[Microanatomy and functional MRI study of arcuate fasciculus and superior longitudinal fasciculus].

Objectives: To explore the microanatomy and functional MRI(fMRI) of arcuate fasciculus(AF) and superior longitudinal fasciculus(SLF),and to analyze their functions. Methods: Ten normal adult cadaveric head specimens (20 cerebral hemispheres) were fixed with 10% methanal at the Translational Research Institute for Neurological Disorders of the Wannan Medical Collegefrom February to December 2022.The Klingler fiber dissection technique was utilized to perform white matter fiber dissection,with a magnification ranging from 6 to 40.The study focused on the microanatomical structures of the AF and SLF,aiming to explore their relationships with deep brain fibers.Furthermore, six healthy adult volunteers who underwent fMRI of the brain were included.The collected diffusion tensor imaging (DTI) data were processed and integrated with the microanatomical findings for a comprehensive analysis. Results: After removing the gray matter of the cerebral cortex,the superficial U fibers were exposed.The long association fibers that beneath the U fibers were the AF and SLF,which were the main long association fibers in the superficial layers of the brain.The AF could be divided into dorsal and ventral parts,while the SLF could be divided into Ⅰ,Ⅱ,and Ⅲ.SLF Ⅰ lied within the upper bank of the cingulate sulcus,travels medial to the callosal sulcus.The SLF Ⅱ,Ⅲ,and the AF were located on the lateral surface of the brain.By removing the gray matter of the insular cortex and the extreme capsule,exposing the external capsule and claustrum.Subsequently,the AF and SLF Ⅱ,Ⅲ were dissected,revealing the corona radiata and sagittal stratum,along with other deep brain fibers.During the dissection,it was observed that there was a close connection between the AF,SLF Ⅱ,and the deep brain fibers.Furthermore,in the regions above the lateral fissure of the cerebral hemisphere,there was no direct connection of long association fibers between the gray matter cortex and the deep U fibers in the coronal plane.These findings were further supported by DTI studies. Conclusions: The AF and SLF are the major long association fibers that located in the superficial layers of the brain,and closely connect to the gray matter cortex and U fibers,even closely relate with deep brain fibers.In the regions above the lateral fissure of the hemisphere,only the AF and SLF Ⅱ and Ⅲ serve as superficial long association fibers in the anterior-posterior direction.These fibers are likely involved in the transmission of brain functional information between the top and bottom gray matter cortex in the coronal plane above the lateral fissure.

[Feasibility analysis on reducing iodine delivery rate of coronary CT angiography with 100 kVp to 60% of 120 kVp standard].

Objective: To investigate the feasibility of reducing the iodine delivery rate (IDR) of coronary CT angiography(CCTA)with 100 kVp to 60% of 120 kVp standard. Methods: A total of 205 patients (105 males and 100 females, aged from 23 to 87 years) underwent CCTA due to suspected coronary artery disease in Department of Radiology of Peking University Third Hospital from February to July 2022 were enrolled. Those patients were divided into five subgroups according to their body weight: <50 kg, 50 to 59 kg, 60 to 69 kg, 70 to 79 kg and ≥ 80 kg, respectively. All the cases were scanned with 100 kVp tube voltage and combined with mixed iterative reconstruction technology KARL 3D. The IDR injection protocol was set to 60% of the 120 kVp IDR standard (10% lower than the guideline), and the IDR of each group was 0.9, 1.0, 1.1, 1.3 and 1.4 gI/s, respectively. The CT attenuations (CT value) and noise (SD value) of the aortic root, proximal left anterior descending branch and the distal segments of the right coronary artery, the signal-to-noise ratio (SNR) and contrast noise ratio (CNR) of proximal left anterior descending branch and the distal segments of the right coronary artery, the whole subjective image quality scores of the coronary artery, and effective dose (ED) of CCTA in the five groups were compared. The One-way ANOVA or Kruskal-walls test was used for statistical analysis. Results: There was no significant difference in CT attenuations and noise of aortic root, proximal left anterior descending and the distal segments of the right coronary artery, SNR and CNR of proximal left anterior descending branch and the distal segments of the right coronary artery, and subjective image quality scores among the five groups (all P>0.05). The difference of the dosage of contrast medium and ED among the five groups were statistically significant (all P<0.05). The dosage of contrast medium in the five groups were 30, 34, 38, 43 and 48 ml, and the ED in the five groups was 2.24 (1.88, 2.56), 2.62 (2.24, 3.17), 2.70 (2.48, 3.20), 4.13 (3.85, 4.40) and 4.44 (4.01, 5.02) mSv, respectively. Conclusion: It is feasible to reduce the IDR injection protocol of coronary CT angiography with 100 kVp to 60% of the standard injection protocol with 120 kVp, which is worthy of promotion.

