Alteration in response of the portal tributary vascular bed to the beta-agonist dobutamine in rats with extrahepatic portal hypertension

The acute effects of 2 doses of the beta-agonist dobutamine on systemic and splanchnic haemodynamics were studied in normal rats and in rats with portal hypertension due to portal vein stenosis. Cardiac output and splanchnic organ blood flow were estimated with the radioactive microsphere method and portal pressure was measured. Low dose (5 micrograms/kg) of dobutamine did not change significantly arterial pressure and portal pressure but, cardiac output was significantly higher after dobutamine than after placebo in both groups of rats. Similar results were observed with 15 micrograms/kg of dobutamine except for a significant decrease in arterial pressure in portal-hypertensive rats. In sham-operated rats, dobutamine significantly increased portal tributary blood flow; this rise was parallel to cardiac output. In contrast, in portal-hypertensive rats, portal tributary blood flow did not change significantly after dobutamine. Accordingly in the former group, portal tributary vascular resistance significantly decreased, whereas in the latter group, no change in this resistance was observed with a low dose and a significant decrease was noted with a high dose. In both groups of rats, hepatic arterial blood flow was not significantly different after dobutamine than after placebo. This study demonstrates that the vasodilatory response of the portal tributary vascular bed to an increase in cardiac output is altered in anaesthetized rats with portal hypertension due to portal vein stenosis.

Circulatory actions of vasopressin in anaesthetized rats with portal hypertension subjected to haemorrhage

To assess the influence of vasopressin on splanchnic and renal circulatory changes induced by haemorrhage in portal hypertension, we studied 4 groups of 7 rats with chronic portal vein stenosis. Two groups received saline (C and H) and two groups vasopressin, 0.01 IU/kg/min (VP and VP-H). Ten minutes after starting drug infusion, group H and VP-H animals were allowed to bleed from the superior mesenteric vein. Both haemorrhage and vasopressin alone, decreased portal venous tributary blood flow and pressure but their association was not additive (as reflected by comparable bleeding rate in groups H and VP-H). By contrast, vasopressin increased renal perfusion in bleeding and non-bleeding animals whereas haemorrhage alone decreased renal perfusion. These results indicate that the effects of vasopressin on the splanchnic circulation in bleeding anaesthetized animals differ from the effects observed when blood volume is normal. Therefore, in patients with cirrhosis the effects of vasopressin during bleeding might also differ from those observed in patients in stable condition.

[Endocrine pancreatic tumor secreting somatostatin and somatocrinin]

A case of endocrine pancreatic tumour secreting the 2 antagonistic peptides that regulate growth hormone, somatostatin and somatocrinin, is reported. Such tumours are extremely rare and only one other case has been published so far, although pancreatic malignant tumours frequently secrete several hormones. In our patient, the association of diabetes with steatorrhoea, hypochlorhydria, anaemia and biliary lithiasis suggested hypersecretion of somatostatin. Acromegaly, suggested by clinical signs, was confirmed by an excess of growth hormone and somatomedin, and pre-operative somatrocrinin assay confirmed its extra-pituitary origin. Finally, the presence of hyperparathyroidism due to parathyroid gland hyperplasia and of a Recklinghausen disease constituted a multiple endocrine neoplasia syndrome. The significance and implications of this double secretion in vivo are discussed.

Effects of pentobarbital sodium anesthesia on splanchnic hemodynamics of normal and portal-hypertensive rats

To determine the effect of pentobarbital sodium anesthesia on the rat with portal hypertension due to portal vein stenosis, four groups of rats were studied. Cardiac output and regional blood flow were measured by radioactive microspheres in anesthetized and conscious sham-operated and portal-hypertensive rats. Anesthesia markedly decreased cardiac output in both sham-operated (109.7 +/- 4.6 vs. 77.8 +/- 1.4 ml/min, P less than 0.001) and portal-hypertensive rats (130.1 +/- 7.6 vs. 93.8 +/- 5.3 ml/min, P less than 0.01). In spite of this diminution in cardiac output, pentobarbital did not significantly change absolute blood flow values of splanchnic organs in either group. However, the fractions of cardiac output perfusing the splanchnic organs were significantly increased by pentobarbital in both groups because of the decrease in cardiac output: sham operated, anesthetized, 22.86 +/- 1.19% vs. conscious, 14.83 +/- 1.02%, P less than 0.001; and portal hypertensive, anesthetized, 26.67 +/- 0.71% vs. conscious, 19.07 +/- 1.44%, P less than 0.001. The hyperdynamic circulation of the portal vein-stenosed rat compared with the sham-operated rat continued to manifest itself with significantly increased portal pressure, cardiac output, and splanchnic blood flow, whether the animal was anesthetized or awake. We conclude that, despite marked hemodynamic changes induced by pentobarbital, the rat with portal vein stenosis remains a useful experimental model of portal hypertension.

