• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.269-275
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• 1996

Biosynthesis and secretion of anterior pituitary hormones are under the control of specific hypothalamic stimulatory and inhibitory factors. Among them, Growth Hormone Releasing Hormone (GHRH) is the major stimulator of pituitary somatotrophs activating GH gene expression and secretion. Human GHRH is a polypeptide of 44 amino acids initially isolated from pancreatic tumors, and the gene for the hypothalamic form of GHRH is organized into 5 exons spanning over 10 kilobases (kb) on genomic DNA and encodes a messenger RNA of 700-750 nucleotides. Several neuropeptides classically associated with the hypothalamus have been found in the extrahypothalamic regions, suggesting the existence of novel sources, targets and functions. GHRH-like immunoreactivity has been found in several peripheral sites, including placenta, testis, and ovary, indicating that GHRH may also have regulatory roles in peripheral reproductive organs. Furthermore, higher molecular weight forms of the GHRH transcripts were identified from these organs (1.75 kb in testis; 1.75 and >3 kb in ovary). These tissue-specific expression of GHRH gene suggest the existence of unique regulatory mechanism of GHRH expression and function in these organs. In fact, placenta-specific and testis-specific promoters for GHRH transcripts which are located in about 10 kb upstream region of hypothalamic promoter were reported. The use of unique promoters in extrahypothalamic sites could be refered in a different control of GHRH gene and different functions of the translated products in these tissues. Somatotrophs and lactotrophs have been thought to be derived from a common bipotential progenitor, the somatolactotrophs, which give origins to either phenotypes. Although the precise mechanism responsible for the lactotroph differentiation in the anterior pituitary gland has not been yet clalified, there are several candidators for the generation of lactotrophs. In human, the presence of GHRH peptides with different size from authentic hypothalamic form in the normal anterior pituitary and several types of adenoma were demonstrated. Recently our group found the existence of immunoreactive GHRH and its transcript from the normal rat anterior pituitary (gonadotroph> somatotroph> lactotroph), and the GHRH treatment evoked the increased proliferation rate of anterior pituitary cells in vitro. The transgenic mouse models clearly shown that GHRH or NGF overexpression by anterior pituitary cells induced development of pituitary hyperplasia and adenomas particularly GH-oma and prolactinoma. Taken together, we hypothesize that the pituitary GHRH could serve not only as a modulator of hormone secretion but as a paracrine or autocrine regulator of anterior pituitary cell proliferation and differentiation. Interestingly enough, the expression of Pit-1 homeobox gene (the POU class transcription factor) was confined to somatotrophs, lactotrophs and somatolactotrophs in which GHRH receptors are expressed commonly. Concerning the mechanism of somatolactotroph and lactotroph differentiation in the anterior pituitary, we have focused following two possibilities; (1) changes in the relative levels or interactions of both hypothalamic and intrapituitary factors such as dopamine, VIP, somatostatin, NGF and GHRH; (2) alterations of GHRH-GHRH receptor signaling and Pit-1 activity may be the cause of lactotroph differentiation or pituitary hyperplasia and adenoma formation. Extensive further studies will be necessary to solve these complicated questions.

• Development and Reproduction
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• v.4 no.2
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• pp.237-242
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• 2000

Growth hormone releasing hormone (GHRH), the major hypothalamic stimulus of GH secretion from the anterior pituitary gland, has been found to be present in several extrahypothalamic sites including placenta testis, ovary and anterior pituitary gland. The present study was performed to elucidate the role of pituitary GHRH on proliferation of cells derived from rat anterior pituitary gland. The GHRH content of pituitary tissue, cultured pituitary cells, and the conditioned media was evaluated by radioimmunoassay (RIA). Primary cultures of pituitary cells derived from adult rats were prepared by enzymatic dispersion. Significant amounts of GHRH-like molecules were detected in both pituitary tissue and cell cultures by GHRH RIA. Competition curves with increasing amounts of tissue extracts and conditioned media were parallel with those of standard peptide, indicating that the pituitary GHRH-like material is similar to authentic GHRH. To analyze specific cell types responsible for producing GHRH in anteroior pituitary, cell fractionation technique combined with GHRH RIA was performed. In cell fractionation experiment, the highest level of GHRH content was found in gonadotrope enriched-fraction and followed by somatotrope-, lactotrope- and thyrotrope-fraction. Treatment of pituitary cells with GHRH resulted in a dose-dependent increase in [$^3$H] thymidine incorporation. The mitogenic effect of GHRH could be mediated by typical oncogenic activation since the GHRH induced transient increase in c-fos mRNA levels with peak response at 30 minutes. The present study demonstrated that i) the pituitary GHRH expressed in the rat anterior pituitary gland can be secreted, ii) among the various cell types, gonadotropes and somatotorpes are the major GHRH source, and iii) the GHRH treatment increased the [$^3$H] thymidine incorporation and c-fos transcriptional activity in the pituitary cell culture. These findings suggested that GHRH could participated in the paracrine and/or autocrine regulation of cell proliferation, as well as promoting growth hormone secretion.

