Acetylation of Melanocyte-Stimulating Hormone and β-Endorphin in the Pars intermedia of the Perinatal Pituitary Gland in the Mouse

1986 ◽  
Vol 43 (2) ◽  
pp. 166-174 ◽  
Author(s):  
Hans J. Leenders ◽  
Jan J.W. Janssens ◽  
Henry J.M. Theunissen ◽  
Bruce G. Jenks ◽  
Abraham P. van Overbeeke
Keyword(s):  
Pituitary Gland ◽  
Pars Intermedia ◽  
Melanocyte Stimulating Hormone ◽  
Stimulating Hormone

Ontogeny of pro-opiomelanocortin (POMC) gene expression and translated products adrenocorticotrophin (ACTH) and α-melanocyte stimulating hormone (α-MSH) in the ovine fetal pituitary gland

1998 ◽  
Vol 10 (3) ◽  
pp. 233 ◽  
Author(s):  
D. M. Hagan ◽  
A. N. Brooks
Keyword(s):  
Pituitary Gland ◽  
Mrna Expression ◽  
Pars Intermedia ◽  
Basal Region ◽  
Melanocyte Stimulating Hormone ◽  
Pituitary Development ◽  
Pomc Mrna ◽  
Ovine Fetal ◽  
Stimulating Hormone

This study sought to determine the ontogeny of pro-opiomelanocortin (POMC) mRNA by in situ hybridization, and the expression of α–melanocyte stimulating hormone (α-MSH) and adrenocorticotrophin (ACTH) by immunohistochemistry, in the ovine fetal pituitary gland. Detection of POMC mRNA, and of ACTH and α-MSH immunoreactivity was first noted at Day 40 of gestation in the pars intermedia (PI) and the pars distalis (PD). After Day 70, α-MSH immunoreactivity was confined to the PI whereas POMC mRNA and ACTH immunostaining remained in both the PI and the PD. Increases (P < 0.05) of POMC mRNA expression were observed in the PI between Days 50–70 and levels then remained constant to Day 141 (term, 145 days). In the basal region of the PD, POMC mRNA expression was high at Day 40, declined (P < 0.01) by Day 50 and then increased progressively to Day 141 of gestation. The proportion of ACTH-immunopositive cells in the PD also fell from 14% at Day 40 to 11.4% at Day 70 and then increased to 15.3% by Day 141. In contrast, neither the level of POMC mRNA expression nor the percentage of corticotrophs changed in the region of the PD immediately adjacent to the PI. These data provide evidence for differential processing of POMC in a tissue-specific manner during early fetal pituitary development.

THE EFFECT OF INGESTION OF HYPERTONIC SALINE ON THE MELANOCYTE-STIMULATING HORMONE CONTENT AND HISTOLOGY OF THE PARS INTERMEDIA OF THE RAT PITUITARY GLAND

1970 ◽  
Vol 46 (2) ◽  
pp. 201-NP ◽  
Author(s):  
A. HOWE ◽  
A. J. THODY
Keyword(s):  
Control Level ◽  
Pars Intermedia ◽  
Type I ◽  
Melanocyte Stimulating Hormone ◽  
Level Of Activity ◽  
Numerous Type ◽  
Rat Pituitary ◽  
Stimulating Hormone

SUMMARY The changes in the content of melanocyte-stimulating hormone (MSH) and histology of the neuro-intermediate (n.i.) lobe were followed in rats which drank 2% sodium chloride for periods from 1–15 days. The pars intermedia showed a biphasic response. During the initial phase of 1–4 days there was a rapid rise in the MSH content, by 153% in the first day, falling back to control level by 4 days. These fluctuations were paralleled by an increase in the normally small numbers of Type 2 cells and at the same time numerous Type I cells showed hypertrophy and degranulation. After 4 days on saline there was a second rise in the MSH content, which was still evident at 15 days; during this second period the number of Type 2 cells declined to normal levels. The degranulated Type 1 cells also disappeared, most of Type 1 being smaller in size and intensely PAS-positive. After the ingestion of saline it apparently takes several days before the pars intermedia adapts to a new level of activity. The likely significance of these changes and the possibility of a relationship between the pars intermedia and the neurohypophysis are discussed.

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