Somatotropic adenoma manifested by galactorrhea without acromegaly

In two of eight premenopausal women with somatotropic adenomas, galactorrhea was the earliest clinical feature, associated in one patient with amenorrhea. These two patients did not have clinically evident acromegaly. Mean basal serum GH levels were elevated and did not decrease after glucose ingestion. Both patients had modest hyperprolactinemia. Histological and immunocytological studies of the adenomas showed numerous adenomatous somatotropic cells and some alpha-subunit- and PRL-containing cells. In these patients, the origin of the hyperprolactinemia was not clear. In one patient, elevated GH secretion was probably responsible for the galactorrhea, since it disappeared after surgical treatment despite persistence of hyperprolactinemia. In conclusion, galactorrhea, isolated or associated with amenorrhea, can be the only clinical manifestation of a somatotropic adenoma.

Immunocytochemical localization of S-100 protein in interstitial cells of the monkey Macaca irus pineal gland

Pineal interstitial cells of the monkey Macaca irus were shown to react with an anti-human S-100 protein antibody, using the indirect immunoperoxidase technique on sections of paraplast-embedded pineal glands. Immunoreactivity was seen in the cytoplasm of the cells, stellate in shape and intermingled with pinealocytes; the latter did not stain with the antiserum against S-100 protein. Immunoreactivity was also present in the nuclei, as was reported in various other cell types immunostained with anti-S-100 protein antibodies. The present results support the view that interstitial cells of the monkey Macaca irus pineal gland may be of astroglial origin.

Acute effect of propranolol on splanchnic circulation in normal and portal hypertensive rats

Propranolol decreases portal venous pressure in patients with cirrhosis but no method is available in man to study the effect of this beta-blocker on splanchnic organ blood flow. Because in rats, the microsphere method allows evaluation of regional blood flow, the acute effect of propranolol on both splanchnic and systemic circulations was studied in normal rats and in rats with portal hypertension due to portal vein stenosis. Portal venous pressure significantly decreased during propranolol administration in normal (5.6 +/- 1.0-4.7 +/- 1.1 mm Hg; mean +/- SD) as well as in portal hypertensive rats (11.7 +/- 2.3-10.3 +/- 1.8 mm Hg). Propranolol slightly decreased cardiac output and arterial pressure in all rats. Portal tributary blood flow was significantly reduced by propranolol in normal rats (17.4 +/- 3.0-11.3 +/- 2.2 ml/min) and in portal hypertensive rats (23.7 +/- 5.0-16.6 +/- 3.3 ml/min). Accordingly vascular resistance of the different organs in the portal venous territory increased in these rats receiving propranolol. The percentage of the decrease in portal tributary blood flow was significantly more marked than the percentage of reduction in cardiac output in portal hypertensive rats but, in normal rats, these percentages were parallel. Hepatic arterial blood flow did not change or slightly increased and, consequently, hepatic arterial vascular resistance decreased. These findings further clarify the marked effects of propranolol on splanchnic circulation.

Morphofunctional modifications associated with the inhibition by estradiol of MtTF4 rat pituitary tumor growth

The MtTF4 pituitary tumor has been induced in Fischer rats by chronic estrogen administration. Recently, we reported that sustained pharmacological treatment of Fischer rats with 17 beta-estradiol inhibited the growth of the MtTF4 tumor transplanted s.c. The present work describes the associated morphofunctional changes occurring in the tumor during 17 beta-estradiol inhibition. It is shown that a 7-day 17 beta-estradiol treatment resulted in an increase of the surface area of cells, nuclei, nucleoli, Golgi complexes, and rough endoplasmic reticulum and an increase in the number of euchromatin-rich nuclei. Flow cytometry analysis of DNA distribution suggested that estradiol affects the cell progression through the early S phase. The ratio of RNA to DNA increased significantly, reflecting cell hypertrophy. Moreover, there was a significant increase in tumor prolactin concentration and a marked enhancement in the intensity of the immunocyto-chemical reaction with rat prolactin antiserum. On the other hand, cell mitoses were dramatically decreased. These morphofunctional changes indicate that the inhibition of the tumor growth by estradiol is accompanied by an evolution of the tumor cell population towards a more differentiated state. However, it cannot be decided whether 17 beta-estradiol induces a shift from a proliferative state to a differentiated state or whether 17 beta-estradiol treatment results in a selection of a subpopulation of tumor cells that are slow growing and more differentiated.

