Acute and Subacute Effect of LH-RH upon LH-and FSH-Gonadotrophs in Castrated Female Rats with Short-Term Estrogen-Progesterone Pretreatment

Soji, Tśuyoshi; Taya, Kazuyoshi; Igarashi, Masao; Yoshimura, Fujio

doi:10.1507/endocrj1954.21.407

Cited by 7 publications

(9 citation statements)

References 13 publications

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“…We have often observed that the LH‐RH did not elicit a consistent response from all gonadotrophs. After the treatment of pharmacological doses of the GnRH (100 ng/rat), we found by ultrastructural analysis that a variety of gonadotrophs discharged their secretory granules while others remained impregnated with granules suggesting that the hormone had a limited effect on LH release (Soji et al, 1974). These phenomena were often observed in vitro that the LH release from gonadotrophs was different in response to LH‐RH pulses of various duration and different concentrations in the presence and absence of external Ca ++ (Blum et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

Intercellular communication within the rat anterior pituitary gland: X. Immunohistocytochemistry of S‐100 and connexin 43 of folliculo‐stellate cells in the rat anterior pituitary gland

et al. 2004

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Since Rinehart and Farquhar reported the presence of agranulated cells in the anterior pituitary gland in 1953, the functions of the folliculo-stellate cell remain to be clarified. Intercellular junctions have been described in the monkey, rat, and teleost anterior pituitary glands, indicating the existence of cell-to-cell communication within the organ. We pointed to their possible role in the rapid dissemination of information through a complex interconnecting system of follicles involving gap junctions. The gap junctional/folliculo-stellate cellular network was essential in the maturation and regulation of the pituitary gland system such as the hypothalamic-pituitary-gonadal axis. It has been was shown that a network participated in the conduction of electrophysiological information over a long distance using the ion Ca ϩϩ , which propagates to other folliculo-stellate cells by signaling through gap junctions. Sixty-day-old male rats were used in this study for light microscopic immunohistochemistry of S-100 protein, type I collagen, and connexin 43, and for electron microscopy to observe the morphological relationships between the cellular networks of folliculo-stellate cells and granulated pituitary cells. Clusters of anti-S-100 protein-positive cells were clearly observed in a region of the hypophysis tentatively named the transition zone. Anti-S-100 protein-positive cells and their cytoplasmic processes were also present in the anterior lobe and assembled together to form follicular lumina. Type I collagen was clearly shown outlining the incomplete lobular or ductule-like structure making cell cords in the anterior pituitary gland. Numerous microvilli were present within the follicular lumen while around the lumina, junctional specializations including gap junctions were positive for the connexin 43 protein. A nonuniform distribution of the connexin 43-positive sites were observed. Small or dot-shaped positive sites were noted where two clusters of cells were connected; the cells were identified as S-100 cells. Double immunohistochemical staining of the connexin 43 and growth hormone (GH) or connexin 43 and luteinizing hormone (LH) was also performed, demonstrating no direct relationship between the connexin 43 and either the GH or LH cells. These findings indicate that there are two kinds of messages necessary for the hormone release in the pituitary gland. One is via the portal vein system, the other is through the gap junction-mediated networks of folliculo-stellate cells. The granulated cells directly associate with cell membrane of folliculo-stellate cells are able to discharge secretory granules through communication via gap junctions, while those granulated cells that are more distant from the folliculo-stellate cells are only able to discharge hormones via the pituitary hormone-releasing hormone from the portal vein system. Anat Rec Part A 278A: 462-473, 2004.

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Section: Discussionmentioning

confidence: 99%

Intercellular communication within the rat anterior pituitary gland: X. Immunohistocytochemistry of S‐100 and connexin 43 of folliculo‐stellate cells in the rat anterior pituitary gland

et al. 2004

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“…Regarding this speculation, the velocity of the secretory cycle as well as the population of the synchronized cells may serve as a key point for consideration. The shortest duration time necessary for the performance of one secretory cycle was tentatively estimated about 180min, when the appropriate dose of TRH or LRH was injected intravensously (Yoshimura et al, 1974a and b;Soji et al, 1974). It was postulated that the chronic subcutaneous injections could enhance the rotation of each secretory cycle not always synchronized over the basophils.…”

Section: Discussionmentioning

confidence: 99%

“…In our preceding papers (Yoshimura et al, 1974a and b;Soji et al, 1974), however, quite different opinions as to the target cell of LRH through their acute or subacute experiment were reported.…”

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confidence: 95%

Chronic effect of TRH and LRH upon a series of basophils along with the serum and pituitary TSH, LH and FSH concentration.

et al. 1977

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“…, , , Shiino et al (1972), Schally et al(1972) ;Moriarty, 1975 andSOJI 1976;Moriarty and Tobin, 1976). Our previous experiments on the acute and chronic effect of TRH and LRH indicated that these hormones did not act independently on the release of their corresponding releasing hormones (Yoshimura et al, 1973 andSoji et al, 1974 and1977). It was morphologically evidenced by Soji et al(1977) that one releasing hormone not only acted upon its corresponding target cell to release the secretory granules, but also upon the other kinds of basophils.…”

mentioning

confidence: 98%

Acute and Subacute Effect of LH-RH upon LH-and FSH-Gonadotrophs in Castrated Female Rats with Short-Term Estrogen-Progesterone Pretreatment

Cited by 7 publications

References 13 publications

Intercellular communication within the rat anterior pituitary gland: X. Immunohistocytochemistry of S‐100 and connexin 43 of folliculo‐stellate cells in the rat anterior pituitary gland

Intercellular communication within the rat anterior pituitary gland: X. Immunohistocytochemistry of S‐100 and connexin 43 of folliculo‐stellate cells in the rat anterior pituitary gland

Chronic effect of TRH and LRH upon a series of basophils along with the serum and pituitary TSH, LH and FSH concentration.

Changes of serum and pituitary TSH, LH and FSH concentrations following the slow infusion of TRH and LRH.

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