INTERRELATION BETWEEN ADRENAL FUNCTION AND FORMATION OF TESTOSTERONE IN VIVO IN THE TESTIS OF THE DOG

1969 ◽  
Vol 61 (1) ◽  
pp. 33-47 ◽  
Author(s):  
G. F. Wassermann ◽  
K. B. Eik-Nes

ABSTRACT When testes of normal, anaesthetized dogs were infused with the animal's own adrenal venous blood (oxygenated) via the spermatic artery, the secretion of testosterone was higher than by testes infused with the animal's own peripheral, arterial blood. This augmentation in testosterone secretion is probably due to increased biosynthesis of testosterone since the tissue concentration of the hormone at the end of infusion was highest in testes infused with adrenal venous blood. The canine adrenal gland secretes large amounts of progesterone and androst-4-enedione. A minute secretion of free dehydroepiandrosterone can be measured in adrenal venous blood, but no evidence was obtained that the dog adrenal secretes testosterone. The adrenal venous blood of the dog appears to contain a precursor for dehydroepiandrosterone, since testes infused with adrenal venous blood secreted more dehydroepiandrosterone than testes infused with femoral arterial blood. The gonad of the male dog does not secrete progesterone, but secretes free dehydroepiandrosterone, androst-4-enedione and testosterone, the latter compound being the major hormonal product of this tissue. The data have been discussed with regard to a possible adrenal-testicular interaction in the male dog.

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3827
Author(s):  
Gemma Urbanos ◽  
Alberto Martín ◽  
Guillermo Vázquez ◽  
Marta Villanueva ◽  
Manuel Villa ◽  
...  

Hyperspectral imaging techniques (HSI) do not require contact with patients and are non-ionizing as well as non-invasive. As a consequence, they have been extensively applied in the medical field. HSI is being combined with machine learning (ML) processes to obtain models to assist in diagnosis. In particular, the combination of these techniques has proven to be a reliable aid in the differentiation of healthy and tumor tissue during brain tumor surgery. ML algorithms such as support vector machine (SVM), random forest (RF) and convolutional neural networks (CNN) are used to make predictions and provide in-vivo visualizations that may assist neurosurgeons in being more precise, hence reducing damages to healthy tissue. In this work, thirteen in-vivo hyperspectral images from twelve different patients with high-grade gliomas (grade III and IV) have been selected to train SVM, RF and CNN classifiers. Five different classes have been defined during the experiments: healthy tissue, tumor, venous blood vessel, arterial blood vessel and dura mater. Overall accuracy (OACC) results vary from 60% to 95% depending on the training conditions. Finally, as far as the contribution of each band to the OACC is concerned, the results obtained in this work are 3.81 times greater than those reported in the literature.


1992 ◽  
Vol 169 (1) ◽  
pp. 105-119
Author(s):  
B. L. TUFTS ◽  
B. BAGATTO ◽  
B. CAMERON

Exercise in sea lampreys resulted in a significant decrease in the extracellular pH (pHe) in both arterial and venous blood. At rest, the erythrocyte pH (pHi) of venous blood was significantly greater than the pHi of arterial blood. Despite the considerable extracellular acidosis after exercise, both arterial and venous pHi were maintained throughout the recovery period. In the venous blood, there was a reversal of the pH gradient (ΔpH) across the erythrocyte membrane immediately after exercise. Exercise also resulted in significant reductions in the partial pressure of oxygen and hemoglobin oxygen-carriage and a significant increase in the partial pressure of CO2 in arterial and venous blood. Although the total CO2 concentration of the plasma decreased after exercise, erythrocyte total CO2 concentrations (CCOCO2,i) increased. In venous blood, the CCOCO2,i immediately after exercise was double the resting value. At rest, partitioning of the total CO2 content between plasma and erythrocytes indicated that 16 % and 22 % of the total CO2 could be attributed to the erythrocytes in arterial and venous whole blood, respectively. After exercise, these percentages increased to 25% (arterial) and 38% (venous). Changes in CCOCO2,i accounted for 62% of the arteriovenous difference in whole-blood total CO2 at rest. This increased to 78% immediately after exercise. Thus, unlike other vertebrates, CO2 transport in the lamprey in vivo is largely dependent on erythrocyte CO2-carriage.


