TIME-RELATED SECRETION OF GONADOTROPHINS AFTER A SINGLE INJECTION OF STEROID-FREE BOVINE FOLLICULAR FLUID IN PREPUBERTAL AND ADULT FEMALE RATS

1981 ◽  
Vol 90 (1) ◽  
pp. 69-76 ◽  
Author(s):  
W. P. HERMANS ◽  
M. H. M. DEBETS ◽  
E. C. M. VAN LEEUWEN ◽  
F. H. DE JONG
Keyword(s):  
Adult Female ◽  
Follicular Fluid ◽  
Single Injection ◽  
Female Rats ◽  
Adult Rats ◽  
Total Period ◽  
Normal Number ◽  
Pituitary Secretion ◽  
Old Rats ◽  
Intact Rats

The time-related changes in gonadotrophin concentrations after a single injection of steroid-free bovine follicular fluid (bFF), which contains material with inhibin-like activity, were studied in 25-day-old and adult female rats which either were intact or had been ovariectomized 2 days before. In ovariectomized and intact rats administration of bFF caused a selective suppression of FSH after 4–8 h in 25-day-old rats and after 3–4 h in adult rats. No systematic changes in concentrations of LH after bFF injection were observed. Relative suppression of FSH levels in adult rats was more pronounced and of longer duration than in 25-day-old rats. Moreover, the total period of suppression lasted longer in ovariectomized than in intact rats (12 and 8 h for 25-day-old and 24 and 15 h for adult rats respectively). Hypersecretion of FSH was found in intact rats after the initial suppression; this phenomenon was more pronounced and of longer duration in adult than in 25-day-old rats. No clear change in the numbers of healthy growing follicles was observed after injection of bFF into intact rats. These results indicate that the pituitary secretion of FSH responds quickly and selectively after administration of bFF to intact and ovariectomized, 25-day-old and adult female rats. The hypersecretion of FSH in intact rats might compensate for the initial suppression of this gonadotrophin, and may thus ensure the maturation of a normal number of follicles.

EFFECTS OF SINGLE INJECTIONS OF BOVINE FOLLICULAR FLUID ON GONADOTROPHIN CONCENTRATIONS THROUGHOUT THE OESTROUS CYCLE OF THE RAT

1982 ◽  
Vol 92 (3) ◽  
pp. 425-432 ◽  
Author(s):  
W. P. HERMANS ◽  
M. H. M. DEBETS ◽  
E. C. M. VAN LEEUWEN ◽  
F. H. DE JONG
Keyword(s):  
Adult Female ◽  
Follicular Fluid ◽  
Single Injection ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Follicular Maturation ◽  
Selective Suppression ◽  
Plasma Injection ◽  
Bovine Plasma

A single injection of steroid-free bovine follicular fluid (bFF), which contains inhibin-like activity, was given to adult female rats at 09.00 h on dioestrus-2 (the day after metoestrus), dioestrus-3, pro-oestrus or oestrus. Peripheral concentrations of gonadotrophins were measured at 2-h intervals after injection. Compared with values in control animals treated with bovine plasma, injection of bFF did not influence concentrations of LH. In contrast, at all days studied injection of bFF resulted in suppressed concentrations of FSH, during a period which started between 4 and 10 h after injection and lasted 4–12 h, depending on the day of the cycle. With the exception of pro-oestrus, the period of suppression was followed by one in which fluctuating levels of FSH were found; in general, resulting levels were higher though not significantly increased. This latter effect was most pronounced on dioestrus-2 and dioestrus-3, when levels of FSH, which were already low in control animals, were first suppressed during the 6 h after injection of bFF. These data, in conjunction with results from an earlier study in rats at dioestrus-1, showed that administration of bFF induces a fast and selective suppression of FSH secretion on all days of the cycle. This period of suppression was followed by one with fluctuating levels of FSH which showed a tendency to be higher, indicating that disturbances in FSH secretion, such as are caused by bFF, can be compensated for quickly. In this way the process of follicular maturation might be protected.

