The nature of the regulatory influences exerted by the hypothalamus on the anterior lobe and pars intermedia of the hypophysis

1964 ◽  
Vol 55 (2) ◽  
pp. 207-210 ◽  
Author(s):  
A. A. Voitkevich ◽  
G. A. Ovchinnikova
Keyword(s):  
Anterior Lobe ◽  
Pars Intermedia

Ultrastructural investigation of an adenoma of the pituitary post mortem

1987 ◽  
Vol 45 ◽  
pp. 622-623
Author(s):  
Shirley Siew ◽  
W. C. deMendonca
Keyword(s):  
Deleterious Effect ◽  
Anterior Lobe ◽  
Definitive Diagnosis ◽  
Pars Intermedia ◽  
Post Mortem ◽  
Close Apposition ◽  
Autopsy Material ◽  
Progressive Loss ◽  
Transmission Electron ◽  
Means Of Transmission

The deleterious effect of post mortem degeneration results in a progressive loss of ultrastructural detail. This had led to reluctance (if not refusal) to examine autopsy material by means of transmission electron microscopy. Nevertheless, Johannesen has drawn attention to the fact that a sufficient amount of significant features may be preserved in order to enable the establishment of a definitive diagnosis, even on “graveyard” tissue.Routine histopathology of the autopsy organs of a woman of 78 showed the presence of a well circumscribed adenoma in the anterior lobe of the pituitary. The lesion came into close apposition to the pars intermedia. Its architecture was more compact and less vascular than that of the anterior lobe. However, there was some grouping of the cells in relation to blood vessels. The cells tended to be smaller, with a higher nucleocytoplasmic ratio. The cytoplasm showed a paucity of granules. In some of the cells, it was eosinophilic.

Somatotopic studies on red nucleus: spinal projection level and respective receptive fields

1975 ◽  
Vol 38 (4) ◽  
pp. 965-980 ◽  
Author(s):  
J. C. Eccles ◽  
T. Rantucci ◽  
P. Scheid ◽  
H. Taborikova
Keyword(s):  
Spinal Cord ◽  
Red Nucleus ◽  
Receptive Fields ◽  
Anterior Lobe ◽  
Cervical Cord ◽  
Pars Intermedia ◽  
Interpositus Nucleus ◽  
Rubrospinal Tract ◽  
Testing Procedures ◽  
Axonal Projections

The somatotopic inputs into red nucleus (RN) neurons have been studied with special reference to their level of projection in the spinal cord. As inputs we employed either volleys in predominantly cutaneous nerves of forelimb and hindlimb or cutaneous mechanoreceptor discharges evoked by taps to footpads of forelimb and hindlimb. There has been physiological confirmation of the anatomical findings that RD neurons projecting to the lumbar cord are located in the ventrolateral zone of the pars magnocellularis, whereas in the dorsomedial zone are RN neurons with cervical but not lumbar projection. Somatotopically there was found to be a differentiation of input to RN neurons according as they projected to the lumbar or only to the cervical cord. This finding was presented in the form both of tables and of somatotopic maps. As expected, this discrimination was more restrictive for the more selective inputs from pad taps than for nerve inputs. Nevertheless, forelimb inputs often had a considerable excitatory and inhibitory action on lumbar-projecting RN neurons, and vice versa for cervical-projecting neurons. There were two notable somatotopic findings that suggest specificities of connectivities. First, despite the large convergence of IP neurons onto RN neurons (about 50-fold), the degree of somatotopic discrimination was about the same for interpositus and RN neurons with two testing procedures: between inputs from forelimb and hindlimb; and between inputs from pads on one foot. Second, although there was in the interpositus nucleus a considerable topographical admixture of neurons with dominant forelimb or hindlimb inputs, the axonal projections of these neurons were apparently unscrambled on the way to the target RN neurons, so as to deliver the somatotopic specificities observed for two classes of RN neurons; those projecting down the spinal cord beyond L2 level, and those projecting to C2 but not L2. Finally, there is a general discussion of motor control with reference to the pathway; pars intermedia of anterior lobe of cerebellum leads to interpositus nucleus leads to red nucleus leads to rubrospinal tract leads to spinal motoneurons.

