PERFUSION OF INTERCELLULAR SPACES IN THE PARS DISTALIS AND THEIR VARIATION WITH TIME OF DAY

1975 ◽  
Vol 66 (3) ◽  
pp. 385-NP
Author(s):  
W. B. QUAY
Keyword(s):  
Pituitary Gland ◽  
Functional Significance ◽  
Time Of Day ◽  
Male Rats ◽  
Pars Distalis ◽  
Intercellular Spaces ◽  
India Ink ◽  
Structural Regularity ◽  
Rat Pituitary ◽  
Light Darkness

SUMMARY Microperfusion of the tissue parenchyma of regions of the rat pituitary gland with 1:1 dilutions of India ink revealed a network of fine intercellular spaces or canaliculi throughout the pars distalis. They were demonstrable in animals of all ages from 1·5 months to over 1 year, in both sexes, and at various times during the 24 h light–darkness cycle. However, 24 h rhythms were suggested in the radial perfusion distance (P < 0·05) and tissue density (P < 0·01) of the perfused canaliculi in adult male rats. The amplitude of the 24 h rhythmicity in these pituitary canaliculi was lower than that shown recently in pineal canaliculi of the same species. Structural regularity and evidence of rhythmic and physiologically correlated changes in the pituitary canaliculi suggest that they relate to natural features rather than being only artifactual, and that analysis of their possible functional significance is appropriate.

ADRENOCORTICOTROPHIC HORMONE IN THE ANTERIOR AND NEUROINTERMEDIATE LOBES OF THE FETAL RAT PITUITARY GLAND

1981 ◽  
Vol 89 (2) ◽  
pp. 181-186 ◽  
Author(s):  
ALAIN CHATELAIN ◽  
J. P. DUPOUY
Keyword(s):  
Pituitary Gland ◽  
Functional Differentiation ◽  
Pars Intermedia ◽  
Adrenocorticotrophic Hormone ◽  
Pars Distalis ◽  
Adult Rats ◽  
Adrenal Cells ◽  
Specific Radioimmunoassay ◽  
Fetal Rat ◽  
Rat Pituitary

The concentration of ACTH in the pars distalis and pars intermedia of the fetal rat hypophysis from days 17–21 of pregnancy was measured with a specific radioimmunoassay and a bioassay using isolated adrenal cells from adult rats. In both lobes of the pituitary gland, a significant correlation was observed between immunoreactive and bioreactive values, expressed as pg equivalents synthetic human 1–39 ACTH per μg protein. In the pars distalis, ACTH concentrations increased steadily from days 17–20 and then remained unchanged to term. At this time they were tenfold higher than on day 17. In the neurointermediate lobe, ACTH was detected only from day 18; the concentration of ACTH increasing between days 18 and 19. At each of the stages of pregnancy examined, the concentration of ACTH in the pars distalis was greater than that in the pars intermedia. These data have demonstrated that ACTH is present in both anterior and neurointermediate lobes of the fetal rat hypophysis, that the functional differentiation of the pars distalis takes place earlier than that of the pars intermedia, and that the concentrations of corticotrophin in the pars distalis and in the pars intermedia have different patterns of development as gestation progresses.

Proliferation and differentiation of thyrotrophs in the pars distalis of the rat pituitary gland during the fetal and postnatal period

2001 ◽  
Vol 203 (4) ◽  
pp. 249-253 ◽  
Author(s):  
Y. Taniguchi ◽  
Satoru Yasutaka ◽  
Rieko Kominami ◽  
Harumichi Shinohara
Keyword(s):  
Pituitary Gland ◽  
Postnatal Period ◽  
Pars Distalis ◽  
Rat Pituitary ◽  
Proliferation And Differentiation

Regulation of the TRH-like peptide pyroglutamyl-glutamyl-prolineamide in the rat anterior pituitary gland

