ACTION OF ENZYME DIGESTED PITUITARY GLANDS OF THE SKIPPER-FROG ON THE OVULATION OF THE SAME

1960 ◽  
Vol XXXIII (II) ◽  
pp. 255-260 ◽  
Author(s):  
L. S. Ramaswami ◽  
A. B. Lakshman
Keyword(s):  
Pituitary Gland ◽  
Constant Temperature ◽  
Constant Temperature Bath ◽  
Predominant Role ◽  
Lower Vertebrates ◽  
Pituitary Glands ◽  
Stimulating Factor

ABSTRACT By using enzymes, the gonadotrophic factors in the skipper-frog pituitary glands have been selectively inactivated or destroyed. By incubating a known number of pituitary gland homogenate with ptyalin in a constant temperature bath for 5–6 h the follicle-stimulating factor is inactivated; with trypsin or pepsin, the luteinizing factor is inactivated. Bioassay on gravid skipper-frogs indicate that the ptyalin digested homogenate brings about profuse spawning while the trypsin or pepsin digested homogenates do not. When a combination of ptyalin digested and trypsin digested homogenates is injected into fresh gravid skipper-frogs, poor spawning is brought about. These experiments show that the luteinizing factor alone brings about more profuse spawning than when it is combined with the follicle-stimulating factor. It is likely, therefore, that in the lower vertebrates the luteinizing factor of the pituitary gland plays a more predominant role. The exact proportions in which the different dosages for the control and test animals are administered are also tabulated.

METABOLIC STUDIES WITH 131I-LABELED THYROXINE. II.

1963 ◽  
Vol 44 (3) ◽  
pp. 475-480 ◽  
Author(s):  
R. Grinberg
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Optic Nerve ◽  
Pituitary Gland ◽  
Time Interval ◽  
Time Intervals ◽  
Pituitary Glands ◽  
The Central Nervous System ◽  
Tentative Explanation

ABSTRACT Radiologically thyroidectomized female Swiss mice were injected intraperitoneally with 131I-labeled thyroxine (T4*), and were studied at time intervals of 30 minutes and 4, 28, 48 and 72 hours after injection, 10 mice for each time interval. The organs of the central nervous system and the pituitary glands were chromatographed, and likewise serum from the same animal. The chromatographic studies revealed a compound with the same mobility as 131I-labeled triiodothyronine in the organs of the CNS and in the pituitary gland, but this compound was not present in the serum. In most of the chromatographic studies, the peaks for I, T4 and T3 coincided with those for the standards. In several instances, however, such an exact coincidence was lacking. A tentative explanation for the presence of T3* in the pituitary gland following the injection of T4* is a deiodinating system in the pituitary gland or else the capacity of the pituitary gland to concentrate T3* formed in other organs. The presence of T3* is apparently a characteristic of most of the CNS (brain, midbrain, medulla and spinal cord); but in the case of the optic nerve, the compound is not present under the conditions of this study.

THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
List Type ◽  
Distilled Water ◽  
Hormone Activity ◽  
Isoelectric Precipitation ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
Prolactin Content ◽  
The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

In-vivo and in-vitro secretion of prolactin by lactating rat adenohypophyses as a function of intracellular age

1984 ◽  
Vol 101 (1) ◽  
pp. 27-32 ◽  
Author(s):  
F. Mena ◽  
G. Martínez-Escalera ◽  
C. Clapp ◽  
C. E. Grosvenor
Keyword(s):  
Pituitary Gland ◽  
Incubation Period ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Pituitary Glands ◽  
H 26

ABSTRACT Adenohypophysial prolactin of lactating rats was pulse-labelled by [3H]leucine injected i.v. at the time of removal of the pups. The [3H]prolactin concentration in the pituitary gland, analysed by polyacrylamide-gel electrophoresis, progressively fell as the time from labelling to removal of the pituitary gland increased from 8 to 24 h, which suggests that there was a loss of hormone as it aged within the gland. Suckling effectively provoked the depletion–transformation of total and [3H]prolactin (extracted at pH 7·2) when applied after 8 h but not when applied after either 16 or 24 h after removing the pups. In rats whose pups were removed for 8 h, suckling also depleted–transformed [3H]prolactin labelled 4 h, but not that labelled 1 h before suckling. The pituitary glands of other lactating rats were labelled with [3H]leucine injected i.v. at various times before removing the glands and incubating them in medium 199. The secretion into the medium of [3H]prolactin labelled either 4, 8, 16 or 24 h beforehand was maximal during the first 30 min then declined from 30 to 240 min of incubation. However, secretion of prolactin labelled 1 h and 10 min beforehand reached a maximum after 0·5–1 h and 2 h of incubation respectively, then remained constant during the remainder of the 4-h incubation period. The total 4-h secretion of [3H]prolactin was greatest (65% of preincubation concentration) from those glands labelled 4 h before in contrast to those labelled 10 min (15%) or 1 (38%), 8 (34%), 16 (18%) or 24 h (26%) before incubation. Taken together, these data suggest that prolactin synthesized 4 h earlier is more likely to be released in response to physiological stimuli than is more recently formed prolactin or prolactin which has remained in the pituitary gland for 16 h or longer. J. Endocr. (1984) 101, 27–32