scholarly journals Expression of 3 beta-hydroxysteroid dehydrogenase/isomerase in the female rat pituitary

2000 ◽  
Vol 166 (1) ◽  
pp. 95-101 ◽  
Author(s):  
S Vidal ◽  
A Roman ◽  
L Moya ◽  
K Kovacs
Keyword(s):  
Present Report ◽  
Hydroxysteroid Dehydrogenase ◽  
Anterior Lobe ◽  
Female Rats ◽  
Endocrine Function ◽  
Pars Intermedia ◽  
Posterior Lobe ◽  
Female Rat ◽  
Target Organs ◽  
Almost All

3 beta-Hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) catalyses an essential step in the biosynthesis of steroid hormones and is widely distributed in peripheral steroid target organs. The present report describes for first time the expression of this enzyme in the pituitary of female rats. Immunohistochemistry at the light microscopic level was performed on pro-oestrous and ovariectomized rat pituitaries. Immunoreactive cells were scattered and randomly distributed throughout the anterior lobe, whereas cells located in the posterior lobe and pars intermedia were immunonegative. Differences were observed in cell morphology and in the number of 3 beta-HSD-immunopositive cells between ovariectomized and pro-oestrous female rat pituitaries, suggesting that steroidogenic activity is affected by ovarian endocrine function. Apart from adenohypophyseal immunoreactive cells, 3 beta-HSD immunopositivity was also noted in endothelial cells of almost all pituitary capillaries located in the anterior and posterior lobes.

scholarly journals EXPERIMENTAL STUDIES ON THE RELATION OF THE PITUITARY BODY TO RENAL FUNCTION

1917 ◽  
Vol 25 (1) ◽  
pp. 153-188 ◽  
Author(s):  
Ketil Motzfeldt
Keyword(s):  
Experimental Studies ◽  
Anterior Lobe ◽  
Renal Nerves ◽  
Initial Increase ◽  
Pars Intermedia ◽  
Corpora Lutea ◽  
Posterior Lobe ◽  
Standard Curve ◽  
Antidiuretic Effect ◽  
Small Doses

1. The inconstant results of past observations on the relation of pituitary extracts to renal activity have been due chiefly to unsuitable methods. 2. A standard curve of artificially induced polyuria may be plotted for rabbits, giving 200 cc. of water by mouth. 3. Extracts of the pars intermedia and posterior lobe of the hypophysis, given by mouth, subcutaneously, or intravenously, are able definitely to check polyuria thus induced. Extracts of the anterior lobe show a similar effect, but only to a slight degree. 4. This antidiuretic effect is constant, and is independent of (a) changes in blood pressure, (b) intestinal absorption, and (c) the vagi. The effect is apparently prevented or delayed by division of the splanchnics, and is diminished by division of the renal nerves near the hilus. 5. A similar antidiuretic property is possessed: (a) by ß-imidazolylethylamine, (b) by p-oxyphenylethylamine, (c) by a preparation from Secale cornutum, (d) by small doses of nicotine, (e) by large doses of caffeine, and (f) by extracts of the adrenal cortex. 6. No effect on the polyuria is produced: (a) by strychnine (b) by morphine, (c) by adrenalin, or by extracts of (d) thyroid, (e) thymus, (f) pineal, (g) pancreas, or (h) corpora lutea. 7. In animals under chloral or paraldehyde anesthesia a short and inconstant initial increase in flow of urine is seen. 8. The antidiuretic effect is absent or only slightly marked in checking the so called salt diuresis.

