least 5 d after implantation of catheters.2. The mean concentration of glycine in fetal femoral arterial blood between 102 and 129 d conceptual age was 755 μmol/l and this was not significantly different from that in maternal venous blood. The mean concentration of alanine in fetal femoral arterial blood during the same period of gestation was 229μmol/l and this was significantly greater than that in maternal venous blood.3. Assuming a catenary model, the mean irreversible loss of glycine, determined using the single-injection technique, in three fetal lambs of 107, 111 and 127 d conceptual age was 17 μmol/min per kg, whereas in two fetal lambs aged 106 and 109 d into which the isotope was infused continuously the mean irreversible loss, calculated from the specific activity of glycine 5 h after the start of infusion of the tracer ('pseudo plateau'), was 12 μmol/min per kg. In a sucking lamb, 9 d after birth, the irreversible loss of glycine was 11 μmol/min per kg. The mean irreversible loss of alanine, determined by the single-injection technique assuming a catenary model in five fetuses between 112 and 121 d conceptual age was 14μmol/min per kg, and in two sucking lambs, 9 and 11 d after birth, it was 5.1 μmol/min per kg.4. When a two-pool model was assumed in which entry of metabolite was not directly into the sampling pool but was by way of the second pool, then the mean irreversible loss of glycine in the three fetuses was 23 μmol/min per kg and of alanine in the five fetuses was 32 μmol/min per kg. Calculations based on the alternative two-pool model did not alter appreciably the rates of irreversible loss of either alanine or glycine in the sucking lambs.5. From a comparison of the specific activities of the amino acids and of carbon dioxide in blood during the course of the experiments, it was found that in the fetuses 0.96% of the CO2 present in blood was derived from alanine and only 0.12% was derived from glycine. It was calculated that not more than 1.6 μmol lanine/min per kg and 0.29 μmol glycine/min per kg could have been converted to CO2 in the fetal lambs.6. It is concluded that since glycine in fetal blood originates from fetal tissues and not from direct transfer across the placenta the upper value for the irreversible loss describes metabolism best. In the case of alanine, which is derived from both the maternal circulation and from metabolism in fetal tissues, the true rate of irreversible loss must lie between the values predicted by the two models.

Collaborative Study of a Fluorometric and Thin Layer Chromatographic Determination of Aminacrine and Its Salts in Drug Preparations

1967 ◽  
Vol 50 (3) ◽  
pp. 680-682
Author(s):  
Laura A Roberts
Keyword(s):  
Standard Deviation ◽  
Thin Layer ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Assay Method ◽  
The Mean ◽  
Layer Chromatography ◽  
Mean Concentration

Abstract Eight collaborators studied a fluoromelric and thin layer chromatographic method for aminacrine and its salts in powder and cream drug preparations. Recovery of aminacrine.HCI by fluorometer in both preparations averaged 100% for powder and 102% for cream. The mean concentration of aminacrine.HCI found in the powder was 0.108% with a standard deviation of ± 0.001%. The mean concentration of aminacrine found in the cream was 0.191% with a standard deviation of ± 0.003%. Seven of the 8 collaborators successfully used thin layer chromatography to identify the aminacrine in both sample forms supplied. The assay method for aminacrine and its salts in drug preparations is recommended for adoption as official, first action

scholarly journals Comparison of Propofol or Isoflurane Anesthesia Maintenance, Combined with a Fentanyl–Lidocaine–Ketamine Constant-Rate Infusion in Goats Undergoing Abomasotomy

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 492
Author(s):  
Perla I. Velázquez-Delgado ◽  
Eduardo Gutierrez-Blanco ◽  
Felipe de J. Torres-Acosta ◽  
Antonio Ortega-Pacheco ◽  
Armando J. Aguilar-Caballero ◽  
...  
Keyword(s):  
Systolic Arterial Pressure ◽  
Poor Quality ◽  
Intravenous Anesthesia ◽  
Minimal Impact ◽  
Constant Rate ◽  
The Mean ◽  
Recovery From Anesthesia ◽  
End Tidal ◽  
Rate Infusion

This study aimed to compare, first, the anesthetic and cardiopulmonary effects of propofol or isoflurane anesthetic maintenance in goats receiving a fentanyl–lidocaine–ketamine infusion undergoing abomasotomy and, secondly, to compare the quality of the recovery from anesthesia. Two groups were used: propofol (TIVA) and isoflurane (PIVA). Goats were premedicated with fentanyl (10 μg/kg intravenously [IV]), lidocaine (2 mg/kg, IV), and ketamine (1.5 mg/kg, IV). Anesthesia was induced with propofol and maintenance consisted of fentanyl (10 μg/kg/h, IV), lidocaine (50 μg/kg/min, IV), and ketamine (50 μg/kg/min, IV) as constant-rate infusions (CRIs), combined with either CRI of propofol at initial dose of 0.3 mg/kg/min, IV (TIVA), or isoflurane with initial end-tidal (FE’Iso) concentration of 1.2% partial intravenous anesthesia (PIVA). The mean effective propofol dose for maintenance was 0.44 ± 0.07 mg/kg/min, while the mean FE’Iso was 0.81 ± 0.2%. Higher systolic arterial pressure (SAP) values were observed in total intravenous anesthesia (TIVA) during some time points. Recovery was smooth in PIVA, while restlessness, vocalizations, and paddling were observed in TIVA. Both protocols produced a satisfactory quality of anesthesia during surgery, with minimal impact on cardiopulmonary function. Nevertheless, recovery after anesthesia in TIVA might be of poor quality.