High-Precision Constant-Temperature Bath

1932 ◽  
Vol 4 (2) ◽  
pp. 218-219 ◽  
Author(s):  
Alfred L. Ferguson ◽  
Kenneth Van Lente ◽  
Richard Hitchens
Keyword(s):  
High Precision ◽  
Constant Temperature ◽  
Constant Temperature Bath

The corticotrophic cells of the canine pituitary gland in pituitary-dependent hyperadrenocorticism

1983 ◽  
Vol 96 (2) ◽  
pp. 303-309 ◽  
Author(s):  
A. M. McNicol ◽  
H. Thomson ◽  
C. J. R. Stewart
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Pituitary Gland ◽  
Cushing’S Disease ◽  
Cushing's Disease ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Single Entity ◽  
Pituitary Glands ◽  
Corticotrophic Cells

The distribution of specifically stained corticotrophic cells has been studied in the pituitary glands of 11 dogs with pituitary-dependent hyperadrenocorticism. The results suggest that the disease is not a single entity, and that some cases are caused by primary abnormality of the pituitary gland whereas others appear to be the result of dysfunction of the hypothalamus or central nervous system. The patterns correspond closely to those demonstrated in the human pituitary gland in Cushing's disease, and confirm that the canine disease is a useful model for the study of the pathogenesis of the variants of the condition.

Convenient, inexpensive constant-temperature bath

1934 ◽  
Vol 11 (11) ◽  
pp. 627
Author(s):  
Ralph E. Dunbar
Keyword(s):  
Constant Temperature ◽  
Constant Temperature Bath

Posttranscriptional regulation of rat growth hormone gene expression: increased message stability and nuclear polyadenylation accompany thyroid hormone depletion

1992 ◽  
Vol 12 (6) ◽  
pp. 2624-2632
Author(s):  
D Murphy ◽  
K Pardy ◽  
V Seah ◽  
D Carter
Keyword(s):  
Growth Hormone ◽  
Thyroid Hormone ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Posttranscriptional Regulation ◽  
Anterior Pituitary Gland ◽  
Growth Hormone Gene ◽  
Gh Gene ◽  
Rat Growth ◽  
Pituitary Glands

In thyroid hormone-depleted rats, the rate of transcription of the growth hormone (GH) gene in the anterior pituitary gland is lower than the rate in euthyroid controls, and there is a corresponding reduction in the abundance of the GH mRNA. Concomitantly, the poly(A) tail of the GH mRNA increases in length. Examination of nuclear RNA from anterior pituitary glands of control and thyroid hormone-depleted rats revealed no difference in the length of pre-mRNAs containing the first and last introns of the GH gene. However, mature nuclear GH RNA is differentially polyadenylated in euthyroid and hypothyroid animals. We suggest that the extent of polyadenylation of the GH transcript is regulated in the cell nucleus concomitant with or subsequent to the splicing of the pre-mRNA. Experiments with anterior pituitary gland explant cultures demonstrated that the GH mRNA from thyroid hormone-depleted rats is more stable than its euthyroid counterpart and that the poly(A) tail may contribute to the differential stability of free GH ribonucleoproteins.