A human beta-endorphin pituitary adenoma

A beta-endorphin (beta END)-containing pituitary adenoma was demonstrated by immunocytochemical, biochemical, and ultrastructural methods in a 43-yr-old man who had impotence, slight testicular atrophy, and an enlarged sella turcica (grade II0), but no manifestations of Cushing's disease. Preoperative hormone data revealed hyperprolactinemia (97 ng/ml), low plasma cortisol levels without circadian rhythm, undetectable plasma ACTH, and normal plasma FSH and LH levels, with an impaired response to LRH. After hypophysectomy, these hormone levels normalized and responded normally to dynamic tests. Immunocytochemically, 30% of the tumor cells reacted only with beta END antiserum. beta END immunoreactivity was the only component revealed by RIA and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A characteristic ultrastructural aspect is also described. These findings demonstrate dissociation in the secretion of the proopiomelanocortin-derived peptides and suggest a relationship between hyperprolactinemia and tumor secretion of beta END.

Immunocytochemical study of Wulzen's cone of the bovine pituitary

The Wulzen's cone of the bovine adenohypophysis presents a variable development and general arrangement. It is joined to the pars intermedia with no intervening connective tissue. It is covered by a single layer of cubical cell epithelium on the side of the hypophysial cleft. Immunofluorescence reveals the presence of different glandular cell types. The most abundant cells are those demonstrated by an anti-oPRL antibody and are either isolated or clustered. Other cells react with anti-hGH, anti-bLH, anti-beta aLH or anti-beta hTSH antibodies. Some cells react simultaneously with anti-beta MSH, anti-1-24ACTH, anti-17-39ACTH, anti-beta LPH and anti-beta endorphin antibodies. Cell types other than the numerous prolactin cells appear only as isolated elements. We did not observe cells reacting with anti-leu-enkephalin, anti-met-enkephalin or anti-calcitonin antibodies either in the Wulzen's cone or in the pars distalis or pars intermedia.

Spontaneous pituitary tumors in the Wistar/Furth/Ico rat strain. An animal model of human prolactin adenoma

Twenty-three spontaneous pituitary tumors in 58 rats of Wistar/Furth/Ico strain were studied. The incidence is 38% in rats older than 10 months; it rises with age, with a maximum at 28-32 months (68.7%) and is higher in females (71.4%) than in males (35%) over 17 months. Light-microscopic and immunocytochemical studies revealed 20 prolactinomas in 19 rats (19/58, 32.7%) and 3 spongiocytic nonimmunostaining adenomas (3/58, 5.2%). The prolactinoma is often hemorrhagic. The cells, often arranged in sheets and agranular, are mostly positive with anti-rat prolactin (rPRL) serum. They have few polymorph granules and a well-developed rough endoplasmic reticulum. In the spongiocytic adenoma, the cells are arranged in cords. Their cytoplasm is slightly vacuolated. In prolactinoma-bearing rats, the mean plasma PRL value was 213 +/- 72.5 microgram/1 (SEM) (N = 15 +/- 1.8 microgram/1 [SEM]). A linear correlation was found between the logarithm of the tumoral pituitary weight or of the tumor size and the logarithm of the prolactinemia. Because of the analogies between these rat prolactinomas and 57 human prolactinomas, the Wistar/Furth/Ico rat strain is considered as a good animal model.

Human pituitary gonadotropic adenoma; histological, immunocytochemical, and ultrastructural and hormonal studies in eight cases

Among 230 surgically removed pituitary adenomas, eight tumours showing immunostaining gonadotropic cells and elevated intratumours gonadotropin concentrations have been detected (frequency: 3.5 per cent.). By light microscopy the tumours were composed of agranular cells and generally PAS negative cytoplasm. The immunofluorescence technique revealed the presence of immunoreactive FSH (beta-subunit) alone in two cases, of both FSH and LH in six cases with immunoreactive beta endorphin in two of them. By electron microscopy, the cells contained an often dilated moderately or well developed rough endoplasmic reticulum, secretory granules measuring 150 nm to 200 nm which varied in electron density, and numerous microtubules. Basal plasma FSH and LH levels were simultaneously elevated in two cases; FSH levels alone were elevated in two cases; in three cases, both FSH and LH plasma values were normal. FSH and LH intratumour concentrations were simultaneously elevated in five cases; FSH alone was elevated in two cases. In all cases, the concentrations of the other hormones were negligible, except in two cases where beta endorphin concentration was elevated. The comparison of the immunocytochemical findings, the hormonal plasma levels and intratumour concentrations showed a good relationship between the immunoreactivity of the tumour and the intratumour RIA. The gonadotropic adenoma is uncommon but not rare. Its diagnosis is possible if immunocytochemical techniques are applied.