1998 ◽  
Vol 275 (2) ◽  
pp. R357-R362 ◽  
Author(s):  
Kirsten R. Poore ◽  
I. Ross Young ◽  
Benedict J. Canny ◽  
Geoffrey D. Thorburn

Maturation of the fetal adrenal gland is critical for the onset of ovine parturition. It has long been proposed that the fetal adrenal gland may be under inhibitory influences during late gestation. In vitro evidence has suggested that angiotensin II may be such an inhibitory factor and may help to prevent a premature increase in cortisol concentrations. The aim of this study was to test the effect of angiotensin II infusion in vivo on basal cortisol concentrations and fetal adrenal responsiveness to an ACTH-(1—24) challenge. Fetuses received a continuous infusion of either angiotensin II (100 ng ⋅ min−1 ⋅ kg−1; n = 7) or saline (2 ml/h; n = 4), which commenced at 140 days of gestation (GA) and continued for a total of 50 h. Adrenal responsiveness to the administration of ACTH-(1—24) (5 μg/kg) was determined during angiotensin II or saline infusions at both 2 and 48 h after infusion onset. Angiotensin II had no significant effect on adrenal responsiveness after acute (2 h) or chronic (48 h) infusion. There was no effect of saline or angiotensin II infusion on basal immunoreactive ACTH or cortisol concentrations after 2 h, but there was a significant increase in basal cortisol concentrations in both treatment groups by 48 h, probably reflecting the normal rise in cortisol concentrations at this GA. Mean arterial blood pressure was significantly increased in angiotensin II-infused fetuses only. This study has therefore found no evidence to suggest that angiotensin II infusion in vivo modulates fetal basal cortisol concentrations or adrenal responsiveness in the last week of gestation, in contrast with previous in vitro studies. These results throw into question the proposed role of angiotensin II as a negative modulator of adrenal function in the ovine fetus.


2011 ◽  
Vol 4 ◽  
pp. JCD.S6444 ◽  
Author(s):  
Jessica F. White ◽  
Andrew S. Cowburn ◽  
Charlotte Summers ◽  
Karen A. Cadwallader ◽  
Iain Mackenzie ◽  
...  

In contrast to radiolabelled erythrocytes and platelets, radiolabelled neutrophils leave the circulating blood in an exponential manner, indicating random rather than age-dependent removal. Neutrophils transit the spleen with a range of residence times that are log normally distributed. We hypothesized that neutrophils are conditioned to undergo apoptosis to an extent that depends on their intrasplenic residence time and that this provides an explanation for the random removal of these cells from blood. Splenic venous and peripheral arterial blood was sampled simultaneously during abdominal surgery in four patients and age-dependent apoptosis assessed in whole blood using annexin V/PI staining. Apoptosis increased after 4 and 20 h ex-vivo incubation and was invariably higher in splenic venous vs arterial neutrophils. Transit through the spleen appears to promote neutrophil apoptosis, with subsequent high efficiency clearance by the liver. This may explain the mechanism underlying the random removal of neutrophils from the blood.


1994 ◽  
Vol 266 (5) ◽  
pp. C1400-C1405 ◽  
Author(s):  
H. Kosaka ◽  
Y. Sawai ◽  
H. Sakaguchi ◽  
E. Kumura ◽  
N. Harada ◽  
...  