• Korean Journal of Pharmacognosy
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• v.9 no.1
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• pp.33-39
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• 1978

The present study is involved with the prolactin secretion from anterior pituitary gland by ginseng saponin since it was handled down by tradition that ginseng might influence the milk secretion when it was given to nursing mother. To investigate the effect of saponin on the prolactin production or release from the anterior pituitary gland, cell culture study and whole animal studies were carried out. For the cell culture study, enzymatically dispersed anterior pituitary cells of rat anterior pituitary gland in HEPES buffers containing trypsin were used. Ginseng saponin was added to the culture media and the amount of prolactin produced in the cell culture media was determined by radloimmunoassay(RIA) technique. Dose-dependent increases of prolactin with ginseng saponin were observed, whereas, no change was observed without ginseng treatment. For the whole animal study, normal and castrated rats which previously cannulated into the heart via the right juglar vein were used. The prolactin concentration in plasma were determined by using the technique of RIA. In normal rats, prolactin concentration in plasma were elevated dramatically after 1 hour of ginseng saponin administration, whereas, instantaneous increases were observed in castrated rats. For prolactin assay by RIA, NIAMDD Rat Prolactin Kit and NIAMDD Rat Prolactin RP-1 were used as standard. The results indicate that ginseng saponins increase the release of prolactin from the anterior pituitary gland and production of prolactin from the cell in rats.

• Archives of Pharmacal Research
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• v.3 no.2
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• pp.85-86
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• 1980

Dopaminergic influences on prolactin release from lactotrophs have been studied using the rat anterior pituitary cell culture. The prolactin inhibiting activity of hypothalamic extracts was examined in relation to dopamine. Dopamine inhibited prolactin secretion from the rat anterior pituitary cell culture in a dose dependent fashion. The median effective dose was $2{\times}10^{-7}$ / M and the maximal inhibition (70-90 % of the control value) was shown by 10$^{-5}$ / M dopamine. Further increase in dopamine concentration did not result in any further inhibition of prolactin secretion.nhibition of prolactin secretion.

• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.42-47
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• 2010

Objective: To investigate the morphometric characteristics of the pituitary gland and diaphragma sellae in Korean adults. Methods: Using the 33 formaline fixed adult cadavers (23 male, 10 female), the measurements were taken at the diaphragma sellae and pituitary gland. The authors investigated the relationship between dura and structures surrounding pituitary gland, morphometric aspects of pituitary gland and stalk, and morphometric aspect of central opening of diaphragma sellae. Results: The boundary between the lateral surface of pituitary gland and the medial wall of cavernous sinus was formed by the thin dural layer and pituitary capsule. The pituitary capsule adherent tightly to the pituitary gland was observed to continue from the diaphragma sellae. Mean width, length, and height of the pituitary gland were 14.3${\pm}$2.1, 7.9${\pm}$1.3, and 6.0${\pm}$0.9 mm in anterior lobes, and 8.7${\pm}$1.7, 2.9${\pm}$1.1, and 5.8${\pm}$1.0 mm in posterior lobes, respectively. Although all dimensions of anterior lobe in female were slightly larger than those in male, statistical significance was noted in only longitudinal dimension. The ratio of posterior lobe to the whole length of pituitary gland was about 27%. The mean thickness of pituitary stalk was 2 mm. The diaphragmal opening was 5 mm or more in 26 (78.8%) of 33 specimen. The opening was round in 60.6% of the specimen, and elliptical oriented in an anterior-posterior or transverse direction in 39.4%. Conclusion: These results provide the safe anatomical knowledge during the transsphenoidal surgery and may be helpful to access the possibility of the development of empty sella syndrome.

• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1130-1133
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• 2001

Athke's cleft cysts are believed to be derived from remnants of Rathke's pouch, a dorsal invagination of the stomodeum. Although these cysts are characteristically small, asymptomatic and intrasellar in location, they occasionally provoke symtoms with enlargement to compress surrounding structures. It is characteristically lined by stratified squamous epithelium with keratinization on a layer of connective tissue. The cells of the anterior pituitary lobe, from which pituitary adenomas develop, are also formed by the proliferation of the anterior wall of Rathke's pouch. Thus, Rathke's cleft cyst and pituitary adenomas are considered to have a common ancestry. We report a rare case in which the preoperative diagnosis was pituitary adenoma, but the pathologic diagnosis was a combination of a Rathke's cleft cyst and a coincidental pituitary adenoma.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.591-597
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• 2022

Objective : Pituitary adenomas frequently extend into the suprasellar space. After a suprasellar tumor is removed, the superiorly extended arachnoid becomes redundant and sinks down into the intrasellar space which often hiders visualization and accessibility to the hidden space behind the evaginated arachnoid. We introduced arachnoid remodeling by clipping technique, and evaluated its usefulness and safety during TSS. Methods : Total 223 patients who underwent arachnoid remodeling with our new clipping technique were included. Redundant arachnoid was clipped along the dural edge with multiple 2.6-mm titanium clips until the redundant arachnoid membrane no longer blocked the surgical route. To check for possible deterioration of hormonal function by this technique, we assessed anterior pituitary function of 166 patients who underwent arachnoid remodeling by clipping and compared this with those of other 429 control patients. Results : Our technique greatly enhanced the accessibility and visualization of intrasellar and parasellar spaces, both of which are generally hindered by redundant arachnoid during transsphenoidal surgery (TSS). We found no difference in anterior pituitary function between a clip-assisted arachnoid remodeling group and the control group, implying that this technique does not result in hypopituitarism. Conclusion : During TSS for pituitary adenomas with suprasellar extension, arachnoid remodeling by clipping technique is very useful and convenient for the management of the redundant arachnoid membrane to enhance visualization and surgical accessibility.

