Effects of ACTH on the zona glomerulosa of sodium-loaded timolol maleate-treated rats: stereology and plasma hormone concentrations

1982 ◽  
Vol 99 (2) ◽  
pp. 256-262 ◽  
Author(s):  
Gastone G. Nussdorfer ◽  
Giulano Neri ◽  
Anna S. Belloni ◽  
Giuseppina Mazzocchi ◽  
Piera Rebuffat ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Zona Glomerulosa ◽  
The Other ◽  
Cell Type ◽  
Timolol Maleate ◽  
Aldosterone Secretion ◽  
Sodium Loading ◽  
Plasma Hormone

Abstract. The effect of chronic ACTH administration on the growth and aldosterone secretion of the zona glomerulosa of sodium-loaded timolol maleate-treated rats was investigated by stereological and radioimmunological techniques. Combined sodium loading and timolol maleate administration induced a significant atrophy of the zona glomerulosa and its cells. The plasma concentration of aldosterone was significantly decreased, while that of corticosterone did not vary. ACTH administration completely reversed zona glomerulosa atrophy, and the plasma concentration of corticosterone was noticeably enhanced, whereas that of aldosterone underwent a further decrease. This data suggests that in the absence of the other adrenoglomerulotrophic factors, ACTH stimulates the growth of the zona glomerulosa, but transforms its parenchymal elements to a functional fasciculata cell type.

Physiological attributes as possible selection criteria for milk production 3. Plasma hormone concentrations and metabolite and hormonal responses to changes in energy equilibrium

1983 ◽  
Vol 37 (2) ◽  
pp. 165-178 ◽  
Author(s):  
R. B. Land ◽  
W. R. Carr ◽  
I. C. Hart ◽  
T. J. Osmond ◽  
R. Thompson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Plasma Concentration ◽  
Milk Production ◽  
Selection Criteria ◽  
The Other ◽  
Hormonal Responses ◽  
Energy Equilibrium ◽  
Plasma Hormone ◽  
High Level

ABSTRACTPlasma hormone concentrations and metabolite responses to changes in energy equilibrium were measured in experiments designed to compare a) Hereford × Friesian with Friesian calves and b) Friesian calves sired by bulls with a high level of Improved Contemporary Comparison with those sired by bulls of a low level. The concentration of thyroxine and triiodothyronine tended to be greater in calves of higher dairy merit. The concentration of growth hormone was largely unrelated to dairy merit in the circumstances studied. The concentration of insulin was greater in Hereford × Friesian than in Friesian calves following feeding and following the injection of propionate. Responses to the injection of insulin and of growth hormone (as measured by changes in the plasma concentration of urea nitrogen, free fatty acids, glucose or the other hormone) were little affected by the level of Improved Contemporary Comparison of a calfs sire.It was concluded that the thyroid system and the response of insulin to perturbation of energy balance may provide criteria of genetic merit for milk production which are neither age- nor sex-limited.

Effects of angiotensin II on the zona glomerulosa of sodium-loaded dexamethasone treated rats administered or not with maintenance doses of ACTH: stereology and plasma hormone concentrations

1983 ◽  
Vol 102 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Giuseppina Mazzocchi ◽  
Virgilio Meneghelli ◽  
Gastone G. Nussdorfer
Keyword(s):  
Angiotensin Ii ◽  
Zona Glomerulosa ◽  
Trophic Effects ◽  
Sodium Loading ◽  
Plasma Hormone

Abstract. The trophic effects of angiotensin II on the rat zona glomerulosa were investigated by stereological and radioimmunological methods. Angiotensin II was not able to reverse the sodium-loading and dexamethasone-induced inhibition of the growth and steroidogenic capacity of the zona glomerulosa. However, if the sodium-loaded dexamethasone-treated rats were given maintenance doses of ACTH, angiotensin II exerted a strong adrenoglomerulotrophic effect. The hypothesis is advanced that the co-operation of ACTH and angiotensin II is required in the maintenance of the morphologic and enzymatic integrity of the rat zona glomerulosa.

scholarly journals Role of tyrosine kinase and protein kinase C in the steroidogenic actions of angiotensin II, α-melanocyte-stimulating hormone and corticotropin in the rat adrenal cortex

