EFFECT OF ACTIVE IMMUNIZATION TO LUTEINIZING HORMONE RELEASING HORMONE ON SERUM AND PITUITARY GONADOTROPHINS, TESTES AND ACCESSORY SEX ORGANS IN THE MALE RAT

1974 ◽  
Vol 63 (2) ◽  
pp. 399-NP ◽  
Author(s):  
H. M. FRASER ◽  
A. GUNN ◽  
S. L. JEFFCOATE ◽  
DIANE T. HOLLAND
Keyword(s):  
Luteinizing Hormone ◽  
Active Immunization ◽  
Male Rats ◽  
Male Rat ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Accessory Sex Organs ◽  
Gonadotrophin Releasing Hormone ◽  
Low Levels ◽  
Lh Rh

SUMMARY Autoimmunity to luteinizing hormone releasing hormone (LH-RH) in adult male rats, induced by immunization with LH-RH conjugated to bovine serum albumin, resulted in atrophy of the testes and secondary sex organs and aspermatogenesis. Both immunoreactive luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in serum and the pituitary were reduced to low levels compared with those of control animals. It is suggested that antibodies to LH-RH can inhibit the action of endogenous hormone and that LH-RH is, in fact, the gonadotrophin-releasing hormone in the rat, required for the release of both LH and FSH.

RESPONSE OF THE PITUITARY-TESTICULAR AXIS TO LUTEINIZING HORMONE-RELEASING HORMONE IN THE IMMATURE MALE RAT

1977 ◽  
Vol 84 (2) ◽  
pp. 254-267 ◽  
Author(s):  
H. Edward Grotjan ◽  
Donald C. Johnson
Keyword(s):  
Luteinizing Hormone ◽  
Control Level ◽  
Serum Testosterone ◽  
Male Rats ◽  
Male Rat ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Immature Male ◽  
Serum Lh ◽  
Lh Rh

ABSTRACT Follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone and androstenedione were measured by radioimmunoassays in the sera of immature male rats treated with luteinizing hormone-releasing hormone (LH-RH). A single dose of 10, 20, 40 or 80 ng of LH-RH produced a prompt increase in serum LH: significant changes in FSH were found only with the two larger doses. Serum testosterone increased to peak levels in 20 to 40 min and returned to control level by 120 min. Changes in androstenedione were temporally similar but smaller in magnitude. Four doses of 20 or 40 ng LH-RH given at 20 min intervals did not increase serum LH or testosterone concentrations above those found with a single injection; FSH was slightly higher after the fourth dose. However, 40 ng LH-RH given every 20 min for 2 h produced a dramatic increase in serum LH and FSH: serum and testicular androgens were also much higher during the second hour. A 2 h stimulation with 80 ng LH-RH given ip at 30 min intervals did not alter the response to the same treatment given 24 h later; i. e., neither the pituitary nor the gonad was primed by previous exposure to increased levels of LH-RH or gonadotrophins. These results suggest that a single pulse of LH-RH produces a predictable response in the animal, but multiple episodic stimuli produce variable responses: testes, on the other hand, produce androgens as long as gonadotrophins are available.

GONADOTROPHIN RELEASE BY A HIGHLY ACTIVE ANALOGUE OF LUTEINIZING HORMONE RELEASING HORMONE IN RATS IMMUNIZED AGAINST LUTEINIZING HORMONE RELEASING HORMONE

1977 ◽  
Vol 74 (2) ◽  
pp. 291-296 ◽  
Author(s):  
H. M. FRASER ◽  
J. SANDOW
Keyword(s):  
Luteinizing Hormone ◽  
Male Rats ◽  
Tertiary Butyl ◽  
Progressive Decline ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Highly Active ◽  
Normal Rat ◽  
Lh Rh

Immunization against luteinizing hormone releasing hormone (LH-RH) in adult male rats produced a progressive decline in LH and FSH in the circulation to low or non-detectable levels. d-Serine-tertiary-butyl6,des-glycine-NH210 LH-RH ethylamide is an analogue of LH-RH having highly active LH-RH properties in the normal rat. Because it is also immunologically different from LH-RH it can stimulate gonadotrophin release from the anterior pituitary gland of rats immunized against LH-RH without interference from the antibody. The analogue stimulated LH and FSH release in rats 15 weeks after immunization against LH-RH when antibody titre was highest, and after long-term (35 weeks) immunization against LH-RH. d-Serine-tertiary-butyl6,des-glycine-NH210 LH-RH ethylamide and related analogues are therefore potentially useful for reversing the effects of immunization against LH-RH.