TESTOSTERONE IN RETE TESTIS FLUID AND BLOOD OF RAMS AND RATS

1974 ◽  
Vol 62 (3) ◽  
pp. 619-629 ◽  
Author(s):  
T. G. COOPER ◽  
G. M. H. WAITES
Keyword(s):  
Venous Blood ◽  
Rete Testis ◽  
Jugular Veins ◽  
Testosterone Concentration ◽  
Efferent Duct ◽  
Duct Ligation ◽  
Anaesthetized Rats ◽  
Arterial Inflow ◽  
The Mean ◽  
Mean Concentration

SUMMARY Rete testis fluid (RTF) was collected from six conscious Clun Forest rams by cannulation of the efferent ducts, and from anaesthetized rats by cannulation of the rete testis 16–24 h after efferent duct ligation. Testosterone concentration in this fluid was measured by radioimmunoassay and compared with levels in blood collected from the subcapsular testicular artery and veins and spermatic and jugular veins. The testosterone concentration in ram RTF fluctuated from nondetectable (< 100 pg/ml) levels to approximately 20 ng/ml over 1–25 h collection periods. The mean concentration was 8·5 ± 1·2 (s.e.m.). This value was approximately one fifth the mean concentration of testosterone in samples from the testicular veins at the dorsal pole of the testis. Testosterone concentration (ng/ml) in rat RTF collected under sodium pentobarbitone anaesthesia was 26·4 ± 2·7 (18 measurements, 18 rats). A lower value was obtained when ether was the anaesthetic used during efferent duct ligation (ether, 20·3; halothane, 29·9; sodium pentobarbitone, 29·1). The mean concentration of testosterone in the RTF was similar to that in testicular venous blood (29·8 ± 3·9; 27 measurements, 27 rats), although the highest values were obtained after ether anaesthesia (ether, 38·3; halothane, 29·0; sodium pentobarbitone, 21·7). Testosterone concentration in the testicular arterial inflow was similar to that in jugular venous blood in the ram but exceeded carotid arterial levels in the rat. The values reported are used to discuss: the origin and significance of androgens in rete testis fluid, species differences, the effect of anaesthetics and season, and vascular exchange of testosterone in the spermatic cord.

Reference Values of Umbilical Cord and Third-Day Cystatin C Levels for Determining Glomerular Filtration Rates in Newborns

2003 ◽  
Vol 31 (3) ◽  
pp. 231-235 ◽  
Author(s):  
A Bahar ◽  
Y Yilmaz ◽  
S Unver ◽  
I Gocmen ◽  
F Karademir
Keyword(s):  
Umbilical Cord ◽  
Cystatin C ◽  
Reference Values ◽  
Venous Blood ◽  
Serum Cystatin C ◽  
Serum Cystatin ◽  
Peripheral Venous Blood ◽  
The Mean ◽  
Mean Concentration ◽  
Duration Of Gestation

The aim of this study was to determine reference values for serum cystatin C at, and 3 days after, birth, and to determine if the concentration was influenced by gender, gestational age or bilirubin level. Umbilical cord and peripheral venous blood was taken, and serum cystatin C, creatinine, and total and direct bilirubin levels were measured. The mean concentration of cystatin C was not significantly different between cord blood and blood taken on day 3 (1.36 ± 0.35 mg/l and 1.35 ± 0.33mg/l, respectively). Comparison of subgroups, divided by gender, duration of gestation and bilirubin levels, using the Mann-Whitney U-test and Wilcoxon analysis, showed no effect of these parameters on cystatin C levels.

THE KINETICS OF OESTRADIOL-17β METABOLISM IN THE SHEEP

1973 ◽  
Vol 57 (1) ◽  
pp. 97-110 ◽  
Author(s):  
J. R. G. CHALLIS ◽  
F. A. HARRISON ◽  
R. B. HEAP
Keyword(s):  
Steady State ◽  
Whole Blood ◽  
Clearance Rate ◽  
Venous Blood ◽  
Conversion Ratio ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Tracer Kinetic ◽  
The Mean ◽  
Kinetics Of

SUMMARY The metabolic clearance rate of oestradiol-17β from whole blood and its conversion to oestrone and oestradiol-17α were measured in pregnant and non-pregnant (cyclic, lactating and anoestrous) sheep using tracer kinetic techniques. The metabolic clearance rate was much the same in sheep in different reproductive states (mean in all animals (±s.e.m.) = 2·449 ± 0·155 1/min). The highest values were reached on days 143–145 of pregnancy (3·287 ± 0·3351/min). The mean conversion ratio of oestradiol-17β to oestrone was 17·0 ± 2·2%, and that of oestradiol-17β to oestradiol-17α was 14·1 ± 1·1%. The production rate of oestradiol-17β increased from 0·007 to 0·103 μg/min up to 3 days before parturition to 0·035–1·257 μg/min during the last 12 h of pregnancy. During the continuous infusion of [3H]oestradiol-17β and when a steady state had been reached, approximately 20–30% of the radioactivity in whole blood could be extracted with ether. Of this radioactivity more than 90% was attributable to labelled oestradiol-17β, oestrone and oestradiol-17α in jugular blood, though only about 70% could be accounted for as these oestrogens in uterine venous blood.

Instant 99mTc-Labelled Glucoheptonate Kit for Kidney Imaging

1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha
Keyword(s):  
Sodium Hydroxide Solution ◽  
Normal Subjects ◽  
Organ Distribution ◽  
Stable Complex ◽  
Scintillation Camera ◽  
Ph Adjustment ◽  
The Mean ◽  
The Stability ◽  
Kidney Imaging ◽  
Mean Concentration

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.

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