Lidocaine Stimulates the Function of Natural Killer Cells in Different Experimental Settings.

BACKGROUND: One of the functions of natural killer (NK) cells is to eliminate cancer cells. The cytolytic activity of NK cells is tightly regulated by inhibitory and activation receptors located in the surface membrane. Lidocaine stimulates the function of NK cells at clinically relevant concentrations. It remains unknown whether this effect of lidocaine has an impact on the expression of surface receptors of NK cells, can uniformly stimulate across different cancer cell lines, and enhances the function of cells obtained during oncological surgery. MATERIALS AND METHODS: NK cells from healthy donors and 43 patients who had undergone surgery for cancer were isolated. The function of NK cells was measured by lactate dehydrogenase release assay. NK cells were incubated with clinically relevant concentrations of lidocaine. By flow cytometry, we determined the impact of lidocaine on the expression of galactosylgalactosylxylosylprotein3-beta-glucuronosytranferase 1, marker of cell maturation (CD57), killer cell lectin like receptor A, inhibitory (NKG2A) receptors and killer cell lectin like receptor D, activation (NKG2D) receptors of NK cells. Differences in expression at p<0.05 were considered statistically significant. RESULTS: Lidocaine increased the expression of NKG2D receptors and stimulated the function of NK cells against ovarian, pancreatic and ovarian cancer cell lines. Lidocaine also increased the cytolytic activity of NK cells from patients who underwent oncological surgery, except for those who had orthopedic procedures. CONCLUSION: Lidocaine showed an important stimulatory activity on NK cells. Our findings suggest that lidocaine might be used perioperatively to minimize the impact of surgery on NK cells.

[Endoscopic dissection of perforating veins: surgical and pharamacoeconomic aspects].

Analysed herein are the outcomes of endoscopic dissection of perforating veins (EDPV) in a total of 113 patients presenting with chronic venous insufficiency (CVI). Of these, 71 patients suffered from varicose disease (VD) and 42 subjects had postthrombophlebic disease (PTPD). 54.9 % of the patients were in CEAP class C5-6. All of them underwent EDPV combined with simultaneous phlebectomy or crossectomy. The control group consisted of 26 patients who endured the classic operation by the Linton technique. All those engaged underwent ultrasonograp-hic angioscanning, with part of them being subjected to distal phlebography. Postoperative complications were observed in 2.65 % of the Study Group patients subjected to the EDPV procedure combined with phlebectomy, and in 34.5 % of those who had endured the Linton's operation. Both subjective and clinical assessment of surgical outcomes made it possible to define the obtained results as good in 82.3% of cases, as fair in 14.16%, and in four patients with PTPD, the results were defined as poor. The hospital stay following surgery in the Study Group patients amounted to 7.3+/-0.54 bed days, while in those of the Comparison Group it was 21.2+/-0.74 bed days. The obtained findings make it possible to conclude that the scope of surgical interventions in patients presenting with CEAP class C4-6 CVIs should in the majority of cases amount to simultaneous EDPV and radical venectomy. Such policy reduces the duration of the hospital stay 2.7-fold, with a 1.76-fold decrease in the treatment costs.

