Effect of chronic administration of insulin on pituitary gland content of growth hormone in the normal rat

1970 ◽  
Vol 48 (2) ◽  
pp. 85-89 ◽  
Author(s):  
Robert L. Hazelwood ◽  
John G. Galaznik
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Young Adult ◽  
Pituitary Gland ◽  
Chronic Administration ◽  
Female Rats ◽  
Pituitary Glands ◽  
Hypophysectomized Rats ◽  
Normal Rat ◽  
Gland Content

Acetone-dried pituitary glands from young adult female rats (starting weight 165–168 g) previously injected (s.c.) with doses of insulin of 0.5 U to 1.0 U/kg body weight for 4 days, and then with 2.0 U/kg 6 days a week for an additional 34 days, were bioassayed in young hypophysectomized rats for growth hormone content. Insulin-injected rats gained significantly more weight than saline-injected controls. The tibia cartilage width of the insulin-injected donor rats was greater than that of control rats after 9, 17, 24, and 31 days of insulin; pituitary gland preparations from these insulin-injected rats increased tibia cartilage widths slightly but significantly over those of rats injected with control pituitary gland preparations.

Renaturalizing the sexually dimorphic profiles of circulating growth hormone in hypophysectomized rats

1991 ◽  
Vol 124 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Nisar A. Pampori ◽  
Arun K. Agrawal ◽  
Bernard H. Shapiro
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Body Weight Gain ◽  
The Body ◽  
Female Rats ◽  
Male Rats ◽  
Sexually Dimorphic ◽  
Plasma Growth Hormone ◽  
Indwelling Catheter ◽  
Hypophysectomized Rats

Abstract. Hypophysectomy resulted in a total elimination of measurable circulating growth hormone with an associated loss of body weight gain. The typical sexually dimorphic plasma growth hormone patterns: pulsatile profiles in male rats and tonic-like secretion in female rats, were lost. The male- and female-dependent profiles of plasma growth hormone, monitored from serial blood collections, were restored by administering the hormone through a single electrically controlled external pump attached to an indwelling catheter, and by implanting osmotic pumps intraperitoneally, respectively. Restoring the natural patterns of plasma growth hormone in animals devoid of pituitaries, re-initiated body growth. However, the body weight gains in both sexes of hypophysectomized rats were much greater when rat growth hormone was introduced to the animals in a masculine (pulsatile) pattern that appeared to be independent of pulse frequency, rather than in a continuous feminine profile. Subcutaneous injections, the most commonly reported method of administration, produced low-amplitude, long-lasting plasma peaks that were not as effective as pulse infusion in restoring growth. The procedure allows manipulation of the hormone profile (i.e. number of pulses/day, pulse amplitude, and through duration in the pulsatile pattern, and plasma concentration in the tonic pattern) in order to identify, and thus study the presumed salient components of the pattern regulating growth hormone responses.

Involvement of prolactin in the onset of puberty in female rats

1984 ◽  
Vol 101 (1) ◽  
pp. 63-68 ◽  
Author(s):  
M. D. Gonzalez ◽  
F. López ◽  
E. Aguilar
Keyword(s):  
Body Weight ◽  
Pituitary Gland ◽  
Chronic Treatment ◽  
Single Injection ◽  
Treated Group ◽  
The Body ◽  
Female Rats ◽  
Adrenal Weight ◽  
Vaginal Opening ◽  
Pituitary Glands