1995 ◽  
Vol 145 (1) ◽  
pp. 43-49 ◽  
Author(s):  
J M M Rondeel ◽  
W Klootwijk ◽  
E Linkels ◽  
G A C van Haasteren ◽  
W J de Greef ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Sex Difference ◽  
Anterior Pituitary ◽  
Biological Significance ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Anterior Pituitary Gland ◽  
Female Rats ◽  
Male Rats ◽  
Rat Pituitary

Abstract TRH-like peptides share the N- and C-terminal amino acids with TRH (pGlu-His-Pro-NH2) but differ in the middle amino acid residue. One of them, pGlu-Glu-Pro-NH2 (<EEP-NH2; EEP) is present in the rat pituitary gland, but its biological significance is unknown. We investigated the localization and regulation of this tripeptide in the rat pituitary gland. To distinguish between TRH and EEP two antisera were used for RIA: specificity of antiserum 4319 for the TRH-like peptides pGlu-Phe-Pro-NH2 and EEP was equal to or greater than that for TRH, whereas antiserum 8880 is TRH-specific. Our RIA data showed the presence of a TRH-like peptide in the anterior pituitary gland (AP) and of TRH in the posterior pituitary gland (PP). The TRH-like peptide in the AP was identified on anion-exchange chromatography and subsequent HPLC as EEP. Pathophysiological conditions such as altered thyroid and adrenal status and suckling did not affect pituitary gland levels of EEP. In general, however, there is a clear sex difference: levels of EEP are higher in male than in female rats. In both sexes gonadectomy leads to a substantial two- to threefold rise in EEP levels, abolishing the sex difference. Testosterone administration to gonadectomized male rats normalizes levels of EEP again. Disulfiram, an inhibitor of the enzyme peptidylglycine α-amidating monooxygenase, reduced levels of EEP in the AP by approximately 50%. In conclusion: 1) the TRH-like peptide EEP is present in the AP, whereas TRH is confined to the PP, 2) levels of EEP in the AP are regulated by sex steroids, 3) EEP is actively amidated in the AP and thus seems to be produced from a glycine-extended progenitor sequence. Journal of Endocrinology (1995) 145, 43–49

DIRECT ANTIPROLIFERATIVE EFFECT OF DOPAMINE AGONISTS ON THE ANTERIOR PITUITARY GLAND IN ORGAN CULTURE

1978 ◽  
Vol 79 (2) ◽  
pp. 245-246 ◽  
Author(s):  
M. PAWLIKOWSKI ◽  
J. KUNERT-RADEK ◽  
H. STĘPIEŃ
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Mitotic Activity ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Antiproliferative Effect ◽  
Male Rats ◽  
Pars Intermedia ◽  
Pituitary Tumours ◽  
Rat Pituitary

Department of Experimental Endocrinology, Institute of Endocrinology, Medical Academy of Łódź, Dr Sterling sir. 3, 91–425 Łódź, Poland (Received 22 May 1978) Lloyd, Meares & Jacobi (1975) observed inhibition of mitotic activity in the anterior pituitary gland by the dopamine receptor agonist, bromocriptine, in oestrogen-treated male rats. This observation has been confirmed in our laboratory (Stępień, Wolaniuk & Pawlikowski, 1978). Suppression of mitotic activity in the pars intermedia of the rat pituitary gland by bromocriptine has also been observed (Rychter & Stępień, 1977). Furthermore, it has been found that the dopamine receptor blocker, pimozide, enhances mitotic activity in the rat anterior pituitary gland (Stępień et al. 1978). By the use of various ergot alkaloids, MacLeod & Lehmeyer (1973) succeeded in inhibiting the growth of transplantable rat pituitary tumours. There have also been observations suggesting an antiproliferative effect of bromocriptine on human pituitary tumours (Wass, Thorner, Morris, Rees, Mason, Jones &

scholarly journals Estrogen Receptors are Involved in Xenoestrogen Induction of Growth Hormone in the Rat Pituitary Gland

