HORMONAL REQUIREMENTS FOR THE MAINTENANCE OF OESTRADIOL-INDUCED INHIBITION OF UTERINE SENSITIVITY IN THE OVARIECTOMIZED RAT

1970 ◽  
Vol 46 (3) ◽  
pp. 341-346 ◽  
Author(s):  
K. P. MEYERS
Keyword(s):  
Subcutaneous Injection ◽  
Ovariectomized Rats ◽  
Ovariectomized Rat ◽  
Single Subcutaneous Injection ◽  
The Third ◽  
Oestradiol Treatment ◽  
Progesterone Treatment ◽  
Endometrial Scratching

SUMMARY Ovariectomized rats treated with 2·5 or 5·0 mg. progesterone daily received a single subcutaneous injection of 0·2 μg. oestradiol on the third day of the progesterone treatment. The deciduomal response to trauma by endometrial scratching was used to determine the degree of uterine sensitivity at various times after oestradiol. Uterine sensitivity was partially and then completely lost 36 and 48 hr. after oestradiol administration. The inhibition of uterine sensitivity persisted until 9 and 11 days after oestradiol when the animals received 2·5 and 5·0 mg. progesterone daily. Uterine sensitivity was completely inhibited on day 11 with doses of oestradiol from 0·2 to 0·05 μg. Withdrawal of progesterone treatment for 48 or 72 hr., but not for 24 hr., after oestradiol treatment restored uterine sensitivity. These results show that the oestradiol-induced inhibition of uterine sensitivity in the progestational endometrium is maintained by continuous progesterone treatment and that the duration of this effect is dependent on the dose of progesterone given.

EFFECT OF RELAXIN ON OESTROGEN-INDUCED UTERINE LUMINAL FLUID ACCUMULATION IN THE OVARIECTOMIZED RAT

1974 ◽  
Vol 61 (3) ◽  
pp. 347-353 ◽  
Author(s):  
T. G. KENNEDY
Keyword(s):  
Guinea Pig ◽  
Subcutaneous Injection ◽  
Single Injection ◽  
Daily Treatment ◽  
Ovariectomized Rats ◽  
Ovariectomized Rat ◽  
Fluid Loss ◽  
Fluid Accumulation ◽  
Single Subcutaneous Injection ◽  
Fluid Formation

SUMMARY Uterine luminal fluid accumulation (ULFA) was induced in ovariectomized rats by twice daily treatment for 3 days with 0·5 μg oestradiol-17β. At the end of this treatment, rats were given a single subcutaneous injection of 0·2 ml 0·9% saline containing 0, 0·1, 1, 10, or 100 guinea-pig units (GPU) of relaxin, and ULFA was determined 15–17 h thereafter. It was reduced in animals receiving ≥ 1 GPU relaxin. This reduction in ULFA commenced 12 h after treatment of rats with 10 GPU relaxin, and was completed by 24 h. Ligation of the cervical end of the uterus prevented the loss of fluid in response to a single injection of relaxin, indicating the cervix as the route of fluid loss. Uterine luminal fluid accumulation was reduced to a greater extent by treatment of rats with 1 mg progesterone than by 10 GPU relaxin. Given concomitantly with oestrogen, relaxin had no effect on ULFA in horns which were ligated at the cervical end, indicating that relaxin did not inhibit luminal fluid formation. It is concluded from these results that the effects of progesterone on ULFA are not mediated by relaxin. The results, however, do not allow rejection of the hypothesis that the effect of prolactin on ULFA is mediated by relaxin.

Effects of luteolysis during late pregnancy on pituitary responsiveness to gonadotrophin-releasing hormone in the rat

1991 ◽  
Vol 128 (3) ◽  
pp. 411-418
Author(s):  
T. R. Koiter ◽  
G. C. J. van der Schaaf-Verdonk ◽  
G. A. Schuiling
Keyword(s):  
Plasma Concentrations ◽  
Control Level ◽  
Late Pregnancy ◽  
Ovariectomized Rats ◽  
Normal Delivery ◽  
Releasing Hormone ◽  
Oestradiol Treatment ◽  
Progesterone Treatment ◽  
Gonadotrophin Releasing Hormone ◽  
Series Of Experiments

ABSTRACT We investigated whether the increase in the gonadotrophin response to gonadotrophin-releasing hormone (GnRH) during the last days of pregnancy and the occurrence of parturition on day 22 of pregnancy in rats are due to the increase in the plasma concentrations of oestradiol-17β after luteolysis, which occurs around day 20. In a first series of experiments we studied the effects of s.c. implantation of two capsules containing oestradiol on basal and GnRH-stimulated secretion of LH and FSH before and after luteolysis. Before luteolysis, ovariectomy increased basal LH and FSH; oestradiol treatment prevented this increase partly (FSH) or completely (LH). Ovariectomy also lowered the LH response to the infusion of GnRH (100 ng/h). Oestradiol treatment, on the other hand, increased the LH and FSH responses of both intact and ovariectomized rats above the level in intact non-treated control rats. After luteolysis, ovariectomy increased basal FSH only. Treatment with oestradiol did not prevent the increase in basal FSH and ovariectomy diminished the LH response to GnRH infusion. Oestradiol treatment maintained the LH response in ovariectomized rats at the control level and increased the FSH responses of both intact and ovariectomized rats to a higher level than in control rats. Furthermore, the LH and FSH responses of the oestradiol-treated groups of intact and ovariectomized rats were higher after luteolysis than before. In a second series of experiments two capsules containing progesterone were s.c. implanted before or after luteolysis. Progesterone treatment suppressed the plasma concentration of oestradiol and the gonadotrophin responses to infusion of GnRH on the expected day of parturition in both groups of rats. Parturition was delayed only in the rats in which progesterone treatment had started before luteolysis. It was concluded that throughout pregnancy ovarian factors suppress basal FSH and that the increase in responsiveness to GnRH after luteolysis is due partly to an increase in oestradiol production and partly to an ovarian factor which augments the action of oestradiol. Furthermore, normal delivery does not require high plasma concentrations of oestradiol during the last day of pregnancy. Journal of Endocrinology (1991) 128, 411–418