First Report of Pythium splendens Associated with Severe Wilt of Muskmelon (Cucumis melo) in Oman.

Muskmelon (Cucumis melo L.) is one of the most important vegetable crops in Oman. In the fall of 2004, sudden wilt was observed in muskmelon grown in a field at Sultan Qaboos University, Muscat. The disease was characterized by rapid collapse of vines and muskmelon plants at the fruit production to maturation stage, associated with brown-to-dark brown rotted primary and secondary roots. The disease resulted in death of more than 85% of muskmelon plants in that field. On potato dextrose agar (PDA), with published methods (1), Pythium spp. were consistently isolated from crowns and roots of plants showing wilt symptoms. Further identification of five isolates of Pythium with sequences of the internal transcribed spacer (ITS) of the ribosomal DNA (1) using ITS1 and ITS4 primers produced a nucleotide sequence 806 bp long, which was identical among all isolates. Comparison with sequences deposited at the National Center for Biotechnology Information revealed 100% nucleotide similarity to a previously published sequence (Accession No. DQ381808) of isolate P091 of P. splendens from cucumber from Oman, for which identification has also been confirmed by morphological characteristics. The sequence of one isolate of P. splendens (P222) was assigned GenBank Accession No. EF546436 and deposited at CBS under Accession No. CBS121855. In pathogenicity tests conducted in a greenhouse, P. splendens induced damping-off symptoms on 7-day-old muskmelon seedlings and also reproduced the same wilt symptoms observed in the field when 2-month-old muskmelon plants were inoculated with 3-day-old P. splendens grown in PDA. To our knowledge, this is the first report of association of P. splendens with wilt of muskmelon in Oman. Reference: (1) A. M. Al-Sa'di et al. Plant Pathol. 56:140, 2007.

First Report of Rust Caused by Tranzschelia discolor on Peach in Oman.

Peach (Prunus persica L.) is the primary fruit crop in parts of the northern mountainous regions of Oman. Local cultivars, propagated by seedling, are used to produce fruit for local markets and shade fodder crops planted underneath the peach canopy. In February of 2006, leaf samples showing rust signs and symptoms were collected from Balad Seet, 120 km southwest of Muscat. Angular, yellow spots were observed on leaf upper surfaces with orange sori on the undersides. The disease was observed to be affecting almost 100% of trees, with many leaves having more than 10 sori per leaf. Lesions producing urediniospores were also observed on twigs where spring growth had cracked. Urediniospores typical of Tranzschelia discolor (Fuckel) Tranzschel & M.A. Litv. were obovoid, echinulate, orange-brown, and measured on average 13 to 17 × 26 to 37 µm, with the cell wall 1.3 to 1.8 µm thick at the sides and as much as 5.8 µm thick at the apex. Golden capitate paraphyses were also present, measuring on average 35 to 57 µm long, head 13 to 16 µm in diameter, and tail 4.9 to 6.7 µm wide. Teliospores were not observed because of the time of year of collection. Pathogen identity was confirmed by analysis of a nuclear rDNA sequence spanning from the 5.8S through the ITS-2 into the first 1,000 bp of the 28S gene (1). A voucher specimen was deposited in the U.S. National Fungus Collection (BPI 875341). The voucher's rDNA sequence deposited in GenBank (Accession No. DQ995341) shared 100% sequence similarity with T. discolor (Accession No. DQ354542). Although T. discolor has a worldwide distribution (2), it has not previously been reported from Oman. Improving the quality of peach production in Oman is an agricultural priority because it boosts the economy of smallscale farms in the mountainous regions. This work will facilitate the current research aimed at evaluating cultivar response to rust disease. References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) P. F. Bertrand. Rust. Page 23 in: Compendium of Stone Fruit Diseases. J. M. Ogawa et al., eds. The American Phytopathological Society, St Paul, MN, 1995.

First Report of Leaf Rust by Puccinia triticina on Wheat in Oman.