Immunohistochemical localization of FSH and LH in the pars distalis of vervet (Cercopithecus aethiops) and baboon (Papio hamadryas) pituitaries

Antisera against oLH, beta oLH and beta hFSH were used to localize gonadotropic cells in the pars distalis of Cercopithecus aethiops and Papio hamadryas. Three separate cell types were observed for FSH and LH: 85% of immunohistochemically identified gonadotropic cells reacted to all the various antisera; 10% reacted with the anti-beta oLH antibody only; and 5% with the anti-beta hFSH antibody only. Comparisons between adjacent serial sections treated with various antisera, other than anti-gonadotropic hormones, demonstrated that the "gonadotropic cells" of these monkeys did not respond to these antisera.

[Immunohistochemical individualization of adenohypophyseal thyrotropic cells in the monkey Macaca irus, using a human anti-beta-TSH antibody]

Using the indirect immunofluorescence technique and an antiserum against the specific beta subunit of human TSH, selective immunocytochemical staining was localized in a cell population of the pars distalis of the monkey Macaca irus. These thyrotropic cells, which were positive to aldehyde fuchsin, Alcian blue, and PAS, were localized on the one hand in the ventro-medial zone of the pars distalis, especially alongside the large vessels of this region, and on the other in the zona tuberalis, i. e. at the bottom of the pars tuberalis. Some cells, sparsely distributed, were seen in the posterior part of the lateral lobes of the pars distalis, in the vicinity of the pars intermedia. No thyrotropic cells were encountered in pars tuberalis. Pars intermedia and posterior lobe contained no cells immunoreactive to beta-hTSH. In females, the thyrotropic cells were more numerous and larger than in males. Generally the thyrotropic cells were round or oval in shape, sometimes they were polygonal.

Immunohistochemical study of the pars tuberalis of the adenohypophysis in the monkey, Macaca irus

The pars tuberalis of the hypophysis in the monkey Macaca irus encompasses the hypophysial stem up to the median eminence. Histologically, it consists of several layers of chromophobic cells. A few PAS-positive cells also stainable with Alcian blue (pH 3.0) can be observed among the unstained elements. Using the indirect immunofluorescence antibody technique, scattered immunoreactive cells were revealed with the anti-beta oLH antibody; these cells did not react with the anti-beta hFSH antibody. In contrast, the immunoreactions to anti-hGH, anti-hPRL, anti-ACTH, anti-MSH, anti-LPH and anti-endorphin sera were completely negative. Single cells reacting with the anti-beta hTSH serum were observed at the inferior end of the hypophysial stalk (zona tuberalis), i.e., beyond the pars tuberalis proper. These results are compared with data reported in the literature.

[Cilia-centriole-Golgi apparatus relationships in the glandular cells of the anterior pituitary of the hedgehog (Erinaceus europaeus L)]

Antehypophysial somatotropic and prolactinic cells of the Hedgehog have isolated cilia composed by a ring of 9 or 8 double tubules with or without a central tubule; this single cilia is in relation with a basal corpuscule. A granulo-filamentous neck joins the basal corpuscule to the subjacent centriole; from this granulo-filamentous neck accompanying the complex basal corpuscule-centriole, microtubules and striated filaments extend towards the Golgi apparatus. The single cilia, probably of chemoreceptor significance, appears in relation with the Golgi complex, a zone of granule formation.

[Immunohistochemical study of adenohypophysis cells reacting with antibodies against peptides of the opiocortine group in rock squirrels (Citellus variegatus Erxleben)]

Indirect immunofluorescence technique with anti-1-24ACTH, anti-17-39ACTH, anti-alpha and anti-beta endorphins, anti-beta LPH sera has allowed us to detect a cellular type in the anterior lobe of the Rock squirrel (Citellus variegatus) which react simultaneously with these five antisera. These cells are localized in the whole pars distalis and appeared either in clusters or dispersed; immunoreactive cells are regularly disposed along the pituitary cleft. Some cells of the intermediate lobe react with anti-1-24ACTH, anti-17-39ACTH and anti-beta LPH antisera, but not all these cells react with anti-endorphins antisera.