AUFTRETEN VON KASTRATIONSZELLEN IM HYPOPHYSENVORDERLAPPEN MÄNNLICHER RATTEN NACH BEHANDLUNG MIT EINEM ANTIANDROGEN

1966 ◽  
Vol 53 (1) ◽  
pp. 53-60 ◽  
Author(s):  
F. Neumann
Keyword(s):  
Pituitary Gland ◽  
Inhibitory Effect ◽  
Anterior Lobe ◽  
Male Rats ◽  
Hormone Deficiency ◽  
Pars Intermedia ◽  
Sexual Hormone ◽  
Releasing Factors

ABSTRACT Following the administration of an androgen-antagonist (1,2α-methylene-6-chloro-pregna-4,6-diene-17α-ol-3,20-dione = cyproterone) to male rats, changes are observed in the anterior lobe of the pituitary gland comparable to those which develop following removal of the gonads. The appearance of so called castration cells is very striking, particularly in the periphery, and in the area adjacent to the pars intermedia. The findings suggest that the androgen-antagonism of cyproterone also manifests itself in those receptors of the sex centre, which regulate the amount of gonadotrophin production and secretion in relation to the production of testosterone. Since endogenous testosterone can no longer exert its inhibitory effect on the sex centre, the sex centre, as in a state of sexual hormone deficiency, reacts by secreting releasing factors for gonadotrophins. Thus those cell elements in the anterior lobe of the pituitary gland are stimulated and this leads to the production of gonadotrophin.

Neurointermediate lobe transplanted under the kidney capsule modifies the activity of the neurointermediate lobe in situ, but does not respond to opiate treatment

1986 ◽  
Vol 64 (4) ◽  
pp. 430-437 ◽  
Author(s):  
Christina Gianoulakis ◽  
Alka Gupta
Keyword(s):  
Pituitary Gland ◽  
Direct Effect ◽  
Anterior Lobe ◽  
Pars Intermedia ◽  
Morphine Treatment ◽  
Kidney Capsule ◽  
Neurointermediate Lobe ◽  
Elevated Content ◽  
Naloxone Treatment

To investigate the possibility of a direct effect of morphine on the pars intermedia cells of the pituitary gland, rat neurointermediate lobes (NIL) were transplanted under the kidney capsule. At 2 and 8 days posttransplantation the NIL transplant had maintained its morphological integrity. However, at 15 days posttransplantation the morphological integrity of the NIL transplant had started to deteriorate. The NIL transplant contained, synthesized, and released β-endorphin-like peptides. It was noticed that there was very little β-endorphin in the radiolabelled biosynthesized products, suggesting that either the maturation processing of proopiomelanocortin was modified, or that β-endorphin was released immediately as soon as it was formed and did not accumulate in the tissue. In support of the latter possibility was the elevated content of β-endorphin-like immunoreactivity in the sera of rats with a NIL under the kidney capsule. Furthermore, the NIL transplant seemed to produce a substance or substances which could decrease the content, the biosynthesis and the release of β-endorphin-like peptides by the NIL in situ. Treatment with either morphine or naloxone for 5 days did not change the β-endorphin-like immunoreactivity content in the NIL transplanted under the kidney capsule. However, a distinct decrease in the β-endorphin-like immunoreactivity in the NIL in situ of animals with or without a NIL transplant was observed following the morphine treatment. Naloxone treatment induced a decrease in the β-endorphin-like immunoreactivity content in the hypothalamus, but had no effect on the β-endorphin-like immunoreactivity content in the anterior lobe and NIL of the pituitary gland in situ or in the NIL transplant.