Wheat (Triticum aestivum L.), cultivated for forage and grain production, is an important crop in the Sultanate of Oman. In April 2005, leaf samples of an unknown local variety showing rust symptoms were collected from Rustaq, 100 km southwest of Muscat. Circular-to-oval, red-brown pustules, typical of uredinia, occurred mostly on the upper surface of leaves on plants nearing maturity. Telia with teliospores were observed on leaf sheaths. The disease was widespread in many fields and was likely to be limiting the yield. Urediniospores typical of Puccinia triticina Erikss. (=P. recondita Rob. ex Desm. f. sp. tritici) were roughly subglobose, measuring 18 to 28 × 20 to 25 µm, echinulate, with 3 to 8 scattered germ pores; teliospores were 2-celled, 34 to 50 × 15 to 17 µm, apex is chestnut brown, lower cell is light yellow, no germ pores (1,2). Pathogen identity was confirmed by nuclear ribosomal large subunit and internal transcribed spacer region-2 DNA analysis (voucher sequence deposited in GenBank, Accession No. DQ664194, voucher specimens deposited in the U.S. National Fungus Collections, BPI 872158 and 872159). Wheat is grown during the winter months in Oman and harvested in May. Although the disease was observed again in 2006, pathogen survival mechanisms are not presently clear, and current research is attempting to confirm its presence on alternate hosts, including grass weeds, and determine the distribution of the pathogen on local wheat land races and imported varieties. To our knowledge, this is the first documented report of P. triticina on wheat in Oman. Reference: (1) D. B. O. Savile. Fungi Can. 309:1, 1986. (2) M V Wiese. Compendium of Wheat Diseases. The American Phytopathological Society, St Paul, MN, 1987.

First Report of Puccinia sorghi on Maize in Oman.

Maize (Zea mays L.) is an important annual forage crop cultivated in the Sultanate of Oman, especially during the summer months. It is used for green fodder and grains and often intercropped in fruit orchards, especially under date palms. In April of 2005, leaf samples showing rust symptoms were collected from Samail, 100 km south of Muscat. Oval-shaped, red-brown pustules covered both sides of the leaves and yielded urediniospores typical of Puccinia sorghi Schwein. Urediniospores were roughly subglobose, measured 23 to 28 × 20 to 25 µm, echinulate, with three or four equitorial germ pores (2). Teliospores (38 to 42 × 16 to 19 µm) were observed, but few in numbers, most probably because of the time of year of collection. Pathogen identity was confirmed by nuclear ribosomal large subunit (28S) and internal transcribed spacer region 2 (ITS-2) DNA analysis (voucher sequence deposited in GenBank, Accession No. DQ345724, voucher specimen deposited in the U.S. National Fungus Collections, BPI 871134). P. sorghi has previously been reported from Yemen and Saudi Arabia (1) but not from Oman. Maize is grown throughout the year in Oman, and pathogen survival probably does not require the presence of the alternate host, nonetheless, Oxalis species are present and current research is attempting to locate and confirm the presence of the aecial stage in Oman. References: (1) CMI Distribution Maps of Plant Diseases. Map No. 279. Ed. 4. CABI, Wallingford, UK, 1978. (2) D. G. White, ed. Compendium of Corn Diseases. The American Phytopathological Society, St Paul, MN, 1999.

Calcium-G protein interactions in the regulation of macrophage secretion.