Morphological and biochemical relationships in 31 human pituitary adenomas with acromegaly

In 22 pure GH cell adenomas and 9 mixed GH cell-prolactin cell adenomas with acromegaly, we compare the morphological and functional data (secretory activity and granular appearance) with GH levels (radioimmunoassays) in the blood and in the tumor. According to morphological criteria, the secretory activity is marked in 13 cases (Group I), mild in 9 cases (Group II), and weak in 9 others (Group III). The mean values of the plasma GH levels in the 3 groups (80 ng/ml plus or minus 22; 26.5 ng/ml plus or minus 2; and 16.89 ng/ml plus or minus 2 respectively) are significantly different. In 17 densely granulated adenomas and 14 sparsely granulated adenomas, the plasma GH values were very variable. The mean levels of these 2 groups (49.76 ng/ml plus or minus 22 and 41.8 ng/ml plus or minus 7.8 respectively) are not significantly different. The GH concentrations in the tumor were also very variable (358 to 78,900 ng/mg). Their highly significant relationship with the granular appearance is an indirect proof of the granular localisation of GH. We distinguish between 4 functional aspects of the GH cell adenoma which define the different levels of synthesis, storage, and excretion. The secretory activity of the GH adenomatous cell varies with the adenomas and differs from that of the normal cell.

Immunocytochemical evidence for the presence of somatostatin-like immunoreactivity in scattered cells of the duct system of the submandibular glands in the monkey, Macaca irus

Using the indirect immunofluorescent technique with anti-somatostatin serum, the distribution of scattered cells in the duct system of submandibular glands in the Monkey, Macaca irus has been assessed. In both males and females, these cells are located only in some portions of the duct system, e.g. striated ducts and excretory ducts. No immunoreactive cells were observed in the intercalated ducts or in secretory endpieces. The lymphatic node constantly adjacent to the submandibular gland did not contain immunoreactive cells. In the parotid glands, no immunoreactive cells to antisomatostatin immuneserum were ever observed.

[Contribution of immunohistochemistry to the cytological study of the adenohypophysis]

In the first chapter, the initial studies using immuno-histochemical methods for the cytological analysis of the adenohypophysis are presented; the different trends of the actual groups of research workers are summarized. In the second chapter are described, with details utillsation, some ser viceable techniques for experimental or anatomo-pathological studies of the pituitary gland; immunization of animals against hypophysial hormones, application to the study of the hypophysis (conditions of fixation, analysis of the subsequent times of histological techniques, immunohistochemical reactions [immuno-fluorescence and immuno-enzymatic reactions], controls of these reactions, applications on semi-thin and ultra-thin sections). In the third charpter are studied the results of this immunohistochemical analysis of the mammalian hypophysis: description of different cell types first in the anterior lobe then in the intermediate lobe; these observations are discussed. A special subdivision concerns the study of the human pituitary gland in normal and pathological conditions, in adults and foetuses. In the fourth chapter the results obtained in the study of the adenohypophysis of non mammalian Vertebrates: Fish, Amphibians, Reptiles, and Birds, are grouped. An extensive bibliography concludes this review (references until 1977). Illustrations, furnished by several french workers, are adapted to the different descriptions.

Immunofluorescent identification of somatotropic and prolactin cells in the anterior lobe of the hypophysis (pars distalis) of the monkey,Macacus irus

Using antibodies against human growth hormone and ovine prolactine,it is possible to identify somatotropic and prolactin cells in the anterior lobe of the hypophysis (pars distalis) of the monkey, Macacus irus. These cells are present in both adult and infant male and female monkeys. The density of the somatotropic cells is greater at the periphery of the anterior lobe. Prolactin cells are of two types: one type is dispersed throughout the pars distalis and consists of small and large cells, the other type forms clusters of large cells.

[A case of oncocytic adenoma of the pituitary gland with galactorrhea and hyperprolactinemia]

A tumor of hypophysis, with suprasellar expansion, was removed surgically in a 68 years old woman with panhypopituitarism and galactorrhea. Light and electron microscopy studies have shown an oncocytoma. One year after pituitary ablation and cobaltherapy, the patient had normal pituitary functions and galactorrhea had disappeared. Since the prolactin cells were outside the adenoma and the prolactin secretion became normal after surgery, we can assume that galactorrhea was presumably due to the compression of the pituitary stalk by oncocytoma.

[Description of the folliculo-stellate cells in the anterior hypophysis of the monkey Macacus irus]

Folliculo-stellar cells are present in the anterior lobe of hypophysis of the monkey Macacus irus. These cells limit strait cavities in which one can observe microvillosites at the apical pole of the cells. The folliculo-stellar cells possess long and thin fibers which insert themselves between different types of granular cells and sometimes extend to the peri-capillar regions. Numerous organelles are present in these folliculo-stellar cells, especially microfilaments.