Nitric oxide (NO) generation was induced in rats by Escherichia coli lipopolysaccharide (LPS) as detected by electron spin resonance (ESR) signals of NO hemoglobin (HbNO). However, there were inconsistencies in ESR spectral shape among them. We have therefore carried out a systematic study to clarify the in vivo spectral changes. First, the spectra of the alpha-NO heme species had the distinct three-line hyperfine structure in venous blood but not in arterial blood in all rats treated with tumor necrosis factor, interleukin-1, and/or LPS, and methemoglobin was not detected at the g = 6 (high-spin methemoglobin) region. Second, when the treated rats died, the three-line hyperfine structure was very distinct even in arterial blood. Third, even if HbNO was formed by injection of nitrite to rats, the three-line hyperfine structure of HbNO in venous blood was more marked than that in arterial blood, independent of the appearance of the methemoglobin signal. Fourth, an ex vivo study using whole blood demonstrated that the three-line hyperfine structure intensified lineally when O2 saturation of hemoglobin decreased but disappeared on reoxygenation of hemoglobin. These results directly demonstrate in vivo quaternary structural transition of the hemoglobin tetramer from the high-affinity state in the arterial cycle to the low-affinity state in the venous cycle. The transition makes the diverse ESR spectra of HbNO in vivo.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Dilmurodjon Eshmuminov ◽  
Dustin Becker ◽  
Max L. Hefti ◽  
Matteo Mueller ◽  
Catherine Hagedorn ◽  
...  

AbstractLong-term perfusion of liver grafts outside of the body may enable repair of poor-quality livers that are currently declined for transplantation, mitigating the global shortage of donor livers. In current ex vivo liver perfusion protocols, hyperoxic blood (arterial blood) is commonly delivered in the portal vein (PV). We perfused porcine livers for one week and investigated the effect of and mechanisms behind hyperoxia in the PV on hepatic arterial resistance. Applying PV hyperoxia in porcine livers (n = 5, arterial PV group), we observed an increased need for vasodilator Nitroprussiat (285 ± 162 ml/week) to maintain the reference hepatic artery flow of 0.25 l/min during ex vivo perfusion. With physiologic oxygenation (venous blood) in the PV the need for vasodilator could be reduced to 41 ± 34 ml/week (p = 0.011; n = 5, venous PV group). This phenomenon has not been reported previously, owing to the fact that such experiments are not feasible practically in vivo. We investigated the mechanism of the variation in HA resistance in response to blood oxygen saturation with a focus on the release of vasoactive substances, such as Endothelin 1 (ET-1) and nitric oxide (NO), at the protein and mRNA levels. However, no difference was found between groups for ET-1 and NO release. We propose direct oxygen sensing of endothelial cells and/or increased NO break down rate with hyperoxia as possible explanations for enhanced HA resistance.


1978 ◽  
Vol 77 (3) ◽  
pp. 283-291 ◽  
Author(s):  
J. G. PHILLIPS ◽  
W. POOLSANGUAN

There is a temporal relationship between the secretory activity of the rat adrenal gland and the stage of the oestrous cycle. In previous studies, adrenal venous blood has been sampled, but because of the stress of a lengthy operation, the gland is subjected to maximum stimulation. A new surgical approach has been developed in which samples of adrenal venous blood are taken within 3 min of contact. A competitive binding radioassay was used to determine the level of corticosterone in samples of plasma of both adrenal venous and peripheral arterial origin obtained before (3 min) and after (15 min) the onset of (presumably) ACTH-induced secretion. A reassessment of adrenal function indicated that adrenal activity peaked in pro-oestrus with higher values in the afternoon than the morning and both values were significantly higher than at any other stage in the oestrous cycle. The variations in the concentration of corticosterone in adrenal venous plasma were reflected by a similar pattern of variation in the level of corticosterone in peripheral arterial plasma. In samples of adrenal venous plasma obtained at 15 min, the level of corticosterone was approximately 25 times higher than the basal value during pro-oestrus and approximately 140 times higher than the values during the other stages of the cycle; for peripheral arterial blood the values were eight and 22–30 times higher respectively, without any significant difference when samples of either type of blood were obtained under stress. This indicates maximum stimulation by endogenous ACTH. Results obtained after treatment of ovariectomized rats with progesterone and/or oestradiol and the fact that LH, but not ACTH, plays a stimulatory role in the non-stressed metoestrous animal, suggest that the peak of adrenal activity at the time of pro-oestrus might be biphasic: in the morning it is influenced by a high level of oestrogen and a low level of progesterone; in the afternoon this balance is reversed. The effect is secondary to the surge of LH which may have a direct effect on the peak of adrenal activity at this critical period.