Demonstration of desacetyl α-melanocyte-stimulating hormone in fetal and adult human anterior pituitary corticotrophs

1989 ◽  
Vol 120 (3) ◽  
pp. 525-NP ◽  
Author(s):  
P. J. Coates ◽  
I. Doniach ◽  
J. M. P. Holly ◽  
L. H. Rees
Keyword(s):  
Pituitary Gland ◽  
High Performance ◽  
Anterior Lobe ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Melanocyte Stimulating Hormone ◽  
Pars Anterior ◽  
Human Anterior Pituitary

ABSTRACT Immunocytochemistry, radioimmunoassay and high-performance liquid chromatography (HPLC) techniques have been used in combination to investigate the presence of immunoreactive (ir)-α-MSH in the normal human pituitary gland, and to investigate the possible origin of these cells from the fetal pars intermedia. Two separate antisera to α-MSH were employed in immunocytochemistry to distinguish between authentic α-MSH and the desacetyl form. Only desacetyl α-MSH was detected in the pituitary gland of fetal and adult man, in both the pars (zona) intermedia and the pars anterior. In the fetus, a large proportion of the ACTH-containing cells of the anterior lobe also contained ir-α-MSH, while ir-α-MSH containing cells were more sparse in adults. Radioimmunoassay of acid extracts of adult pituitary tissue showed α-MSH levels representing less than 0·05% of the ACTH content of the gland. HPLC analysis of these extracts confirmed that only the desacetyl form was present. These results suggest that α-MSH peptides are synthesized by anterior lobe cells of the human pituitary gland, which are not derived from the fetal pars intermedia. Possible regulatory mechanisms affecting cells which contain ir-α-MSH are discussed, and by comparison with the intermediate lobe of other species it is concluded that there is little evidence for a true intermediate lobe in the human pituitary gland. Journal of Endocrinology (1989) 120, 525–530

VASCULARITY OF THE HYPOPHYSIS OF LOWER VERTEBRATES: THE PAINTED TURTLE, CHRYSEMYS PICTA MARGINATA AGASSIZ

1952 ◽  
Vol 30 (2) ◽  
pp. 134-143 ◽  
Author(s):  
Stanley James Taylor
Keyword(s):  
Anterior Lobe ◽  
Chrysemys Picta ◽  
Pars Intermedia ◽  
Painted Turtle ◽  
Fresh Tissue ◽  
Vascular Surface ◽  
Lower Vertebrates ◽  
Pars Nervosa ◽  
The Brain ◽  
Adjacent Brain

Measurements were made on the diameter and length of the capillaries of the turtle hypophysis. The volume and surface of vessels were calculated and compared with those of the cat, frog, and salamander. Only the anterior lobe showed vessels which were significantly wider than in the adjacent brain tissue. The surface area of blood in the anterior and tuberal lobes is very extensive, 17 sq. mm. to 18 sq. mm. for 1 cu. mm. of fresh tissue, and is between two and three times as great as in the other lobes and in the richest centers of the brain. The vascular surface in each lobe, except the intermediate one, is lower than, but shows similar variation to, that of the cat. The pars nervosa is supplied by vessels between it and the pars intermedia as in the salamander and is unlike that of the frog or cat with numerous vessels penetrating its substance.

CHANGES IN THE VOLUME OF THE LOBES OF THE PITUITARY GLAND AND IN THE WEIGHT AND WATER CONTENT OF ORGANS OF RATS GIVEN HYPERTONIC SALINE

1968 ◽  
Vol 41 (4) ◽  
pp. 593-600 ◽  
Author(s):  
L. W. DUCHEN
Keyword(s):  
Body Weight ◽  
Sodium Chloride ◽  
Pituitary Gland ◽  
Water Content ◽  
Hypertonic Saline ◽  
Marked Reduction ◽  
Anterior Lobe ◽  
Pars Intermedia ◽  
Posterior Lobe

SUMMARY The volume of the various lobes of the pituitary gland were measured in rats which were given 2% sodium chloride to drink instead of water. The volume of the posterior lobe was increased by 60% after 11 days on saline. The volume of the anterior lobe was slightly decreased but the volume of the pars intermedia was not changed. There was a marked loss of body weight in animals which were given saline and a marked reduction in the weight of the whole pituitary, liver and thyroid.

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