Superovulatory response to single subcutaneous injection of Folltropin in Holstein and Sahiwal cows

1992 ◽  
Vol 37 (1) ◽  
pp. 260 ◽  
Author(s):  
A.K. Misra ◽  
S.A. Chaubal ◽  
G. Krishna Kishore ◽  
S. Rajeshwaran ◽  
B.V. Joshi ◽  
...  
Keyword(s):  
Subcutaneous Injection ◽  
Single Subcutaneous Injection ◽  
Sahiwal Cows

OBSERVATIONS ON CADMIUM DAMAGE AND REPAIR IN RAT TESTES AND THE EFFECTS ON THE PITUITARY GONADOTROPHS

1962 ◽  
Vol 24 (4) ◽  
pp. 453-NP ◽  
Author(s):  
M. ALLANSON ◽  
R. DEANESLY
Keyword(s):  
Subcutaneous Injection ◽  
Cadmium Chloride ◽  
Cytological Study ◽  
Interstitial Cells ◽  
Germinal Epithelium ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Long Term Effects ◽  
Single Subcutaneous Injection

SUMMARY Cadmium chloride, in a single subcutaneous injection, can destroy spermatogenic and interstitial cells in the rat testis (Pařízek, 1957) and produce changes in the pituitary. The interstitial tissue is restored by ingrowths from the tunica and full androgen secretion returns before there is any regeneration of germinal epithelium. A cytological study has been made of the peripheral and central pituitary gonadotrophs; the latter revert almost to normal as the interstitial tissue regenerates, whereas the former retain characteristic castration features, unless there is also regeneration of the germinal epithelium. This seems to indicate that in the normal testis there is a hormone contribution from the seminiferous tubules as well as from the interstitial cells. The long-term effects of cadmium on the testis depend on the dose. Early stages of tubule restoration have been studied, but after administration of 0·9 mg., actual proliferation of the germinal epithelium was rarely found—only in four out of twenty rats, 113 or 142 days after injection.

scholarly journals Dissemination and immunogenicity of live TRIC agent in baboons after parenteral injection: II. Experiments with a ‘slow-killing’ strain

1969 ◽  
Vol 67 (3) ◽  
pp. 449-455 ◽  
Author(s):  
L. H. Collier ◽  
Anne E. Mogg(Née Smith)
Keyword(s):  
Lymph Nodes ◽  
Subcutaneous Injection ◽  
Technical Assistance ◽  
Regional Lymph Nodes ◽  
Virulent Mutant ◽  
Single Subcutaneous Injection ◽  
Single Intravenous Injection ◽  
Peripheral Lymph ◽  
Homologous Strain ◽  
The Difference

SUMMARYAfter a single subcutaneous injection into baboons the MRC-4 strain of trachoma/inclusion conjunctivitis (TRIC) agent underwent limited multiplication at the injection site, but was then eliminated rapidly from the skin and regional lymph nodes. Forty-eight hours after a single intravenous injection, but not thereafter, it appeared in the peripheral lymph nodes and spleen. The single parenteral injections failed to immunize baboons against conjunctival challenge with the homologous strain. These findings contrasted with those previously reported for the more virulent mutant, MRC-4 f, which multiplied readily in the skin, lymph nodes and spleen, persisted in these tissues up to 3 weeks after injection, and conferred good immunity to conjunctival challenge with MRC-4. The difference in behaviour of MRC-4 and MRC-4 f might be accounted for, at least in part, by the use of a smaller inoculum of live MRC-4; but similar findings in guinea-pigs, reported elsewhere, suggest that the differences observed are real. In conjunction with previous work, the present study suggests that the immunogenicity of TRIC agent is closely related to the mass of antigen that can be administered to or propagated within the recipient.We are grateful to Mr D. Venters for his able technical assistance.

SENSITIZATION BY INSULIN TO THE DEXTRAN "ANAPHYLACTOID" REACTION

1957 ◽  
Vol 35 (1) ◽  
pp. 251-256 ◽  
Author(s):  
V. W. Adamkiewicz ◽  
Y. Langlois
Keyword(s):  
Small Dose ◽  
Subcutaneous Injection ◽  
Anaphylactoid Reaction ◽  
Crystalline Insulin ◽  
Single Subcutaneous Injection ◽  
Small Doses

A single subcutaneous injection of crystalline insulin (20 units) sensitizes considerably the rats to the dextran "anaphylactoid" reaction. This is a type of acute serous inflammation. Insulin precipitates the reaction after a very small dose of dextran (0.05–0.01 ml., 6% solution) has been injected into a "shock organ". Without insulin, such small doses of dextran are quite ineffective. Insulin also precipitates the reaction when dextran (1.0 ml., 6% solution) is injected peripherally on the back. In this site and at this dose, it rarely produces the reaction in normal rats. The sensitization manifests itself despite a cortisone pretreatment.

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