2009 ◽  
Vol 55 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Vu Hoang DANG ◽  
Kyung-Chul CHOI ◽  
Eui-Bae JEUNG
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Estrogen Receptors ◽  
Rat Pituitary

scholarly journals CircAgtpbp1 Acts as a Molecular Sponge of miR-543-5p to Regulate the Secretion of GH in Rat Pituitary Cells

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 558
Author(s):  
ZeWen Yu ◽  
WenZhi Ren ◽  
Tian Wang ◽  
WeiDi Zhang ◽  
ChangJiang Wang ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Inhibitory Effect ◽  
Pituitary Cells ◽  
Sequencing Analysis ◽  
Hormone Regulation ◽  
Gh Secretion ◽  
Qrt Pcr ◽  
Rat Pituitary ◽  
Rat Pituitary Cells

CircRNAs have been identified to be expressed differently and stably in numerous species and tissues, but their functions in growth hormone (GH) secretion are still largely unknown. In summary, we have revealed a circRNA-miRNA-mRNA network that may play a biological role in the rat pituitary gland. First, we verified the chromosome location information of circAgtpbp1 according to sequencing analysis. The circAgtpbp1 characteristics were authenticated through PCR, qRT–PCR, treating with RNase and fluorescent in situ hybridization (FISH). Second, we detected the expression pattern of circAgtpbp1 in the rat anterior pituitary by qRT–PCR. We also designed circAgtpbp1 siRNA and constructed overexpression plasmid to evaluate the effect of circAgtpbp1 function on GH secretion by qRT–PCR, ELISA and Western blot. CircAgtpbp1 is a stable, truly circular molecule. We found that circAgtpbp1 interacted with miR-543-5p and can regulate GH secretion in pituitary cells through a circAgtpbp1-miR-543-5p-GH axis. Overall, the evidence generated by our study suggests that circAgtpbp1 can act as a sponge of miR-543-5p to reduce the inhibitory effect of miR-543-5p on Gh1 and further promote GH secretion. These findings expand our existing knowledge on the mechanisms of hormone regulation in the pituitary gland.

Synaptophysin Immunoreactivity in the Aging Rat Pituitary Gland

1997 ◽  
Vol 43 (6) ◽  
pp. 561-564 ◽  
Author(s):  
L.C Saland ◽  
A Apodaca ◽  
D Ramirez ◽  
V Hernandez ◽  
J Gaddy ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Rat Pituitary ◽  
Aging Rat

DISTRIBUTION OF NEUROSECRETORY GRANULES AMONG THE ANATOMICAL COMPARTMENTS OF THE NEUROSECRETORY PROCESSES OF THE PITUITARY GLAND: A QUANTITATIVE ULTRASTRUCTURAL APPROACH TO HORMONE STORAGE IN THE NEURAL LOBE

1976 ◽  
Vol 68 (2) ◽  
pp. 225-NP ◽  
Author(s):  
J. F. MORRIS
Keyword(s):  
Basement Membrane ◽  
Pituitary Gland ◽  
Neurosecretory Granules ◽  
Neural Lobe ◽  
Releasable Pool ◽  
Readily Releasable Pool ◽  
Rat Pituitary ◽  
Axonal Swellings ◽  
Granule Release

SUMMARY The distribution of neurosecretory granules in various anatomical compartments of neurosecretory axons of the neural lobe of the rat pituitary has been studied. Apart from the most anterior tip of the gland, where granules are largely restricted to undilated axons and a few 'swellings', the proportional compartmental storage of granules is essentially homogeneous for the rest of the gland: 13% of granules are found in undilated axons, 31% in axonal 'endings' (which contain microvesicles and abut the basement membrane) and 55% in axonal 'swellings' (which are devoid of significant numbers of microvesicles). These values indicate that the 'endings' contain a much greater proportion of the total number of granules stored in the neural lobe than would be predicted if the readily releasable pool of hormone were composed of all the granules in the 'endings'. Some further constraint on granule release either physiological or anatomical (e.g. the position of the granule in relation to the plasmalemma of the 'ending') must be operative.

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