THE HYPOTHALAMUS AND PROPYLTHIOURACIL-INDUCED GOITRE IN THE RAT

1963 ◽  
Vol 42 (2) ◽  
pp. 254-262 ◽  
Author(s):  
J. J. van der Werff ten Bosch ◽  
H. E. Swanson
Keyword(s):  
Steady State ◽  
Thyroid Hormone ◽  
Adult Female ◽  
Normal Diet ◽  
Anterior Hypothalamus ◽  
Female Rats ◽  
Intact Rats

ABSTRACT Adult female rats were given a normal diet, or a diet which contained 0.15% propylthiouracil. At the beginning of the experiment one half of the rats were left intact, whilst the others received an electrolytic basal midline lesion in the anterior hypothalamus. Of each of the four groups of rats, one half was killed after 14 days, the others after 28 days. It was found (both after 14 and after 28 days) that the presence of a lesion reduced the thyroid weight to approximately 75% of the value in intact rats on the same diet, which might be normal or contain propylthiouracil. Propylthiouracil caused thyroid enlargement (to 278% after 14 days and 352–360% after 28 days) in intact rats as compared with intact rats on a normal diet, and in lesioned rats as compared with lesioned rats on a normal diet. It is concluded that lesions cause a lowered steady state of the thyroid-pituitary feed-back system, but that this system responds normally to the alteration of the steady state caused by the propylthiouracil-induced block in thyroid hormone output.

BEFUNDE AM GENITALTRAKTUS DER RATTE NACH CORTICOTROPIN-INJECTION UND IHRE DEUTUNG UNTER BERÜCKSICHTIGUNG DES ZELLBILDES DER ADENOHYPOPHYSE

1959 ◽  
Vol XXXII (II) ◽  
pp. 167-176 ◽  
Author(s):  
Walter Schätzle
Keyword(s):  
Adult Female ◽  
Single Injection ◽  
Anterior Lobe ◽  
Vaginal Epithelium ◽  
Female Rats ◽  
Normal Adult ◽  
List Type

ABSTRACT In normal adult female rats a single injection of 5 IU corticotrophin was followed by a retention of glucoproteid material in the anterior lobe of the hypophysis and by impairment of the luteinization. In spayed adult female rats the same corticotrophin administration caused stratification and mucification of the vaginal epithelium.

METABOLISM OF 20β-HYDROXY-4-PREGNEN-3-ONE IN UTERINE TISSUE OF NON-PREGNANT RATS IN VITRO

1976 ◽  
Vol 83 (3) ◽  
pp. 604-620 ◽  
Author(s):  
B. P. Lisboa ◽  
M. Holtermann
Keyword(s):  
Biological Activity ◽  
Adult Female ◽  
Female Rats ◽  
Uterine Tissue ◽  
Rat Uterus ◽  
Adult Rats ◽  
Pregnant Rats ◽  
Progesterone Metabolites ◽  
Ovariectomized Adult Rats

ABSTRACT In vitro experiments carried out with uterus preparations of ovariectomized adult rats indicate the presence in this tissue of a 20β-hydroxysteroid-oxidoreductase which catalyzes the conversion of 20β-hydroxy-4-pregnen-3-one to progesterone. Since a hepatic 20β-hydroxysteroid-oxidoreductase is absent in adult female rats, the myometrial enzyme can be responsible for the biological activity of 20β-hydroxy-4-pregnen-3-one in these animals. Besides progesterone five metabolites were isolated and identified after incubation of [4-14C]20β-hydroxy-4-pregnen-3-one with uterine tissue: 20β-hydroxy-5α-pregnan-3-one, 20β-hydroxy-5β-pregnan-3-one, 5α-pregnane-3α,20β-diol, 4-pregnene-3α,20β-diol and 4-pregnene-3β,20β-diol. The conversion of 20β-hydroxy-4-pregnen-3-one to progesterone permits us to regard all five steroids isolated as progesterone metabolites in the rat uterus. 20β-hydroxy-5β-pregnan-3-one is the first C21-metabolite with a 5β(H)-configuration isolated in the rat uterus, which indicates the presence of 5β-reductase in this tissue.

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.