ABSTRACT Pimozide (1 mg/kg per day), bromocriptine (1 mg/kg per day) or domperidone (0·1 mg/kg per day) administered daily to rats from day 21 did not change the age at which vaginal opening occurred, nor did they affect the body weight at that age. Therefore the evolution of prolactin levels was different in these three groups. The pimozide-treated group showed high prolactin levels measured on day 23, at vaginal opening and at first oestrus. In the bromocriptine-treated group, levels were undetectable on the day of vaginal opening. Chronic treatment with domperidone failed to increase prolactin levels on day 23 and at vaginal opening. Nevertheless, large increases were observed after a single injection of domperidone at both 21 and 30 days of age. A significant increase in LH observed on day 23 in the pimozide-treated group was the only effect on gonadotrophin levels which was detected. Ovarian weights were unaffected by the treatments, whereas adrenal weight was increased in the bromocriptine-treated group and decreased in the pimozide- and domperidone-treated groups. Female rats grafted on day 21 with one additional pituitary gland from adult (90 days) or young (21 days) donors showed a similar advancement in the time of vaginal opening, although the animals bearing an adult pituitary gland showed higher prolactin levels than those observed in animals grafted with young pituitary glands. This study suggested that the onset of puberty is not closely linked with the evolution of prolactin levels and that the hormone itself is not indispensible for the process. J. Endocr. (1984) 101, 63–68

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.

Single and repeated testing of growth hormone secretory capacity in hypopituitarism using growth hormone releasing factor

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S118-S122 ◽  
Author(s):  
O. BUTENANDT ◽  
M. EMMLINGER ◽  
H. DOERR
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Pituitary Gland ◽  
Bolus Injection ◽  
Hormone Deficiency ◽  
Test Results ◽  
Repeated Testing ◽  
Plasma Growth Hormone ◽  
Once Daily ◽  
Secretory Capacity

Abstract 38 patients with proven growth hormone deficiency (GHD) and 19 children with familial short stature received an iv GRF-bolus injection of 1 ug/kg body weight. Whereas in all control children plasma growth hormone rose significantly (mean of maximal values 36 ng/ml), only 7 out of 38 patients with GHD reached peak values of 8 ng/ml or more. GRF-priming by 1 ug GRF/kg BW given once daily s.c. for 5 days in 19 patients improved the response of the pituitary gland in 11. Thus, following the first GRF test, only 21 % of patients demonstrated function of the pituitary gland whereas 45 % did so when all test results are combined. To evaluate the pituitary function in patients with GHD correctly, GRF tests following a GRF priming period seems to be necessary to reactivate atrophic somatotropic cells of the pituitary gland.

Dissimilar Anxiety-like Behavior in Prepubertal and Young Adult Female Rats on Acute Exposure to Aluminium

2021 ◽  
Vol 22 ◽  
Author(s):  
Trina Sengupta ◽  
Sutirtha Ghosh ◽  
Archana Gaur T. ◽  
Prasunpriya Nayak
Keyword(s):  
Body Weight ◽  
Young Adult ◽  
Adult Female ◽  
Developmental Stages ◽  
Elevated Plus Maze ◽  
Age Groups ◽  
Female Rats ◽  
Acute Exposure ◽  
Adult Rats ◽  
Plus Maze

Background: Puberty is a developmental transition in which an estrogenic surge occurs, mediating the release of xenoestrogens, like aluminium. Aluminium’s effect on anxiety in rodents at the different developmental stages is inconsistent. Aims: This study aimed at investigating the effect of the metalloestrogenic property of aluminium on anxiety-like behavioral changes in prepubertal and young adult female rats. Objective: Considering this aim, our objective was to evaluate the anxiety-like behavior by the elevated plus maze in prepubertal and young adult female rats with or without acute exposure to aluminium. Methods: To address this property of aluminium, 5mg/Kg body weight (Al-5) and 10 mg/Kg body weight (Al-10) of aluminium was administered intraperitoneally to female rats at two developmental stages, prepubertal (PP; n = 8 for each dose) and young adult (YA; n = 6 for each dose) for two weeks. Post-treatment, three days behavioral assessment of the rats was done employing elevated plus maze. Results: Reduced escape latency was seen in Al-5, Al-10 pre-pubertal rats, and Al-5 young-adult rats on day 3. A significant reduction in open arm time was seen in the Al-5 young-adult rats. Aluminium treatment in the pre-pubertal rats reduced their head dipping and grooming. Reduced sniffing, head dipping, and stretch-attended posture in the treated young-adult female rats showed that they had impaired risk-taking tendency. Conclusion: Differential effect on the anxiety-like behavior in the pre-pubertal and young-adult female rats might be due to the metalloestrogenic property of aluminium, acting differently on the two age groups.