1995 ◽  
Vol 305 (2) ◽  
pp. 433-438 ◽  
Author(s):  
S Kapas ◽  
A Purbrick ◽  
J P Hinson
Keyword(s):  
Protein Kinase C ◽  
Angiotensin Ii ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Zona Glomerulosa ◽  
Aldosterone Secretion ◽  
Melanocyte Stimulating Hormone ◽  
Kinase C ◽  
Stimulating Hormone

The role of protein kinases in the steroidogenic actions of alpha-melanocyte-stimulating hormone (alpha-MSH), angiotensin II (AngII) and corticotropin (ACTH) in the rat adrenal zona glomerulosa was examined. Ro31-8220, a potent selective inhibitor of protein kinase C (PKC), inhibited both AngII- and alpha-MSH-stimulated aldosterone secretion but had no effect on aldosterone secretion in response to ACTH. The effect of Ro31-8220 on PKC activity was measured in subcellular fractions. Basal PKC activity was higher in cytosol than in membrane or nuclear fractions. Incubation of the zona glomerulosa with either alpha-MSH or AngII resulted in significant increases in PKC activity in the nuclear and cytosolic fractions and decreases in the membrane fraction. These effects were all inhibited by Ro31-8220. ACTH caused a significant increase in nuclear PKC activity only, and this was inhibited by Ro31-8220 without any significant effect on the steroidogenic response to ACTH, suggesting that PKC translocation in response to ACTH may be involved in another aspect of adrenal cellular function. Tyrosine phosphorylation has not previously been considered to be an important component of the response of adrenocortical cells to peptide hormones. Both AngII and alpha-MSH were found to activate tyrosine kinase, but ACTH had no effect, observations that have not been previously reported. Tyrphostin 23, a specific antagonist of tyrosine kinases, inhibited aldosterone secretion in response to AngII and alpha-MSH, but not ACTH. These data confirm the importance of PKC in the adrenocortical response to AngII and alpha-MSH, and, furthermore, indicate that tyrosine kinase may play a critical role in the steroidogenic actions of AngII and alpha-MSH in the rat adrenal zona glomerulosa.

The effect of pancreatic mesenchyme on the differentiation of endocrine cells from gastric endoderm

Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 661-671 ◽  
Author(s):  
B. Kramer ◽  
A. Andrew ◽  
B.B. Rawdon ◽  
P. Becker
Keyword(s):  
Endocrine Cell ◽  
Endocrine Cells ◽  
Cell Types ◽  
The Other ◽  
Chick Embryos ◽  
Cell Type ◽  
Pancreatic Insulin ◽  
Somatostatin Cells ◽  
Regional Specificity ◽  
Gut Endocrine Cells

To determine whether mesenchyme plays a part in the differentiation of gut endocrine cells, proventricular endoderm from 4- to 5-day chick or quail embryos was associated with mesenchyme from the dorsal pancreatic bud of chick embryos of the same age. The combinations were grown on the chorioallantoic membranes of host chick embryos until they reached a total incubation age of 21 days. Proventricular or pancreatic endoderm of the appropriate age and species reassociated with its own mesenchyme provided the controls. Morphogenesis in the experimental grafts corresponded closely to that in proventricular controls, i.e. the pancreatic mesenchyme supported the development of proventricular glands from proventricular endoderm. Insulin, glucagon and somatostatin cells and cells with pancreatic polypeptide-like immunoreactivity differentiated in the pancreatic controls. The latter three endocrine cell types, together with neurotensin and bombesin/gastrin-releasing polypeptide (GRP) cells, developed in proventricular controls and experimental grafts. The proportions of the major types common to proventriculus and pancreas (somatostatin and glucagon cells) were in general similar when experimental grafts were compared with proventricular controls but different when experimental and pancreatic control grafts were compared. Hence pancreatic mesenchyme did not materially affect the proportions of these three cell types in experimental grafts, induced no specific pancreatic (insulin) cell type and allowed the differentiation of the characteristic proventricular endocrine cell types, neurotensin and bombesin/GRP cells. However, an important finding was a significant reduction in the proportion of bombesin/GRP cells, attributable in part to a decrease in their number and in part to an increase in the numbers of endocrine cells of the other types. This indicates that mesenchyme may well play a part in determining the regional specificity of populations of gut endocrine cells.