Regrowth of atrophied skeletal muscle in adult rats after ending immobilization

1978 ◽  
Vol 44 (2) ◽  
pp. 225-230 ◽  
Author(s):  
F. W. Booth
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Adult Female ◽  
Total Protein ◽  
Recovery Time ◽  
Time Course ◽  
Citrate Synthase ◽  
Female Rats ◽  
Adult Rats ◽  
Wet Weight

The recovery time course of muscle atrophied by immobilization was followed after removal of hindlimb casts from adult female rats. Increases of only 9% in body weight, 4% in gastrocnemius weight, and 10% in soleus weight occurred in controls during the 78-day duration of the experiment. There were no increases in the amounts of total protein or of citrate synthase activities in gastrocnemius or soleus during the first 3 days after removal of hindlimb casts; thereafter, there were increases in these paramters. Citrate synthase activities per mg of gastrocnemius protein were significantly higher at the 16th and 50th day of recovery. No significant differences for citrate synthase activity per mg of soleus occurred during recovery. Until the 50th day of recovery, no significant differences for total protein in soleus and for total protein and wet weight of gastrocnemius were observed between control and recovery values. However, the wet weight of the soleus returned rapidly during recovery and was not significantly different from control during recovery.

Attenuated responses of muscle protein synthesis to fasting and insulin in adult female rats

1992 ◽  
Vol 262 (1) ◽  
pp. E1-E5 ◽  
Author(s):  
A. G. Baillie ◽  
P. J. Garlick
Keyword(s):  
Protein Synthesis ◽  
Adult Female ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Fiber Type ◽  
Female Rats ◽  
Adult Rats ◽  
Fractional Rate ◽  
The Individual

One-year-old adult female rats were fasted for 12 or 36 h followed by a 30-min infusion of insulin. The responses of the fractional rate of protein synthesis (Ks) in the individual muscles (measured in vivo) to fasting were small and mostly nonsignificant. After 12 h of fasting, only the epitrochlearis muscle (ET) showed a significant decrease in Ks, and, even after 36 h of fasting, a significant decrease in Ks was seen in only ET, extensor digitorum longus, and tensor fasciae latae (TFL). After the 36-h fast, infusion of insulin restored the fed Ks in all muscles except TFL. The fiber-type composition of the individual muscles appeared to influence the muscles' responsiveness to the fasting, since the highly glycolytic TFL was the most sensitive (particularly after 36 h of fasting), whereas the highly oxidative adductor longus and soleus muscles were unaffected by either fasting or insulin. In a second experiment, refeeding of fasted adult rats also had little effect on Ks, consistent with the low sensitivity to fasting shown by the first experiment. The parallel results in the two experiments confirmed that the low responsiveness to fasting and insulin infusion in these adult rats was not a result of failure to absorb in “fed” animals or insufficient levels of insulin during insulin infusions. In contrast, a third experiment showed that muscle protein synthesis in the gastrocnemius muscle from young adult (5-mo-old) female rats was significantly reduced after only 12 h of fasting.

HORMONAL ACTION ON MONOAMINE OXIDASE ACTIVITY IN RATS

1967 ◽  
Vol 45 (3) ◽  
pp. 355-362 ◽  
Author(s):  
A. Ho-Van-Hap ◽  
L. M. Babineau ◽  
L. Berlinguet
Keyword(s):  
Monoamine Oxidase ◽  
Adult Female ◽  
Oxidase Activity ◽  
Female Rats ◽  
Monoamine Oxidase Activity ◽  
Adult Rats ◽  
Young Rats ◽  
Mao Activity ◽  
Hormonal Action

Male young and adult rats were injected with thyroxin, hydrocortisone and puromycin. Monoamine oxidase (MAO) activity was studied in liver, brain, kidney, and heart with L-tryptamine-2-14C as substrate. After thyroxin treatment, heart MAO increased in young animals but decreased in adult animals. Thyroxin decreased liver MAO in adult animals. Brain MAO remained constant in all experiments, whereas kidney MAO showed a slight decrease after thyroxin injection. In young rats, puromycin did not prevent the increase in heart MAO caused by thyroxin injection. Hydrocortisone did not enhance MAO activity in liver, brain and heart. Of all organs studied, only the heart showed a marked increase of MAO with age. In female rats, thyroxin has little effect on brain and liver MAO, whereas it increases MAO activity in the heart of young and adult animals by 67% and 32% respectively. Adult female rats have twice as much heart MAO as males.

