scholarly journals Long-Lasting Intrinsic Optical Changes Observed in the Neurointermediate Lobe of the Mouse Pituitary Reflect Volume Changes in Cells of the Pars Intermedia

2010 ◽  
Vol 92 (3) ◽  
pp. 158-167 ◽  
Author(s):  
P. Kosterin ◽  
A.L. Obaid ◽  
B.M. Salzberg
Keyword(s):  
Pars Intermedia ◽  
Volume Changes ◽  
Neurointermediate Lobe ◽  
Mouse Pituitary ◽  
In Cells

The functional significance of glycosylation of proopiomelanocortin in melanotrophs of the mouse pituitary gland

1985 ◽  
Vol 107 (3) ◽  
pp. 365-374 ◽  
Author(s):  
B. G. Jenks ◽  
A. G. H. Ederveen ◽  
J. H. M. Feyen ◽  
A. P. van Overbeeke
Keyword(s):  
Pituitary Gland ◽  
Functional Significance ◽  
Peptide Hormones ◽  
Terminal Region ◽  
Pars Intermedia ◽  
Apparent Effect ◽  
Glycoprotein Precursor ◽  
Tunicamycin Treatment ◽  
Mouse Pituitary

ABSTRACT Pro-opiomelanocortin (POMC) is a glycoprotein precursor for a number of neuropeptides and peptide hormones. The functional significance of the glycosylation of POMC has never been established. Using the antibiotic tunicamycin to block glycosylation of the prohormone in the mouse pars intermedia, we have compared processing of non-glycosylated prohormone with that of glycosylated prohormone in pulse-chase experiments. The peptides produced from non-glycosylated prohormone were shown to be correct cleavage products. Therefore it was concluded that, with the possible exception of peptides from the N-terminal region of the prohormone, the carbohydrate on POMC plays no role in directing cleavage or in protecting the prohormone from random proteolysis. Tunicamycin treatment retarded N-terminal acetylation of melanotrophin but had no apparent effect on acetylation of β-endorphin. The mouse pars intermedia synthesizes two forms of POMC which differ in their degree of glycosylation. Our results indicated that, during secretion, the melanotrophs make no distinction between peptides derived from the two prohormones. J. Endocr. (1985) 107, 365–374

Neurointermediate lobe transplanted under the kidney capsule modifies the activity of the neurointermediate lobe in situ, but does not respond to opiate treatment

1986 ◽  
Vol 64 (4) ◽  
pp. 430-437 ◽  
Author(s):  
Christina Gianoulakis ◽  
Alka Gupta
Keyword(s):  
Pituitary Gland ◽  
Direct Effect ◽  
Anterior Lobe ◽  
Pars Intermedia ◽  
Morphine Treatment ◽  
Kidney Capsule ◽  
Neurointermediate Lobe ◽  
Elevated Content ◽  
Naloxone Treatment

To investigate the possibility of a direct effect of morphine on the pars intermedia cells of the pituitary gland, rat neurointermediate lobes (NIL) were transplanted under the kidney capsule. At 2 and 8 days posttransplantation the NIL transplant had maintained its morphological integrity. However, at 15 days posttransplantation the morphological integrity of the NIL transplant had started to deteriorate. The NIL transplant contained, synthesized, and released β-endorphin-like peptides. It was noticed that there was very little β-endorphin in the radiolabelled biosynthesized products, suggesting that either the maturation processing of proopiomelanocortin was modified, or that β-endorphin was released immediately as soon as it was formed and did not accumulate in the tissue. In support of the latter possibility was the elevated content of β-endorphin-like immunoreactivity in the sera of rats with a NIL under the kidney capsule. Furthermore, the NIL transplant seemed to produce a substance or substances which could decrease the content, the biosynthesis and the release of β-endorphin-like peptides by the NIL in situ. Treatment with either morphine or naloxone for 5 days did not change the β-endorphin-like immunoreactivity content in the NIL transplanted under the kidney capsule. However, a distinct decrease in the β-endorphin-like immunoreactivity in the NIL in situ of animals with or without a NIL transplant was observed following the morphine treatment. Naloxone treatment induced a decrease in the β-endorphin-like immunoreactivity content in the hypothalamus, but had no effect on the β-endorphin-like immunoreactivity content in the anterior lobe and NIL of the pituitary gland in situ or in the NIL transplant.

scholarly journals Volume Changes During Active Shape Fluctuations in Cells

2015 ◽  
Vol 114 (20) ◽  
Author(s):  
Alessandro Taloni ◽  
Elena Kardash ◽  
Oguz Umut Salman ◽  
Lev Truskinovsky ◽  
Stefano Zapperi ◽  
...  
Keyword(s):  
Volume Changes ◽  
Active Shape ◽  
In Cells

AN UNEVEN DISTRIBUTION OF CHOLINE ACETYLTRANSFERASE ACTIVITY IN THE PITUITARY NEUROINTERMEDIATE LOBE OF THE RAT

1980 ◽  
Vol 85 (3) ◽  
pp. 497-501 ◽  
Author(s):  
MARIA G. P. GALLARDO ◽  
M. A. CANNATA ◽  
J. H. TRAMEZZANI
Keyword(s):  
Pituitary Gland ◽  
Choline Acetyltransferase ◽  
Cholinergic System ◽  
Male Rats ◽  
Uneven Distribution ◽  
Pars Intermedia ◽  
Junction Area ◽  
Acetyltransferase Activity ◽  
Neurointermediate Lobe ◽  
Choline Acetyltransferase Activity

The neurointermediate lobe of the pituitary gland of male rats was assayed for choline acetyltransferase (CAT) activity. Precise microsample punches were obtained from neurohypophysial tissue, pure pars intermedia tissue and from the junction area between them. The level of CAT activity (pmol/h per μg protein) in the neurohypophysis, pars intermedia and junction area were 0·390 ± 0·038 (s.e.m.), 0·228 ± 0·042 and 1·824 ± 0·268 respectively. These values show an uneven distribution of CAT in the neurointermediate lobe. The hypothesis of a cholinergic system located in the junction area has been advanced.

PROTEIN BIOSYNTHESIS IN VITRO BY THE PARS INTERMEDIA OF THE MOUSE PITUITARY GLAND

1977 ◽  
Vol 72 (2) ◽  
pp. 173-179
Author(s):  
H. ISHERWOOD ◽  
V. F. THORNTON
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Protein Biosynthesis ◽  
Pars Intermedia ◽  
Secretory Product ◽  
Posterior Pituitary ◽  
Short Term ◽  
Pituitary Glands ◽  
Mouse Pituitary

SUMMARY During short-term incubations of isolated posterior pituitary glands of the mouse, isotopically labelled amino acids were incorporated into protein by the cells of the pars intermedia. Using labelled leucine, 5–10% of incorporated label was found in a protein (P1), with a molecular weight of about 75000. Protein P1 could be isolated from both fresh and incubated tissue, and was a normal and indeed major, secretory product of the pars intermedia, constituting more than 50% of the protein present.

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