The retinotectal projections after uncrossing the optic chiasma in Xenopus with one compound eye

Development ◽  
1971 ◽  
Vol 26 (3) ◽  
pp. 523-542
Author(s):  
K. Straznicky ◽  
R. M. Gaze ◽  
M. J. Keating
Keyword(s):  
Compound Eye ◽  
The Other ◽  
Cell Type ◽  
Cell Type Specificity ◽  
Optic Chiasma ◽  
Normal Side ◽  
Cell Specificity ◽  
Normal Projection ◽  
Retinotectal Projections ◽  
Fixed Cell

The nature of the retinotectal projection from a compound (NN or TT) eye in Xenopus raises certain problems concerning the mode of formation of connexions between the eye and the tectum. Each half of the compound eye appears to spread its connexions across the entire extent of the (apparently normal) contralateral tectum. This could indicate a certain plasticity in the way in which optic fibres can connect with the tectum. Alternatively, it is conceivable that each (similar) half of the compound eye is only able to innervate its corresponding half-tectum; in which case the uninnervated half-tectum could remain undeveloped and the innervated half-tectum could overgrow to resemble a normal tectum. This mechanism would preserve the idea of a rigidly fixed cell-to-cell specificity between retina and tectum. In an attempt to distinguish between these two mechanisms (spreading or overgrown half-tectum) we have given each of a series of Xenopus embryos at stage 32 one compound eye (NN or TT). Then, shortly after metamorphosis, we uncrossed the optic chiasma and 6 months later recorded the retinotectal projections from each eye to the tecta. Thus by connecting up the normal eye to the suspect tectum, and the compound eye to the normal tectum, we used the normal side in each case to provide an indication of the degree of abnormality with which the other side was connected. The results showed that a compound eye (NN or TT), connected to a normal tectum, gave a typical reduplicated map across the entire tectum, whereas the normal eye, when connected to the tectum which was previously innervated by the compound eye, gave an approximately normal projection across the whole of that tectum. These results lead us to conclude that, in the Xenopus visual system, no strict cell-to-cell type specificity exists; rather, what is preserved throughout these experimental manoeuvres is the polarity and extent of the projection.

Effects of prolonged dopamine infusion on the zona glomerulosa of sodium-restricted rats treated or not with prolactin: Stereology and plasma hormone concentrations

1988 ◽  
Vol 188 (3) ◽  
pp. 209-216
Author(s):  
P. Rebuffat ◽  
A. S. Belloni ◽  
G. Mazzocchi ◽  
G. Gottardo ◽  
L. K. Malendowicz ◽  
...  
Keyword(s):  
Zona Glomerulosa ◽  
Dopamine Infusion ◽  
Plasma Hormone

scholarly journals Periaqueductal efferents to dopamine and GABA neurons of the VTA

2017 ◽  
Author(s):  
Niels R. Ntamati ◽  
Meaghan Creed ◽  
Christian Lüscher
Keyword(s):  
Functional Analysis ◽  
Ventral Tegmental Area ◽  
Periaqueductal Gray ◽  
Retrograde Tracing ◽  
The Other ◽  
Projection Neurons ◽  
Cell Type ◽  
Gaba Neurons ◽  
Other Hand ◽  
Cell Type Specific

AbstractNeurons in the periaqueductal gray (PAG) modulate threat responses and nociception. Activity in the ventral tegmental area (VTA) on the other hand can cause reinforcement and aversion. While in many situations these behaviors are related, the anatomical substrate of a crosstalk between the PAG and VTA remains poorly understood. Here we describe the anatomical and electrophysiological organization of the VTA-projecting PAG neurons. Using rabies-based, cell type-specific retrograde tracing, we observed that PAG to VTA projection neurons are evenly distributed along the rostro-caudal axis of the PAG, but concentrated in its posterior and ventrolateral segments. Optogenetic projection targeting demonstrated that the PAG-to-VTA pathway is predominantly excitatory and targets similar proportions of Ih-expressing VTA DA and GABA neurons. Taken together, these results set the framework for functional analysis of the interplay between PAG and VTA in the regulation of reward and aversion.