Effects of long-term administration of high doses of medroxyprogesterone acetate on hormone receptors and target organs in the female rat

1984 ◽  
Vol 103 (3) ◽  
pp. 287-293 ◽  
Author(s):  
F. Di Carlo ◽  
S. Racca ◽  
G. Conti ◽  
E. Gallo ◽  
G. Muccioli ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Medroxyprogesterone Acetate ◽  
Prolactin Receptor ◽  
Female Rats ◽  
Serum Prolactin ◽  
Target Organs ◽  
Term Administration ◽  
Pituitary Glands ◽  
High Doses

ABSTRACT The changes in oestrogen, progesterone and prolactin receptor levels in target organs, and the macroscopic and microscopic modifications of uterus, ovary, adrenal and pituitary gland induced by long-term administration of high doses of medroxyprogesterone acetate (MPA) were investigated in female rats. Medroxyprogesterone acetate was injected i.m. for 30 days at daily doses of 7·5, 15 and 75 mg/kg. Oestrogen and/or progesterone-binding capacities were remarkably reduced at all doses of MPA used both in the uterus and pituitary gland. Furthermore, MPA caused a very evident reduction in the weight of pituitary glands, ovaries, adrenals and uterus. In all MPA-treated rats corpora lutea were absent from the ovaries, whereas the adrenals showed a significant reduction in the thickness of the cortex. In accordance with this, there was no evidence of ACTH-producing cells in the pituitary glands. Prolactin-producing cells were also absent, while GH-producing cells were present. Serum prolactin levels were significantly reduced at all doses of MPA used. A dramatic reduction of prolactin receptor concentrations was observed in the liver and the ovaries of MPA-treated rats. The results suggest that MPA acts as an antioestrogenic drug both by reducing the number of oestrogen receptors in target tissues and by changing the structure (and perhaps the function) of those organs (pituitary glands, ovaries and adrenals) which are, directly or indirectly, a source of oestrogens. The decreased synthesis of prolactin and the reduction of the number of prolactin receptors (which, on the contrary, are both increased by oestrogens) might be considered as additional antioestrogenic effects of MPA. J. Endocr. (1984) 103, 287–293

Effect of Starvation on Pituitary and Serum Follicle-Stimulating Hormone and Luteinizing Hormone Following Ovariectomy in the Rat

1972 ◽  
Vol 50 (8) ◽  
pp. 768-773 ◽  
Author(s):  
E. A. Ibrahim ◽  
B. E. Howland
Keyword(s):  
Luteinizing Hormone ◽  
Pituitary Gland ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Intact Female ◽  
Pituitary Glands ◽  
Ad Libitum ◽  
Stimulating Hormone

The concentration of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in serum and pituitary glands was studied in intact female rats and rats that were ovariectomized on day 0 of the experiment and then starved or fed for 2, 4, 7, or 9 days. Ovariectomy resulted in enhanced rates of synthesis and release of FSH and LH as indicated by the significant (P < 0.01) rises in the concentration of both hormones in the pituitary gland and serum.Starvation resulted in a decrease in body and pituitary weight. The concentration of FSH and LH in pituitary glands of starved rats was higher (P < 0.05) than that in fed rats on days 7 and 9. The concentration of FSH and LH in serum of starved rats was increased after ovariectomy but the levels on days 7 and 9 were lower than those of fed rats.These results suggest that the synthesis of FSH and LH was enhanced in both starved and fed rats following ovariectomy while the rate of release of both hormones was decreased at 7 and 9 days of starvation in comparison with rats fed ad libitum.

scholarly journals Humoral Factors Influencing Erythropoiesis in the Fish (Blue Gourami—Trichogaster trichopterus)

Blood ◽  
1969 ◽  
Vol 33 (4) ◽  
pp. 573-581 ◽  
Author(s):  
ESMAIL D. ZANJANI ◽  
MAN-LIM YU ◽  
ALFRED PERLMUTTER ◽  
ALBERT S. GORDON
Keyword(s):  
Body Weight ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Test Animal ◽  
Humoral Factors ◽  
Highly Active ◽  
Factors Influencing ◽  
Lower Vertebrates ◽  
Stimulating Factor

Abstract Evidence is presented for the existence of a circulating erythropoiesis stimulating factor in the bled fish (blue gourami). Erythropoiesis is inhibited by starvation and increased following a single bleeding in the gourami. Administration of serum from the bled gourami to the starved gourami evokes a highly significant increase in erythropoiesis. Serum from normal non-bled fish fails to produce this effect. Large doses of sheep plasma ESF and human urinary ESF (16 units/100 Gm. body weight) stimulate erythropoiesis in the starved gourami. Smaller amounts, highly active in the polycythemic mouse, are without effect in the gourami. No in vitro stimulatory effect on radioiron uptake by peripheral red blood cells of the gourami was exerted by anemic gourami serum or mammalian ESF. The starved gourami may find use as a test animal for erythropoietic factors from other lower vertebrates.

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