The interplay between activated G proteins and intracellular calcium ([Ca(2+)](i)) in the regulation of secretion was studied in the macrophage, coupling membrane capacitance with calcium-sensitive microfluorimetry. Intracellular elevation of either the nonhydrolyzable analogue of GTP, guanosine-5'-O-(3-thiotriphosphate) (GTP gamma S), or [Ca(2+)](i) enhanced the amplitude and shortened the time course of stimulus-induced secretion in a dose-dependent manner. Both the ionophore- and the stimulus-induced secretory response were abolished in the presence of guanosine-5'-O-(2-thiodiphosphate) (GDP beta S). The K(d) of Ca(2+)-driven secretion was independent of GTP gamma S concentration, whereas the K(d) of the GTP gamma S-driven response decreased from 63 to 31 microM in the presence of saturating concentrations of [Ca(2+)](i). The time course of stimulus-induced secretion was dependent upon the concentration of [Ca(2+)](i). The time course of GTP gamma S-driven secretion was concentration-independent at high levels of [Ca(2+)](i), suggesting that a calcium-dependent translocation/binding step was rate-limiting. Our data strongly support a model in which [Ca(2+)](i) and activated G proteins act independently of one another in the sequential regulation of macrophage secretion. [Ca(2+)](i) appears to play a role in the recruitment and priming of vesicles from reserve intracellular pools at a step that is upstream of G protein activation. While activated, G proteins appear to play a key role in fusion of docked vesicles. Thus, secretion can result either from activating more G proteins or from elevating [Ca(2+)](i) at basal levels of G protein activation.

Regulation of human CLC-3 channels by multifunctional Ca2+/calmodulin-dependent protein kinase.

The multifunctional calcium/calmodulin-dependent protein kinase II, CaMKII, has been shown to regulate chloride movement and cellular function in both excitable and non-excitable cells. We show that the plasma membrane expression of a member of the ClC family of Cl(-) channels, human CLC-3 (hCLC-3), a 90-kDa protein, is regulated by CaMKII. We cloned the full-length hCLC-3 gene from the human colonic tumor cell line T84, previously shown to express a CaMKII-activated Cl(-) conductance (I(Cl,CaMKII)), and transfected this gene into the mammalian epithelial cell line tsA, which lacks endogenous expression of I(Cl,CaMKII). Biotinylation experiments demonstrated plasma membrane expression of hCLC-3 in the stably transfected cells. In whole cell patch clamp experiments, autonomously active CaMKII was introduced into tsA cells stably transfected with hCLC-3 via the patch pipette. Cells transfected with the hCLC-3 gene showed a 22-fold increase in current density over cells expressing the vector alone. Kinase-dependent current expression was abolished in the presence of the autocamtide-2-related inhibitory peptide, a specific inhibitor of CaMKII. A mutation of glycine 280 to glutamic acid in the conserved motif in the putative pore region of the channel changed anion selectivity from I(-) > Cl(-) to Cl(-) > I(-). These results indicate that hCLC-3 encodes a Cl(-) channel that is regulated by CaMKII-dependent phosphorylation.

Oxidants potentiate Ca(2+)- and cAMP-stimulated Cl(-) secretion in intestinal epithelial T84 cells.

BACKGROUND & AIMS: Diarrhea is one of the major complications of inflammatory bowel disease. The role of oxidants in promoting net intestinal secretion is important, but the cellular mechanisms underlying their effects are unclear. We examined the effects and defined the cellular actions of the oxidant monochloramine (NH(2)Cl) on anion secretion in human colonic T84 cells. METHODS: Effects of NH(2)Cl on basal and agonist-stimulated short-circuit current (Isc) of T84 monolayers were determined. Apical Cl(-) and basolateral K(+) conductances were measured by efflux of (125)I(-) and (86)Rb(+), respectively. RESULTS: NH(2)Cl alone had little effect on Isc and (125)I(-) efflux. However, pretreatment with NH(2)Cl led to a concentration-dependent potentiation of the Ca(2+)-mediated Isc and of submaximal cAMP-mediated responses. These effects were associated with increased basolateral K(+) channel conductance and were blocked by increasing cellular Ca(2+) buffering capacity with Quin-2. Whole-cell voltage clamp experiments showed that NH(2)Cl potentiated Ca(2+) activation of basolateral K(+) channel conductance. CONCLUSIONS: Oxidants potentiate both Ca(2+)- and cAMP-stimulated Cl(-) secretion by a direct effect on calcium-activated basolateral K(+) channel conductance, lowering its Ca(2+) activation threshold. This effect may play an important role in amplifying and prolonging the secretory response of inflamed intestinal mucosa and enhancing the severity of diarrhea.