1993 ◽  
Vol 264 (3) ◽  
pp. E413-E419 ◽  
Author(s):  
B. R. Boulanger ◽  
M. P. Lilly ◽  
J. M. Hamlyn ◽  
J. Laredo ◽  
D. Shurtleff ◽  
...  

Ouabain has been identified in the plasma and adrenal glands of several mammals, including humans. To investigate possible adrenal secretion of ouabain in vivo, at rest, and in response to acute blood volume changes, we prepared trained adult dogs (n = 10) with splenectomy and unilateral adrenal venous (AV) cannulation. Two days later, after an overnight fast, dogs had either 1) 20% hemorrhage (hem) or 2) 20% blood volume expansion (exp; 6% Dextran 70, 0.9% NaCl) in random order. In AV and arterial plasma (ART), ouabain was measured by a ouabain-specific immunoassay, and cortisol and aldosterone were measured by radioimmunoassay. ART and AV ouabain concentration did not change after hem or exp [P = not significant (NS)]. In 94 of 97 paired samples, the concentration of ouabain in AV was greater than that in ART (Wilcoxon, P < 0.001), and the mean ouabain concentration was greater in AV (756.4 +/- 85.7 pmol/l) than ART (235.4 +/- 18.5 pmol/l; P < 0.001). The mean AV-to-ART ouabain concentration ratio was 5.7 +/- 1.29. Adrenal secretion of ouabain was not influenced by hem or exp (analysis of variance, P = NS). Adrenal secretion of cortisol and aldosterone increased after hem (P < 0.05) and was unaltered by exp (P = NS). This study demonstrates that ouabain is secreted by the adrenal gland in the awake dog. However, adrenal ouabain secretion and arterial blood ouabain are not altered by acute hem or exp.


1994 ◽  
Vol 79 (5) ◽  
pp. 1492-1497
Author(s):  
J A Gonzalez-Hernandez ◽  
S R Bornstein ◽  
M Ehrhart-Bornstein ◽  
E Späth-Schwalbe ◽  
G Jirikowski ◽  
...  

1974 ◽  
Vol 60 (1) ◽  
pp. 71-83 ◽  
Author(s):  
F. B. EDDY

1. The respiration of tench at 13°C was investigated, particular attention being given to the role of the blood in uptake and transport of oxygen. 2. In well aerated water the mean value for arterial blood was 36 mmHg, for PCOCO2 3.3 mmHg and for pH 8.16; the respective venous values were 7 mmHg, 5 mmHg and 8.08. Arterial blood averaged about 75% and venous blood about 40° oxygen saturation. The mean value for oxygen uptake was 0.5 ml/min/kg and for ventilation volume 132/ml/mm/kg. 3. The oxygen tension and the percentage saturation of the blood determined in vivo are discussed in terms of the oxygen dissociation curve determined in vitro. 4. When the environmental POO2 was decreased, tench responded by increasing breathing rate and ventilation volume. Arterial POO2 and PCOCO2 decreased but arterial pH tended to remain steady. There was also a significant increase in blood lactate. 5. That tenth can withstand severe hypoxic conditions is attributed to blood of high oxygen affinity and the ability to maintain a favourable acid-base status in the blood for oxygen transport. 6. Respiration in tench is compared with that in other fish species.


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