Effects of LH-RH infusion, castration and cryptorchidism on gonadotrophin and testosterone secretion in developing rams
Bibliographic record
Abstract
The relationship between the pituitary gland and testis in rams was studied from birth to sexual maturity.The concentrations of LH, FSH and testosterone increased between 5 and 7 weeks of age; the rise was not correlated with any specific cytological change in the testis.An augmented pituitary response to LH-RH was demonstrated as levels of gonadotrophin increased.It is unclear whether this change in sensitivity plays a role in initiation of the pubertal process because Sertoli cell maturation, the earliest detectable change in the seminiferous epithelium, occurs between 17 and 21 weeks of age.Spermatocytes.were first seen in biopsies taken at 31-36 weeks and spermatogenesis was established fully by 45 weeks.This second phase of testicular development was characterized by increases in prolactin, testosterone and LH.Leydig cells previously difficult to identify became recognizable at the time of sexual maturation.In newborn rams, castration produced significant increases in LH and FSH levels within 2-3 weeks, but higher basal FSH levels (2-to 3-fold) were observed at 5 than at 3 weeks of age.Cryptorchidism did not elevate LH or FSH significantly during the first year of life.FSH rose after this period to levels 2-to 3-fold higher than in normal rams, while LH and testosterone values remained in the normal range in spite of diminished spermatogenic activity; spermatids were absent and testis size was approximately 60% of that recorded in a normal ram.These studies demonstrate a rise in gonadotrophin and testosterone secretion in rams during the first 5-7 weeks of life, followed by a quiescent period of 8-9 months before a secondary increase occurs coincident with the establishment of sexual maturity.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".