Impermeability of the GIRK2 weaver channel to divalent cations.

A single amino acid mutation (G156S) in the putative pore-forming region of the G protein-sensitive, inwardly rectifying K(+) channel subunit, GIRK2, renders the conductance constitutively active and nonselective for monovalent cations. The mutant channel subunit (GIRK2wv) causes the pleiotropic weaver disease in mice, which is characterized by the selective vulnerability of cerebellar granule cells and Purkinje cells, as well as dopaminergic neurons in the mesencephalon, to cell death. It has been proposed that divalent cation permeability through constitutively active GIRK2wv channels contributes to a rise in internal calcium in the GIRK2wv-expressing neurons, eventually leading to cell death. We carried out comparative studies of recombinant GIRK2wv channels expressed in Xenopus oocytes and COS-7 cells to determine the magnitude and relative permeability of the GIRK2wv conductance to Ca(2+). Data from these studies demonstrate that the properties of the expressed current differ in the two systems and that when recombinant GIRK2wv is expressed in mammalian cells it is impermeable to Ca(2+).

Syntaxin 1A is expressed in airway epithelial cells, where it modulates CFTR Cl(-) currents.

The CFTR Cl(-) channel controls salt and water transport across epithelial tissues. Previously, we showed that CFTR-mediated Cl(-) currents in the Xenopus oocyte expression system are inhibited by syntaxin 1A, a component of the membrane trafficking machinery. This negative modulation of CFTR function can be reversed by soluble syntaxin 1A peptides and by the syntaxin 1A binding protein, Munc-18. In the present study, we determined whether syntaxin 1A is expressed in native epithelial tissues that normally express CFTR and whether it modulates CFTR currents in these tissues. Using immunoblotting and immunofluorescence, we observed syntaxin 1A in native gut and airway epithelial tissues and showed that epithelial cells from these tissues express syntaxin 1A at >10-fold molar excess over CFTR. Syntaxin 1A is seen near the apical cell surfaces of human bronchial airway epithelium. Reagents that disrupt the CFTR-syntaxin 1A interaction, including soluble syntaxin 1A cytosolic domain and recombinant Munc-18, augmented cAMP-dependent CFTR Cl(-) currents by more than 2- to 4-fold in mouse tracheal epithelial cells and cells derived from human nasal polyps, but these reagents did not affect CaMK II-activated Cl(-) currents in these cells.

Pituitary prolactin-secreting tumor formation: recent developments.