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.

Stimulation of food intake and weight gain in mature female rats by bovine prolactin and bovine growth hormone

1993 ◽  
Vol 264 (6) ◽  
pp. E986-E992 ◽  
Author(s):  
J. C. Byatt ◽  
N. R. Staten ◽  
W. J. Salsgiver ◽  
J. G. Kostelc ◽  
R. J. Collier
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Body Weight Gain ◽  
Mature Female ◽  
Female Rats ◽  
Bovine Growth Hormone ◽  
Female Rat ◽  
Moisture Percentage

Recombinant bovine prolactin (rbPRL) or bovine growth hormone (rbGH) was administered to mature female rats (10/treatment group) by daily subcutaneous injection for 10 days. Doses ranged from 7 to 5,000 micrograms/day (0.03-24 mg/kg body wt). Both rbPRL and rbGH increased body weight gain and food intake, but these parameters were increased at lower doses of rbPRL (7-63 micrograms/day) than rbGH (> 190 micrograms/day). Weight gain and food intake were maximally stimulated by 190 micrograms/day rbPRL, whereas maximal increased weight gain was obtained with the highest dose of rbGH (5,000 micrograms/day). Total carcass protein was increased by both hormones; however, protein as a percentage of body weight was unchanged. Similarly, neither rbPRL nor rbGH changed the percentage of carcass moisture. Percentage of body fat was increased by rbPRL but was decreased by rbGH. Weight of the gastrointestinal tract and kidneys was increased by both hormones, but increases were in proportion to body weight gain. These data confirm that ungulate prolactin is a hyperphagic agent in the female rat. In addition, they suggest that, while prolactin stimulates growth in mature female rats, this growth is probably not via a somatogenic mechanism.

THE ROLE OF THE ADRENAL GLAND IN THE CONTROL OF AMINO ACID INCORPORATION INTO PROTEIN OF ISOLATED RAT LIVER MICROSOMES

1960 ◽  
Vol 21 (2) ◽  
pp. 177-189 ◽  
Author(s):  
A. KORNER
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Female Rats ◽  
Male Rats ◽  
Rat Liver Microsomes ◽  
Hypophysectomized Rats ◽  
Normal Rat ◽  
Secondary Result

SUMMARY 1. Microsomes, isolated from rat liver a day after adrenalectomy, incorporate more radioactive amino acid into their protein in vitro than microsomes from normal rat liver. This enhanced rate of incorporation progressively declines with time after adrenalectomy until it reaches a plateau level which is below the normal rate of incorporation. 2. Following adrenalectomy microsomes isolated from liver of male rats show a greater rise in incorporating ability than those from liver of female rats, and maintain it longer. 3. Most of the increased incorporation observed in the in vitro system soon after adrenalectomy of the rat, and most of the decreased incorporation observed in rats adrenalectomized for some time, results from alterations in the microsomes which change their ability to incorporate activated amino acids into proteins. 4. Treatment of rats with cortisol acetate results in an increase in the ability of liver microsomes to incorporate amino acid into protein. This heightened incorporating ability is probably a secondary result of the breakdown of extrahepatic tissue protein which is stimulated by cortisol. 5. Somewhat similar responses to acute adrenalectomy and to treatment with cortisol were found in hypophysectomized rats. 6. The protein anabolic response of adrenalectomized rats to treatment with insulin, and of adrenalectomized-hypophysectomized rats to treatment with insulin or growth hormone, is greater than that shown by rats which possess adrenal glands.

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