• Development and Reproduction
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• v.2 no.2
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• pp.189-196
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• 1998

Several lines of evidence indicate that some neuropeptides classically associated hypothalamus have been found in pituitary gland, suggesting the existence of local regulation of pituitary function. Among the hypothalamic releasing hormones, genes for TRH and GnRH are expressed in the rat anterior pituitary gland. The present study was carried out to investigate the expression of the GHRH gene in rat anterior pituitary and the pituitary-derived cell lines. The presence of GHRH transcripts in pituitary tissue was shown by 3'rapid amplification of cDNA end (3'-RACE) analysis. In reverse transcription-polymerase chain reaction (RT-PCR) study, GHRH cDNA fragments were amplified from two pituitary-derived cell lines, $\alpha$T3 cells originated from mouse gonadotrope and GH3 cells from rat somatolactotrope. Immunoreactive GHRH was detected in large and medium-sized pituitary cells by immunocytochemistry. Significant amounts of GHRH-like molecules were found in the GH3 cell extracts. In RNase protection assay, the level of pituitary GHRH mRNA was augmented by ovariectomy. These results demonstrate that GHRH gene is expressed in the rat gonadotropes and somatotropes, and suggest that the pituitary GHRH could be participated in the paracrine and/or autocrine regulation of cell proliferation, as well as promoting growth hormone secretion.

• Journal of Korean Neurosurgical Society
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• v.45 no.2
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• pp.118-121
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• 2009

Pituitary apoplexy is a clinical syndrome caused by an acute ischemic or hemorrhagic vascular accident involving a pituitary adenoma or an adjacent pituitary gland. Pituitary apoplexy may be associated with a variety of neurological and endocrinological signs and symptoms. However, isolated third cranial nerve palsy with ptosis as the presenting sign of pituitary apoplexy is very rare. We describe two cases of pituitary apoplexy presenting as sudden-onset unilateral ptosis and diplopia. In one case, brain magnetic resonance imaging (MRI) revealed a mass in the pituitary fossa with signs of hemorrhage, upward displacement of the optic chiasm, erosion of the sellar floor and invasion of the right cavernous sinus. In the other case, MRI showed a large area of insufficient enhancement in the anterior pituitary consistent with pituitary infarction or Sheehan's syndrome. We performed neurosurgical decompression via a transsphenoidal approach. Both patients showed an uneventful recovery. Both cases of isolated third cranial nerve palsy with ptosis completely resolved during the early postoperative period. We suggest that pituitary apoplexy should be included in the differential diagnosis of patients presenting with isolated third cranial nerve palsy with ptosis and that prompt neurosurgical decompression should be considered for the preservation of third cranial nerve function.

• The Journal of Pediatrics of Korean Medicine
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• v.15 no.1
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• pp.105-115
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• 2001

The relation of endocrine in the western medicine and zangfu-organ functions in Korean medicine, related to growth disturbance, was studied and derived the following results. 1. The hormone most related to growth disturbance is, directly secreted from the anterior pituitary or is stimulated and secreted in the target grands, growth hormone, thyroid, adrenocortical hormone, gonadial hormone and is insulin secreted from $\beta$ cell of langerhans' slands of pancreas. 2. the pituitary has the most close relation with the kidney in the five zang-organ. Because the kidney is innate origin(先天之本) and promotes qi and blood(生化氣血), stores the essence of life(藏精), dominates the bones(主骨) and promotes the marrow(生骨髓). Especially it is connected with brain(通於腦). 3. In the children growth, the endocrine action in the pituitary has the most close relation with the kidney, As in the reports of the brain and spinal cord, bone, store essence of life, sexual maturation and decline(kidney-qi, sexual functions of both sexes(天癸)) etc, and cause of cretinism, dwarf in the main subject. 4. Somatomedin is the most important factor of the growth factors, IGF in another word. The unification of IGF and secretion is controlled firstly according to growth hormone, however is very closely related to the nutrition status in the non-hormonic causes. Also, it is affected very much by the insulin. 5. Insulin is one of the important hormone related to the growth and is secreted from the pancreas. Pancreas belongs to the functional system of spleen in oriental medicine, thus the growth disturbance, occurred due to error in insulin secretion and nutrition(in another words, the lack of postnatal essential substance from food-stuff(水穀精氣)), is closely related to the spleen. 6. From the results driven above, the hormone action of endocrine and problem in secretion, related to the growth disturbance, must be focused on the differentiation of symptoms and signs of the kidney and the spleen in oriental medicine.