CHANGES IN THE OVARIES OF RATS AFTER IMMUNIZATION AGAINST LUTEINIZING HORMONE RELEASING HORMONE

1978 ◽  
Vol 77 (1) ◽  
pp. 85-93 ◽  
Author(s):  
H. M. FRASER ◽  
T. G. BAKER
Keyword(s):  
Luteinizing Hormone ◽  
Follicular Development ◽  
Reproductive Capacity ◽  
Male Rats ◽  
Follicular Growth ◽  
Vaginal Smears ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Antibody Titres ◽  
Lh Rh

Rats were immunized against luteinizing hormone releasing hormone (LH-RH) and ovulation and follicular development were studied 12, 24 and 48 weeks later. The abolition of regular cyclic patterns of vaginal smears and the absence of luteal tissue in all but one of 32 rats showed that the immunization was effective in blocking ovulation. Follicular growth varied between rats and appeared to be dependent on whether the inhibition of LH-RH had been sufficient to affect the secretion of basal levels of gonadotrophins. Low levels of gonadotrophins were associated with poor follicular development, uterine atrophy and leucocytic vaginal smears, whereas levels of gonadotrophins similar to those in the dioestrous controls led to adequate follicular growth in the absence of ovulation, the production of cystic follicles, uterine stimulation and persistent vaginal oestrus. A group of rats was ovariectomized 12 weeks after immunization against LH-RH; animals with low antibody titres and large follicles responded with increases in the levels of LH and FSH in the blood, whereas in those with high antibody titres and little follicular development the concentrations of gonadotrophins remained low. The reproductive capacity of rats immunized against LH-RH was tested by caging them with normal male rats from 3 weeks after immunization. Although mating occurred in three rats during the first month, no offspring were produced. No matings occurred in the remaining 41 weeks.

ACTIVE IMMUNIZATION OF EWES AGAINST LUTEINIZING HORMONE RELEASING HORMONE, AND ITS EFFECTS ON OVULATION AND GONADOTROPHIN, PROLACTIN AND OVARIAN STEROID SECRETION

1978 ◽  
Vol 78 (1) ◽  
pp. 39-47 ◽  
Author(s):  
I. J. CLARKE ◽  
H. M. FRASER ◽  
A. S. McNEILLY
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Levels ◽  
Follicle Stimulating Hormone ◽  
Active Immunization ◽  
Plasma Prolactin ◽  
Luteinizing Hormone Releasing Hormone ◽  
Steroid Secretion ◽  
Releasing Hormone ◽  
Highly Active ◽  
Lh Rh

Three Scottish Blackface ewes were immunized against luteinizing hormone releasing hormone (LH-RH) conjugated to bovine serum albumin (BSA) and three control ewes were immunized against BSA alone. When the antibody titre to LH-RH became raised the treated animals failed to show oestrus or ovulate; they had significantly lower levels of plasma luteinizing hormone (LH) and higher levels of prolactin than the controls, whereas the levels of follicle-stimulating hormone (FSH) were unaltered. The integrity of the hypothalamus-pituitary-gonadal system of these animals was then challenged by the injection of a highly active analogue of LH-RH and by ovariectomy. An i.v. injection of 5 μg d-serine-t-butyl6 des-glycine-NH210 LH-RH ethylamide raised plasma LH and FSH. Ovariectomy caused an eight- and ninefold rise in plasma levels of LH and FSH respectively in controls, but failed to increase plasma levels of LH and FSH in the LH-RH-immunized ewes. Plasma prolactin concentrations in the LH-RH-immunized ewes were significantly reduced by ovariectomy.

STEROID PRIMING OF THE LUTEINIZING HORMONE RESPONSE TO LUTEINIZING HORMONE RELEASING HORMONE

1978 ◽  
Vol 77 (3) ◽  
pp. 293-299 ◽  
Author(s):  
L. V. BECK ◽  
M. BAY ◽  
A. F. SMITH ◽  
D. KING ◽  
R. LONG
Keyword(s):  
Luteinizing Hormone ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Normal Male ◽  
Initial Exposure ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Pituitary Tissue ◽  
Lh Rh

Perifusion experiments were performed to study the stimulatory effects of luteinizing hormone releasing hormone (LH-RH) on the release of LH from anterior pituitary tissue. Exposure of pituitary tissue from normal male rats to LH-RH (5 ng/ml for 5 min) induced a small release of LH; in tissue from ovariectomized rats receiving no pretreatment, the release was more than three times greater and in tissue from gonadectomized male or female rats pretreated with oestradiol benzoate and progesterone, the release was six times greater than that observed in normal rats. Further exposure of pituitary tissue from gonadectomized steroid-pretreated male and female rats to LH-RH (5 ng/ml) induced an increase in the level of LH even greater than that seen after the initial exposure (priming action of LH-RH); in tissue from ovariectomized rats receiving no pretreatment, less LH was released than after the first exposure to LH-RH and in tissue from normal male rats the response was unchanged.

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