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At least 19 recordsLinked to original sources
PubMed1986

Angiotensin II receptors in adrenal gland, pituitary gland and brain of sino-aortic denervated rats.

Angiotensin II (ANG II) binding sites were quantified in individual adrenal and pituitary glands and brain nuclei of sino-aortic denervated (neurogenically hypertensive) and sham-operated rats by incubation of 16-microns tissue sections with 125I-[Sar1] Ang II, autoradiography, computerized microdensitometry and comparison with 125I-standards. In the anterior pituitary, the number of ANG II binding sites (Bmax) was increased in sino-aortic denervated rats, 764 +/- 39 versus 2025 +/- 340 fmol/mg protein in sham-operated versus sino-aortic denervated. In the adrenal medulla the Bmax was decreased in sino-aortic denervated rats, 3313 +/- 71 versus 2736 +/- 181 fmol/mg protein in sham-operated versus sino-aortic denervated. There were no significant changes in adrenal zona glomerulosa ANG II binding capacity. In the nucleus of the solitary tract the Bmax was decreased, from 1422 +/- 22 fmol/mg protein in sham-operated to 370 +/- 52 fmol/mg protein in sino-aortic denervated rats. These results indicate that changes in ANG II binding occur in peripheral tissues and brain of neurogenic hypertensive rats. Our findings suggest that both peripheral and central ANG II may be associated with the pathophysiology of neurogenic hypertension.

Adrenal Glands↗
PubMed1993

Aging and the human pituitary gland.

Pituitary glands obtained at autopsy from 41 men (90 to 97 years old) and 45 women (90 to 98 years old) were studied histologically and immunohistochemically to determine the age-related alterations. Pituitaries from patients 30 to 39 years old (48 cases) and 60 to 89 years old (187 cases) were also studied and served as controls. Interstitial, perivascular fibrosis was seen in 88% of the aged adenohypophyses and, although significantly more intense than that in those of the fourth decade of life (P < 0.001), was similar to that noted in those of the seventh to ninth decades. Pituitaries of men were significantly more fibrotic than were those of women (P < 0.05). In proportion to the extent of fibrosis, the number of somatotrophs decreased in the lateral wings, whereas other cell types did not change quantitatively. Small deposits of amyloid and of iron were detected in seven and three cases, respectively. Squamous metaplasia in cells of the pars tuberalis was noted in 29%. The incidence of "basophil invasion" (the presence of corticotrophs in the posterior lobe) was 30%, a figure similar to that in younger controls. Granular cell tumorlets were detected in four aged neurohypophyses (5%), a frequency similar to that in control glands. Pituitary adenomas (two null cell, two lactotroph, and one corticotroph adenomas) were found of three men and two women in the study group. This 9% incidence of adenomas did not differ from that observed in the fourth decade (8%) or seventh decade (10%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1997

Urocortin expression in human pituitary gland and pituitary adenoma.

Urocortin is a recently identified neuropeptide of the CRF family in the mammalian brain, but its expression in human tissue has been little studied. In this study, we examined urocortin expression in human anterior pituitary gland and pituitary adenomas by RIA, high performance liquid chromatography, immunohistochemistry, messenger ribonucleic acid (mRNA) in situ hybridization, and reverse transcriptase-PCR. Immunoreactive urocortin concentrations in normal pituitary tissue extract were 103.25 +/- 39.05 ng/g wet wt (mean +/- SEM; n = 4), and their levels were all significantly higher than those in other portions of central nervous system of the same subjects. High performance liquid chromatography analysis of human pituitary extract demonstrated a single peak corresponding to that of the expected chromatographic mobility of synthetic human urocortin-(1-40). Urocortin-immunoreactive cells were detected in the anterior pituitary gland. Neither urocortin-immunoreactive nerve fibers nor cells were detected in the posterior lobe. Immunostaining in serial mirror tissue sections revealed that 76.55 +/- 3.06% of urocortin-immunoreactive cells expressed GH immunoreactivity, whereas 22.25 +/- 3.02% and less than 1% of urocortin-immunoreactive cells expressed PRL and ACTH, respectively. mRNA hybridization signals of urocortin were also detected in urocortin-immunopositive pituitary cells. The reverse transcriptase-PCR analysis demonstrated a 145-bp RNA band corresponding to that of the expected length of urocortin in all cases of normal pituitary glands examined (n = 3). We also immunostained urocortin in 52 cases of human anterior pituitary adenomas, including GH-producing adenomas (n = 14), ACTH-producing adenomas (n = 13), PRL-producing adenomas (n = 11), and nonfunctioning hormonally inactive adenomas (n = 14). No urocortin immunoreactivity was detected in these adenoma cells, except for one case of GH-producing adenoma and one case of nonfunctioning adenoma. We also performed mRNA in situ hybridization in 27 adenomas. No hybridization signals were detected in these adenomas, except in two cases. The results described above indicated that urocortin is synthesized in human anterior pituitary cells and may play an important role in biological features of normal pituitary gland, possibly as an autocrine or a paracrine regulator

Adenoma↗
PubMed2001

Expression of interleukin-6, interleukin-6 receptor (gp80), and the receptor's signal-transducing subunit (gp130) in human normal pituitary glands and pituitary adenomas.

