Two Possible Mechanisms for Precocious Puberty Induced in Female Rats by Pituitary Grafts

Gonzalez, D; Fj, López; Je, Sánchez Criado; Aguilar, E.

doi:10.1159/000124458

Cited by 7 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results confirm our initial hypothesis [4,10] concerning the existence of two mechanisms in precocious puberty induced by pituitary grafts: a PRL-dependent one when 'adult' pituitaries were used, and another LH-dependent one when 'young' pituitaries were used. This mechanism would be similar to the well-known precocious puberty induced by injections of HCG and PHSG.…”

Section: Discussionsupporting

confidence: 87%

“…Previous results [4,10] suggested that the precocious pu berty induced by a 'young' graft was not mediated by an in crease in PRL secretion, since no increased PRL plasma levels were obtained and the effect of the pituitary graft was not blocked by bromocriptine.…”

Section: Discussionmentioning

confidence: 88%

“…This effect, which is associated with an increase in plasma PRL con centration, can be blocked by bromocriptine treatment. However, precocious puberty induced in both male and female rats by grafting a pituitary gland from a 'young donor' rat (21 days old) was neither associated with increased PRL levels nor blocked by bromocriptine treatment [4,10]. This disagreement suggests the existence of two mechanisms in precocious puberty induced by a pituitary gland graft: the first is associated with the release of PRL by the graft and the second is not directly related to PRL] 10],…”

mentioning

confidence: 99%

See 2 more Smart Citations

Luteinizing-Hormone-Mediated Precocious Puberty Induced in Female Rats by a Prepuberal Pituitary Graft

Pinilla

López²,

Gonzalez³

et al. 1989

Neuroendocrinology

Self Cite

View full text Add to dashboard Cite

The present study analyzes the mechanism of precocious puberty induced in female rats after a ‘young’ pituitary graft (obtained from 21-day-old animals). For this purpose, the following experiments have been performed: (1) female rats were grafted or sham-operated on day 21 with a littermate’s pituitary the follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol plasma levels as well as the ovarian, uterine and adrenal weights were determined at different times after the graft; (2) female rats grafted or sham-operated on day 21 were treated with 0.2 ml of LH antiserum (LHAS) or the same volume of a normal horse serum (NHS); (3) female rats were injected on day 1 of life with 0.1 mg of estradiol benzoate or olive oil. Groups of these animals were decapitated daily between days 6 and 21 in order to measure gonadotropins and prolactin (PRL) pituitary content. Since on day 21 estrogenized females showed decreased gonadotropin content and normal PRL content, females in experiment 4 were grafted on day 21 with pituitaries obtained from control or neonatally estrogenized female rats. The results obtained showed that FSH, LH and estradiol plasma levels as well as ovarian and uterine weights increased after pituitary grafts. LHAS blocked the precocious puberty induced by the pituitary graft, and pituitaries obtained from neonatally estrogenized female rats were unable to modify the occurrence of puberty when grafted. In conclusion, this work evidences that precocious puberty induced by ‘young’ pituitary grafts was mediated by the increase in LH secretion from the graft.

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 88%

mentioning

confidence: 99%

See 1 more Smart Citation

Luteinizing-Hormone-Mediated Precocious Puberty Induced in Female Rats by a Prepuberal Pituitary Graft

Pinilla

López²,

Gonzalez³

et al. 1989

Neuroendocrinology

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, the advancement induced by grafting a pituitary gland from a 'young' donor (21 days old) was not associated with increased prolactin concentrations and cannot be blocked by bromocriptine. These results suggested the existence of two possible mechanisms in precocious puberty induced by pituitary gland grafts: one being prolactin-dependent and the other not directly related to prolactin (Gonzalez et al, 1986).…”

Section: Introductionmentioning

confidence: 82%

“…Blood samples were obtained before daily injections of bromocriptine or vehicle at 10:00 h on Days 21, 25, 35 and at decapitation performed on the day of balano-preputial separation. Samples were obtained by jugular venepuncture after light ether anaesthesia as described previously (Gonzalez et al, 1986).…”

Section: Methodsmentioning

confidence: 99%

Mechanisms of precocious puberty induced in male rats by pituitary grafts

Aguilar¹,

Bellido²,

Sánchez-Criado³

et al. 1988

Reproduction

View full text Add to dashboard Cite

Male rats were grafted on Day 21 of age with 'young' (21 days old) or 'adult' (90 days old) pituitary glands and then treated daily with 4 mg bromocriptine/kg or vehicle. Plasma samples were obtained on Days 21, 25 and 35 and when balano-preputial separation occurred. Both types of grafts advanced the age at which balano-preputial separation occurred and increased prolactin concentrations. Bromocriptine treatment reduced the prolactin values in both grafted groups, but did not block the advancement of puberty in rats treated with 'young' pituitary grafts. These results suggest the existence of two possible mechanisms in precocious puberty induced by pituitary grafts: one is prolactin-dependent (when 'adult' pituitary glands were used) and the other not directly related to prolactin (when 'young' pituitary glands were used).

show abstract