Prolactinoma is the most common type of primary pituitary tumors. It occurs more frequently in women than in men. Dopaminergic agonists are effective in the shrinkage of prolactin-secreting pituitary tumor and are preferred in some patients. However, pituitary radiotherapy may enable the long-term removal of prolactin-secreting tumor cells. Recent evidence suggests that prolactinoma is a heterogeneous disorder with complicated and multifactorial etiology and pathogenesis. Apparently, a thorough understanding of prolactinoma tumorigenesis would be important. To facilitate investigations on tumorigenesis of prolactinoma, animal models for prolactinomas have been developed. These models have expedited our progress in the recent years. Many researchers consider the F(344) rat to be the most sensitive strain of rats to estrogen (E(2))-induced prolactinoma formation. Nonetheless, E(2) treatment for 60 days also induces the formation of pituitary prolactin-secreting adenoma in male Sprague-Dawley (SD) rats. Evidently, the SD rat is also a good animal for prolactinoma investigations. Following E(2) implantation, prolactinomas developed in the eutopic adenohypophysis in situ and/or ectopic pituitary grafted under the renal capsule in SD rats. These observations favor the hypothesis that prolactinoma growth is the result of pathological changes in the adenohypophysis and/or hypothalamus. In the latter case, abnormal release of hypothalamic dopamine, GABA, or brain-gut peptides (such as cholecystokinin, vasoactive intestinal polypeptide, galanin, angiotensin, opioid peptide, gastrin, gastrin-releasing peptide, pancreatic polypeptide, and adrenocorticotropic hormone) results in some of the pathological changes that may lead to hyperprolactinemia and/or prolactinoma development. Dysregulation of prolactin synthesis and secretion may be the result of prolactin gene modulation. In E(2)-induced rat prolactinomas, prolactin mRNA contents and the expression of some proto-oncogenes, e.g. c-myc and c-ras, TGFalpha and TGFbeta1 mRNA were significantly changed. The above findings are consistent with results in human prolactinoma development. In addition, in rats abnormal expression of the prolactin gene was correlated with hypomethylated status of CpG sites in exons 1, 2 and 4 of the prolactin gene, as well as the increase in hypersensitive sites to DNase 1 in the encoding region of the prolactin gene. In E(2)-treated rats, a point mutation with a base substitution from cytidine (C) to adenine (A) was found at the -36-bp site of the proximal promoter of the prolactin gene in eutopic pituitary prolactinomas, but no change was observed in the same sequence of the prolactin gene in ectopic prolactinoma. The association of a base substitution with the hyperexpression of the prolactin gene in eutopic prolactinomas suggests that different mechanisms may mediate the formation of eutopic and ectopic prolactin-secreting tumors. Melatonin decreases the expression of the prolactin gene in vitro suggesting that this pineal hormone may be a potential anticarcinogen in vivo. It has also been shown that MT(2) (Mel(1b)) melatonin receptors are expressed in anterior pituitary cells. The use of melatonin as a preventive or therapeutic drug for prolactinomas should be further investigated. In summary, improved knowledge on tumorigenesis of prolactinomas, especially in the rat model, was noted. These E(2)-induced rat prolactinoma models would facilitate future investigations, and expected results shall be fruitful and exciting for the development of future drug designs for the prevention and/or treatment of prolactin-secreting pituitary tumors.

[Effects of growth factors and estrogen on the proliferation and prolactin gene expression in anterior pituitary cells of rats].

OBJECTIVE: Detect the effects of exogenous 17 beta-estradiol (E2), epidermal growth factor (EGF), and transforming growth factor beta 1 (TGF beta 1) on the proliferation and prolactin (PRL) gene expression in primary serum-free cultured anterior pituitary cells in vitro. METHODS: Laser scanning confocal microscopy (LSCM) and in situ hybridization in primary serum-free cultures of rat anterior pituitary cells were employed. RESULTS: After 36 hours incubation of the monolayer with E2(10(-8) mol/L) and EGF(10(-8) mol/L), DNA and PRL mRNA contents in the cells were increased significantly (P < 0.001); and when cells were co-incubated with E2 and EGF at the same time, the levels of DNA and PRL mRNA were higher than those treated with E2 or EGF alone (P < 0.01), respectively. TGF beta 1(2 ng/ml) treatment decreased the DNA and PRL mRNA contents significantly (P < 0.001). Its inhibitory effect was reduced at the presence of E2, the DNA and PRL mRNA levels in the cells were higher than those treated with TGF beta 1 alone (P < 0.001), but still lower than E2 alone treatment (P < 0.001). CONCLUSIONS: The results indicate that EGF and TGF beta 1 exerte stimulatory inhibitory effects, on cell proliferation and PRL gene expression in anterior pituitary cells of rats in both basal and E2-induced conditions. EGF and TGF beta 1 may be involoved in the regulation of proliferation and PRL gene expression in anterior pituitary cells in vivo; and also may be correlated with prolactin-secreting tumors formation induced by E2.

[E2-induced prolactin-secreting tumor of heteroplasty pituitary in renal capsule of the rats].