EFFECTS OF NEONATAL EXPOSURE TO MONOSODIUM GLUTAMATE ON THE ELECTRICAL ACTIVITY OF NEURONES IN THE MEDIOBASAL HYPOTHALAMUS, AND ON THE PLASMA CONCENTRATIONS OF THYROID-STIMULATING HORMONE AND PROLACTIN, FOLLOWING STIMULATION OF THE ROSTRAL HYPOTHALAMUS IN ADULT FEMALE RATS

1981 ◽  
Vol 89 (3) ◽  
pp. 379-387 ◽  
Author(s):  
D. J. SAPHIER ◽  
R. G. DYER
Keyword(s):  
Adult Female ◽  
Median Eminence ◽  
Monosodium Glutamate ◽  
Plasma Concentrations ◽  
Female Rats ◽  
Mediobasal Hypothalamus ◽  
Adult Rats ◽  
Thyrotrophin Releasing Hormone ◽  
Rostral Hypothalamus ◽  
Stimulation Of

Action potentials were recorded from 174 neurones in the mediobasal hypothalamus of ovariectomized adult female rats exposed neonatally to monosodium glutamate (MSG) and from 145 neurones in control rats. All of the animals, which were anaesthetized with urethane, had been ovariectomized for at least 3 weeks and received two injections of oestradiol benzoate (20 μg/100 g body weight, i.m.) 72 h and immediately before the recording experiments. The response of each neurone to electrical stimulation of the median eminence and rostral hypothalamus (preoptic and anterior hypothalamic areas; PO/AH) was analysed. The most striking feature of the results obtained was the significant (P < 0·001) loss of inhibitory responses in those neurones remaining in the adult rats after neonatal treatment with MSG. The loss of inhibitory responses applied to both stimulation sites. In each rat the response of one neurone, which was antidromically identified as projecting to the median eminence, was recorded before and during stimulation of the PO/AH at 50 Hz for 30 s in every min for 15 min. Before and after this stimulation blood was collected from a jugular vein for estimation by radioimmunoassay of concentrations of prolactin and TSH. In the MSG-treated rats significantly (P < 0·05) fewer neurones were inhibited by the 50 Hz stimulation than in control rats. In control rats the plasma concentrations of prolactin nearly quadrupled as an immediate consequence of this treatment, whereas in MSG-treated rats plasma concentrations barely doubled. However, in the MSG-treated rats plasma concentrations of prolactin continued to rise after stimulation ceased, possibly as a consequence of enhanced secretion of thyrotrophin releasing hormone.

Pituitary receptors for LH-releasing hormone (LHRH) and responsiveness to LHRH in adult female rats after neonatal monosodium l-glutamate treatment

1985 ◽  
Vol 107 (1) ◽  
pp. 9-13 ◽  
Author(s):  
S. E. Inkster ◽  
R. N. Clayton ◽  
S. A. Whitehead
Keyword(s):  
Adult Female ◽  
Female Rats ◽  
Serum Prolactin ◽  
Female Rat ◽  
Releasing Hormone ◽  
Old Rats ◽  
Lh Releasing Hormone ◽  
Ovarian Cyclicity ◽  
Pituitary Receptors

ABSTRACT The effects of neonatal monosodium l-glutamate (MSG) treatment on pituitary responsiveness to LH-releasing hormone (LHRH) and on pituitary LHRH receptors have been investigated in the intact adult female rat. Three- to four-month-old rats treated with MSG (4 mg/g body wt) on days 2, 4, 6, 8 and 10 after birth had significantly reduced ovarian and pituitary weights, showed an absence or disruption of ovarian cyclicity after puberty, and had significantly higher concentrations of serum prolactin despite normal levels of LH. In-vitro pituitary LH responses to LHRH were in the normal range for one group of treated animals whilst in a second group the LH responses were markedly enhanced. In contrast, the total number of pituitary LHRH receptors were significantly reduced in all MSG-treated animals showing that the increased pituitary responsiveness of MSG-treated animals is not attributable to an increase in pituitary LHRH receptors. J. Endocr. (1985) 107, 9–13

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