ADRENAL POTASSIUM AND SODIUM IN EXPERIMENTAL HYPER- AND HYPOALDOSTERONISM IN THE RAT. DETERMINATION BY ELECTRON PROBE X-RAY MICROANALYSIS

1975 ◽  
Vol 80 (1) ◽  
pp. 114-125 ◽  
Author(s):  
Katalin Sz. Szalay ◽  
Ernö Bácsy ◽  
Ervin Stark
Keyword(s):  
Electron Probe ◽  
Sodium Content ◽  
Zona Glomerulosa ◽  
Potassium Content ◽  
Zona Fasciculata ◽  
Aldosterone Secretion ◽  
X Ray ◽  
Intracellular Potassium

ABSTRACT Potassium and sodium contents in the various adrenal zones were determined in experimental hyper- and hypoaldosteronism in the rat by electron probe X-ray microanalysis. The analysis aimed at revealing intracellular values. There was no change in the potassium content of the zona glomerulosa, zona fasciculata and medulla neither in hyperaldosteronism, induced by Na-deficiency, nor in hypoaldosteronism, elicited by Na-rich diet. The sodium content in the zona glomerulosa and zona fascicularis was increased in the Na-loaded rats, while that of the medulla was not changed. Our data are not consistent with the hypothesis that a change of adrenal intracellular potassium would act as a final stimulus in the regulation of aldosterone secretion.

scholarly journals Propofol Induction for Laryngeal Mask Airway Insertion: Dose Requirement and Cardiorespiratory Effects

1992 ◽  
Vol 20 (4) ◽  
pp. 479-483 ◽  
Author(s):  
D. W. Blake ◽  
P. Dawson ◽  
G. Donnan ◽  
A. Bjorksten
Keyword(s):  
Plasma Concentration ◽  
Laryngeal Mask Airway ◽  
Cardiovascular Effects ◽  
Laryngeal Mask ◽  
The Other ◽  
Laryngeal Mask Airway Insertion ◽  
Dose Requirement ◽  
Respiratory Effects

The dosage, haemodynamic and respiratory effects of propofol for laryngeal mask airway (LMA) insertion were investigated. Fifty patients (ASA I-II) were randomly assigned one of four induction doses of propofol (1.5–2.5 mg/kg) delivered over 30 seconds and the first attempt at LMA insertion was made at 90 seconds. The LMA was inserted at 90 seconds in 35 patients and by 300 seconds in 13 others (mean plasma concentration at 90 seconds was 7.7 mcg/ml (no delay) versus 5.2 mcg/ml (insertion delayed), P < 0.01). Insertion was less successful after 1.5 mcg/kg (failed at 90 seconds in 6 of 12 patients), but did not vary with the other doses. Additional propofol (0.5 mg/kg/30s) was required in 22 patients for LMA insertion or to prevent movement, resulting in propofol concentrations at 120–180 seconds above 7 mcg/ml. Respiratory effects were minor, but MAP decreased by 18±1.4 mmHg at 90 seconds. Cardiovascular effects did not differ significantly between dosage groups or with the use of additional propofol.

Histochemical localization of enzymes of various metabolic pathways in the testes of buffaloes, goats and rams

1984 ◽  
Vol 102 (2) ◽  
pp. 269-274 ◽  
Author(s):  
G. S. Bilaspuri ◽  
S. S. Guraya
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Metabolic Pathways ◽  
Maximum Activity ◽  
The Other ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Cell Type ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Enzyme Species

SummaryIsocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), β-hydroxybutyrate dehydrogenase (β-OH-BDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) were histochemically located in the testes of buffaloes, goats and rams. The enzyme activities varied with the enzyme, species and cell type. The activities in the seminiferous tubules were correlated with the stages of seminiferous epithelial cycle (SEC). During this cycle, the activities in the Sertoli cells, spermatogonia and spermatocytes remained unaltered in contrast to those in the spermatids. The activities of SDH, ICDH and MDH were relatively greater in buffalo, while goat and ram resembled each other quite closely. ICDH and MDH preferred NADP to NAD. In the three species, the activities of ICDH, SDH and MDH generally followed an increasing order. G-6-PDH was greater in the interstitial tissue of buffalo than in goat and ram; the maximum activity of this enzyme in each species was found in the spermatogonia. In comparison with G-6-PDH, GDH was less evident in the interstitial tissue of buffalo and goat; Sertoli cells and spermatogonia also showed relatively less MDH activity whereas the other germ cells may have relatively less, similar or more, GDH activity depending on the species. β-OHBDH activity was similar in the interstitial tissue of the three species, but in the seminiferous tubule, the activity was less in goat. But for GDH and β-OH-BDH which could show different results, the activities of other enzymes generally decreased from spermatogonia through spermatocytes to spermatids but increased during spermiogenesis. In spermatozoa, the enzymes were observed only in the mid-piece. The possible physiological significance of the results is discussed in relation to different metabolic pathways.

Sign in / Sign up

Export Citation Format

Share Document