EFFECT OF NEMBUTAL AND NIALAMIDE ON THE PARS INTERMEDIA AND SKIN COLOUR CHANGES IN RANA CYANOPHLYCTIS SCHNEIDER

1971 ◽  
Vol 68 (2) ◽  
pp. 264-270 ◽  
Author(s):  
N. H. Gopal Dutt ◽  
M. R. Rajasekharasetty
Keyword(s):  
Skin Colour ◽  
Prolonged Treatment ◽  
Pars Intermedia ◽  
Histochemical Analysis ◽  
Pentobarbital Sodium ◽  
Low Concentration ◽  
Colour Changes ◽  
Melanophore Stimulating Hormone ◽  
Stimulating Hormone

ABSTRACT The administration of pentobarbital sodium (nembutal) at low concentration causes darkening of the skin. However, at higher dose or after prolonged treatment a moderate blanching of the skin is noticed. Nialamide also produces a moderate blanching effect. Both these drugs considerably increase the number of colloid vesicles in the pars intermedia of the frog, Rana cyanophlyctis. These drugs, however, do not reverse the darkening of the skin due to ACTH in hypophysectomized frogs. Histochemical analysis suggests that the colloid vesicles may represent stored melanophore-stimulating hormone.

SKIN-COLOUR CHANGES IN THE LIZARD, ANOLIS CAROLINENSIS, IN RESPONSE TO LOCALIZED ELECTRICAL STIMULATION AND LESIONS IN THE DIENCEPHALON

1981 ◽  
Vol 89 (2) ◽  
pp. 241-NP ◽  
Author(s):  
J. H. HEMER ◽  
M. A. SALAS ◽  
J. L. LAPOINTE
Keyword(s):  
Electrical Stimulation ◽  
Functional Relationship ◽  
Colour Change ◽  
Anolis Carolinensis ◽  
Skin Colour ◽  
Pars Intermedia ◽  
Dorsal Region ◽  
Ventral Region ◽  
Colour Changes ◽  
Skin Lightening

A study was made of changes in skin colour in the lizard, Anolis carolinensis, in response to deep electrical stimulation at 0·2 mm intervals throughout the periventricular region of the diencephalon and the anterior brain stem. Double-barrelled glass microelectrodes with tip diameters of 3 μm were used. A 20 μA pulse-train consisting of a 500 Hz signal lasting for 1 s yielded localized responses. Skin darkening occurred only in response to stimulation delivered in the anterior and dorsal region of the diencephalon and skin lightening only in response to stimulation in a small area in the posterior and ventral region of the hypothalamus. Electrical lesions in the latter region resulted in permanent skin darkening. Surgical interruption of the hypothalamo–hypophysial neurosecretory tract did not block skin-colour change in response to dark or light backgrounds. It was concluded that MSH release is under tonic inhibitory control by hypothalamic neurones in Anolis. Both inhibitory and stimulatory neurones can be localized stereotaxically in the diencephalon and neither type corresponds with the neurosecretory neurones of the hypothalamo–hypophysial tract. The functional relationship between the stimulatory neurones and the inhibitory neurones and pars intermedia remains unclear.

scholarly journals In situ hybridization analysis of anterior pituitary hormone gene expression during fetal mouse development.

1994 ◽  
Vol 42 (8) ◽  
pp. 1117-1125 ◽  
Author(s):  
M A Japón ◽  
M Rubinstein ◽  
M J Low
Keyword(s):  
Gene Expression ◽  
Anterior Pituitary ◽  
Beta Subunit ◽  
Pars Intermedia ◽  
Pituitary Hormone ◽  
Pars Distalis ◽  
Mouse Development ◽  
Glycoprotein Hormone ◽  
Anterior Pituitary Hormone ◽  
Stimulating Hormone

We used 35S-labeled oligonucleotides and cRNAs (riboprobes) to detect the temporal order and spatial pattern of anterior pituitary hormone gene expression in (B6CBF1 x B6CBF1)F2 fetal mice from embryonic Day 9.5 (E9.5) to postnatal Day 1 (P1). Pro-opiomelanocortin (POMC) mRNA was expressed in the basal diencephalon on Day E10.5, in the ventromedial zone of the pars distalis on Day E12.5, and in the pars intermedia on Day E14.5. The common alpha-glycoprotein subunit (alpha-GSU) mRNA first appeared in the anterior wall of Rathke's pouch on Day E11.5 and extended to the pars tuberalis and ventromedial zone of the pars distalis on Day E12.5. Thyroid-stimulating hormone-beta (TSH beta) subunit mRNA was expressed initially in both the pas tuberalis and ventromedial pars distalis on Day E14.5, with an identical spatial distribution to alpha-GSU at the time. In contrast, luteinizing hormone-beta (LH beta) subunit and follicle-stimulating hormone beta (FSH beta) subunit mRNAs were detected initially only in the ventromedial pars distalis on Days E16.5 and E17.5, respectively, in an identical distribution to each other. POMC-, alpha-GSU-, TSH beta, LH beta-, and FSH beta-positive cells within the pars distalis all increased in number and autoradiographic signal with differing degrees of spatial expansion posteriorly, laterally, and dorsally up to Day P1. POMC expression was typically the most intense and extended circumferentially to include the entire lateral and dorsal surfaces of the pars distalis. The expression of both growth hormone (GH) and prolactin (PRL) started coincidentally on Day E15.5. However PRL cells localized in the ventromedial area similarly to POMC and the glycoprotein hormone subunits, whereas GH cells were found initially in a more lateral and central distribution within the lobes of the pars distalis. Somatotrophs increased dramatically in number and autoradiographic signal, extending throughout the pars distalis except for the most peripheral layer of cells on Day E17.5. Mammotrophs also increased in number but less abundantly than somatotrophs, and PRL expression remained more confined to central-medial and ventrolateral areas of the pars distalis up to Day P1. These data demonstrate distinctive patterns of expression for each of the major anterior pituitary hormone genes during development of the mouse pituitary gland and suggest that different groups of committed cells are the immediate precursors to the terminally differentiated hormone-secreting cell types.

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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