OBJECTIVE: A prolactin-producing tumor induced by 17-beta-estradiol (E2) in isotransplanted pituitaries under renal capsules of SD rats were studied. METHODS: Male SD rats (30 days old) were transplanted with an isologaus pituitary under renal capsule and treated with subcutaneous implantation of an empty or E2-laden silastic capsule. RESULTS: After treated with E2 for 60 days and 120 days, both the eutopic and ectopic pituitaries were more than three times heavier than those from control rats, accompanied by hyperprolactinemia, and the body weight of rats decreased significantly. The effects of E2 on the weight of eutopic pituitary and the concentration of plasma PRL were time-dependent. In situ hybridization was employed to measure the levels of PRL mRNA expression in cells from the eutopic and ectopic pituitaries 120 days after treatment of E2. The PRL mRNA contents in both the eutopic and ectopic pituitary cells were much greater than those in untreated pituitary cells. But PRL mRNA levels showed no significant difference between the eutopic and ectopic pituitary cells. CONCLUSIONS: Our previous data has shown that prolactinomas can be induced by chronic treatment of E2 in eutopic pituitaries of SD rats. In present study it appeared that E2 exerted similar effect on the ectopic pituitaries which were distant from the hypothalamus. Our results also demonstrated that E2 could promote the PRL gene expression in both the eutopic and ectopic pituitary cells, and there was no significant difference between them. Our data suggested the possibility of PRL-producing pituitary tumors could originate from anterior pituitary.

[The effects of gastrin-releasing peptide (GRP) and vasoactive intestinal polypeptide (VIP) on the prolactin (PRL) gene transcription of pitutitary PRL releasing tumor of rat].

The effects of gastrin-releasing peptide (GRP) and vasoactive intestinal polypeptide (VIP) on the prolactin gene transcription of cultured pituitary of male Sprague-Dawley (SD) rats PRL releasing tumor (PPRT) (induced by estradiol) cells were studied. The PRL mRNA levels were determined by in situ hybridization of cytoplasmic RNA with a DIG-labeled PRL cDNA probe. PRL mRNA levels didn't change when the PPRT cells were incubated with 10(-8) mol/L or 10(-7) mol/L GRP for 24 h, but decreased by 20% when GRP was increased to 10(-6) mol/L (P < 0.05). The PRL mRNA level increased to 1.60, 2.10, 2.21 times of the control group when the PPRT cells were respectively incubated with 10(-8), 10(-7), 10(-6) mol/L VIP for 24 h (P < 0.05). The PRL mRNA level didn't change when the PPRT tumor cells were incubated with 10(-8) mol/L E2 for 48 h, but did increase to 2.80 and 2.92 times of the control group respectively when 10(-7) mol/L and 10(-6) mol/L E2 were used. The results above indicated that GRP and VIP exert an inhibitory and a stimulatory effect on RPL gene transcription respectively, while the stimulatory action of E2 on PRL secretion is a direct one.

[The effects of E2 and it's metabolites on the proliferation of rat anterior pituitary cells in vitro].

OBJECTIVE AND METHODS: The present work is determined to observe the effects of E2 (estradiol), 2-OHE1 (2-hydroxyestrone), 2-OHE2 (2-hydroxyestrodiol) on the proliferation of rat anterior pituitary cells (APC) in vitro by laser scanning confocal microscopy. RESULTS: 10(-6) mol/L E2 stimulated the growth of APC. After 2 days of incubation with E2, the DNA content of APC increased to 1.3 times of the control group (P < 0.01). 10(-6) mol/L 2-OHE2 (other than 2-OHE1) stimulated proliferative activity of APC and inhibited the inhibitory effect of peribidil (10(-5) mol/L), a dopamine receptor agonist, on the poliferative activity of rat APC.

[Melatonin inhibits TRH-stimulating prolactin gene expression of anterior pituitary cells in newborn rat in vitro].

OBJECTIVE AND METHODS: This work was to investigate whether melatonin (MEL) plays a role in the gene expression of prolactin (PRL), by the Method of in situ hybridyzation. RESULTS: Our results indicated that, at a higher concentration, MEL not only inhibits TRH (thyrotropin releasing hormone) stimulating PRL gene expression of anterior pituitary cell in newborn rat, but also exerts a direct inhibitory effect on PRL gene expression in vitro. CONCLUSION: These results suggest that MEL may be a regulator of PRL synthesis and secreting in vivo.