Interleukin-6 (IL-6) is an important cytokine in cell proliferation and differentiation in several organs. It has also been reported that IL-6 plays a role in secretion or release of pituitary hormones in pituitary hormone-secreting cells and pituitary adenomas, but convincing data in situ have not yet been reported. In this study, we examined the participation of IL-6 in the production of pituitary hormones and the differences between human normal pituitary glands and pituitary adenomas by determination of the localization or expression of IL-6, IL-6 receptor (IL-6R, gp80), and the signal-transducing subunit (gp130) of the receptor using immunohistochemical staining and RT-PCR. IL-6 was mainly expressed in ACTH- and FSH/LH-secreting cells in normal pituitary glands, as shown by double staining. gp 80 and gp130 were coexpressed in almost all GH- and PRL-secreting cells and in approximately 30% of FSH/LH-secreting cells. RT-PCR showed that IL-6 mRNA was expressed in only one of all the pituitary adenomas examined, whereas gp 80 and gp 130 mRNAs were detected in all these pituitary adenomas. In conclusion, IL-6 was mainly expressed in ACTH- and FSH/LH-secreting cells, and the receptors were expressed in GH-, PRL- and FSH/LH-secreting cells in human normal pituitary glands. Furthermore, our data emphasized that the mechanism of IL-6 function in human pituitary adenoma cells is distinct from that in normal pituitary cells.

Adenoma↗
PubMed1978

An immunohistochemical study of epithelial cells in the posterior lobe and pars tuberalis of the human adult pituitary gland.

Pituitary glands were examined using reference staining (hematoxylin and eosin, periodic acid-Schiff and alcian blue) and the peroxidase-labeled antibody method, for 1) "invading" anterior cells in the posterior lobe, 2) intermediate colloid forming follicles, and 3) pars tuberalis cells. The results showed: 1) that the majority of cases possessed "invading" anterior cells of various amount. Most of these cells were positive for ACTH1-18, ACTH17-39 and betaMSH. However, on a few occasions, scattered GH, PRL, FSHalpha, FSHbeta, LHbeta and even TSHbeta cells were also present. 2) Colloid forming follicular cells were mostly ACTH cells, but also contained occasional other hormone-secreting cells. Hormone negative cells were correlated with salivary type epithelium. Well established acinic type salivary glands and ciliated epithelium were negative for any hormones immunohistochemically. 3) Pars tuberalis cells were predominantly gonadotrophs but also included TSHbeta and ACTH cells. Some cells appeared to contain both FSHbeta and LHbeta. When these cells underwent squamous metaplasia, they seemed to lose their hormone secreting activity.

Adrenocorticotropic Hormone↗
PubMed1975

Comparison of two isozymes of carbonic anhydrase in the rat anterior pituitary gland and pituitary tumors.

Two isozymes of carbonic anhydrase (EC 4.2.1.1.) were compared in the anterior pituitary gland of non-tumor-bearing rats and in the hormone-secreting pituitary tumors. In contrast to the pituitary gland, which contained 60 to 70% of the total carbonic anhydrase in the particulate subcellular fraction, three hormone-secreting pituitary tumors were devoid of the particulate (Triton X-100-solubilized)enzyme activity. Another pituitary tumor, 7315a, contained particulate carbonic anhydrase, but the activity was only 45% of the activity of normal pituitary gland. During the development of the rat brain, the particulate (Triton X-100-solubilized) carbonic anhydrase activity was undetectable in prepartions up to 21 days of age (body weight, 47 g). After that age, the carbonic anhydrase activity in the particulate fraction increased rapidly and reached the adult level at 37 days (body weight, 120 g), while the activity in the soluble fraction increased gradually after birth and then reached a plateau at 30 days (body weight, 81 g). These data show that the isozyme pattern of carbonic anhydrase in pituitary tumor tissue resembles the pattern in fetal cells more than the pattern in adult tissue.

Animals↗
PubMed1984

Autoregulation of follicle-stimulating hormone secretion in the hamster: evidence for control at the level of the anterior pituitary gland.

Pituitary tissue obtained from proestrous, phenobarbital-treated hamsters was placed in organ culture, and the release rates of FSH and LH were monitored. Addition of LHRH to the culture medium increased gonadotropin release rates. Preincubation of pituitaries in medium that contained 1 microgram purified FSH ( NIADDK rat FSH-I-5) resulted in enhanced basal and LHRH-induced FSH release rates. Full expression of FSH hypersecretion by pituitary tissue occurred after 3-h exposure to purified FSH. This phenomenon appears to require adequate tissue calcium concentrations. Further, exposure of pituitaries to purified FSH slightly but significantly enhanced basal but not LHRH-stimulated LH release compared with that in untreated controls. Experiments that employed labeled FSH, reduced exposure time to purified FSH, or decreased calcium concentration in the medium proved that the increased FSH secretory rate was not due to contamination of the medium with the purified FSH used to stimulate the pituitary. These studies suggest that FSH has the ability to influence its own secretion by an action at the level of the anterior pituitary gland.

Animals↗
PubMed1998

PACAP colocalizes with luteinizing and follicle-stimulating hormone immunoreactivities in the anterior lobe of the pituitary gland.

Pituitary adenylate cyclase activating polypeptide (PACAP) and its close relative vasoactive intestinal polypeptide (VIP) were demonstrated in the anterior pituitary gland. The cells which exhibited PACAP immunoreactivity were oval or round shaped. Their distribution was similar to that of gonadotropes but the number of PACAP immunoreactive cells was less. Double labeling revealed that PACAP immunoreactivity partially colocalized with luteinizing and follicle-stimulating hormone; however, colocalization with other pituitary hormone immunoreactivities was not demonstrated. Our results suggest an autocrine or paracrine role of PACAP in the regulation of pituitary functions.

Animals↗
PubMed1986

Effect of thyrotropin-releasing hormone and dopamine on the in vitro secretion of prolactin by the bullfrog pituitary gland.

Pituitary glands of bullfrogs (Rana catesbeiana) were incubated in medium containing thyrotropin-releasing hormone (TRH) and/or dopamine in order to see their effects on the release and synthesis of prolactin, which was measured by a homologous radioimmunoassay. Prolactin synthesis was measured by monitoring the incorporation of [3H]leucine into prolactin. TRH (0.1-10 ng/ml) stimulated the release of immunoassayable prolactin and newly synthesized [3H]prolactin into the medium in a dose-dependent manner; however, it was ineffective in increasing total prolactin (medium plus pituitary) and the incorporation of [3H]leucine into the total prolactin during the experimental period (20 hr). The TRH-induced elevation of prolactin release was suppressed by the addition of dopamine (5 X 10(-7) M) to the medium.

Animals↗
PubMed1975

Localization of antisera to LHbeta and FSHbeta in the rat pituitary gland.

Pituitary glands from adult male and female rats were stained by the immunocytochemical bridge technique with antisera to ovine LHbeta and human FSHbeta. Peroxidase reaction product was localized in the same PAS-positive cells with both antisera. The cells varied in size and topographical distribution within the pars distalis. These observations support the concept that a single cell type is responsible for the synthesis of both LH and FSH in the rat.

Animals↗
PubMed1979

The computed tomographic appearance of the normal pituitary gland and pituitary microadenomas.

With the use of axial and coronal computed tomography (CT), the authors compared the density, contrast enhancement, and dimensions of normal pituitary glands and pituitary microadenomas. The normal gland appears homogeneous, nearly isodense with brain tissue, and it enhances uniformly. Its upper surface is concave downward or flat and its height 2-7 mm. The cavernous sinuses, the third, fourth, and sixth cranial nerves, the infundibulum, and the adjacent carotid arteries are well demonstrated by CT. Abnormal height and upward convexity of the gland are reliable signs of prolactinoma; abnormal density and enhancement are suggestive signs. CT findings in prolactin- and ACTH-secreting tumors may differ. CT is more sensitive and more specific than polytomography in the diagnosis of pituitary adenoma.

Adenoma↗
PubMedDate not supplied

Magnetic resonance imaging of the normal pituitary gland and pituitary adenoma: preliminary experience with a resistive magnet.

Magnetic resonance (MR) imaging was performed in fifty normal pituitary glands, ten pituitary microadenomas, and twelve adenomas with extrasellar extension using a 0.15 Tesla resistive magnet. The average height of normal glands was 5.6 +/- 1.2 mm, whereas that of microadenomas was 6.8 +/- 1.0 mm. The superior surface and internal texture of these conditions were well delineated. Adenomas that showed extrasellar extension together with surrounding structures were well demonstrated on sagittal and coronal scans. It can be expected that with further technical developments MR imaging will play an important role in the clinical management of pituitary adenomas.

Adenoma↗
PubMed1981

The use of monoclonal antibodies against human chorionic gonadotropin for immunoperoxidase staining of normal placenta, pituitary gland, and pituitary adenomas.

A monoclonal mouse antibody to human chorionic gonadotropin (hCG) was used in a modified unlabeled antibody enzyme-bridge staining method to demonstrate the localization of hCG in normal human placenta, pituitary gland, and six pituitary chromophobe adenomas. Mouse ascitic fluid containing monoclonal antibody could be diluted up to 1:500,000 for detection of hCG in the syncytiotrophoblast, whereas no staining was observed in the pituitary or adenomas even with high antibody concentrations (dilutions from 1:500 upward). Nonspecific background staining was negligible. These results demonstrate that monoclonal antibodies are suitable for immunohistochemical localization of antigens in tissues.

Adenoma↗
PubMed1998

Localization of prohormone convertases 1/3 and 2 in the human pituitary gland and pituitary adenomas: analysis by immunohistochemistry, immunoelectron microscopy, and laser scanning microscopy.

Prohormone convertase (PC) 1/3 and PC2 are involved in post-translational processing of endocrine tissues, including the pancreatic islets and pituitary glands. Our immunohistochemical studies disclosed the presence of PC1/3 and PC2 in non-neoplastic pituitary glands, especially in corticotrophs, gonadotrophs, and thyrotrophs. Among 58 pituitary adenomas obtained by trans-sphenoidal surgery, adrenocorticotropin (ACTH)-secreting adenomas showed a high incidence of the presence of PC1/3 and PC2, i.e., nine of nine cases were positive for ACTH. Five of nine cases showed consistency between PC2 localization and alpha-melanocyte stimulating hormone immunoreactivity, which suggests the functional correlation between PC2 and the processing of ACTH. In four cases, we observed inconsistency in immunolocalization, which suggested the possibility of inactive PC2 and abnormal processing of alpha-melanocyte stimulating hormone. The high incidence of PC1/3 and PC2 in nonfunctioning adenomas might be related to the processing of chromogranin A.

Adenoma↗
PubMed1985

The medical treatment of the hypersecreting pituitary gland.

Pituitary adenomas may produce local endocrine and neurological effects, as well as systemic metabolic complications due to hormonal hypersecretion. Medical therapy with pharmacological agents has been developed and is based on the neurotransmitter regulation of normal pituitary hormonal secretion. 189 patients with secretory pituitary adenomas underwent medical therapy for the hypersecretory state. 156 of these were prolactin-secreting adenomas, 16 of which were in males. The response of bromocriptine was almost universal with lowering of serum prolactin and reversal of the clinical symptoms, as well as tumor shrinkage of most large adenomas with suprasellar extension. 23 patients with acromegaly were treated with bromocriptine, with 11 noting clinical improvement, and decreased tumor size in two. Five patients with Cushing's disease were treated with cyproheptadine, with only one showing a biochemical and clinical improvement. Two patients with Nelson's syndrome each had progressive tumor growth stabilized with cyproheptadine and bromocriptine in one, and sodium valproate in the other. There appears to be a role for medical therapy in the majority of prolactin-secreting pituitary tumors, some growth hormone secreting pituitary tumors, and selected adrenocorticotropin secreting-pituitary tumors.

Adenoma↗
PubMed1999

Expression of Ptx1 in the adult rat pituitary glands and pituitary cell lines: hormone-secreting cells and folliculo-stellate cells.

The pituitary homeobox1 gene (Ptx1) was initially identified as encoding a pituitary-restricted transcription factor for the proopiomelanocortin (POMC) gene. In order to elucidate the expression pattern of the Ptx1 protein, we investigated the localization of the protein in adult rat pituitary gland and in various pituitary cell lines. We produced an antibody specific for Ptxl protein, and confirmed its specificity by Western blot analysis. Immunohistochemically, many nuclei in the anterior pituitary cells as well as in the intermediate cells were positive for Ptxl staining with this specific antibody. Immunohistochemical double staining revealed the presence of Ptx1 not only in all types of hormone-secreting cells but also in some folliculo-stellate (FS) cells. Furthermore, the expression of Ptx1 mRNA was confirmed in various pituitary cell lines and in the FS cell line by using the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Our studies indicated that Ptxl may not only play a role as a basic transcriptional factor for production of various hormones, but may also play some important role(s) in FS cells. Possible synergistic actions with other factors remain to be investigated. The novel finding of Ptx1 in FS cells is of particular interest, and may suggest that FS cells and hormone-secreting cells are derived from a common cellular ancestor.

Animals↗