Unilateral cryptorchidism with compensatory hypertrophy of descended testicle in prepubertal boys.

5 prepubertal boys with unilateral cryptorchidism and compensatory hypertrophy of the descended testicle, 22 prepubertal boys with unilateral cryptorchidism and without CTH, and 14 prepubertal normal boys were submitted to LH-RH and to HCG tests in order to study the hormonal behaviour in CTH phenomenon before puberty. High but normal peaks of plasma LH and FSH were observed after LH-RH in CTH boys who showed a significant increase of testosterone after HCG stimulation. On the contrary the LH response to LH-RH and the testosterone response to HCG of the boys with unilateral cryptorchidism and without CTH were, as expected, significantly lower than in the control ones.     

Suprainguinal ectopic scrota of TS inbred rats

A new rat line (TS inbred rats) showing uni- or bilateral ectopic scrota in about 70% of the males was established. Ectopic scrota were elongated pouches of the thin muscle layer under the suprainguinal body skin, in which hypoplastic testes and epididymides were seen. Genetic analysis revealed that the ectopic scrotum was controlled by multiple genes. Groups of 5 normal, uni- and bilaterally affected rats were killed at 25 weeks of age. Histologically, ectopic testes of uni- and bilaterally affected rats showed arrest of spermatogenesis at the primary spermatocyte stage. Contralateral testes of unilaterally affected rats were normally descended and showed normal spermatogenesis. No abnormality was seen in the urinary system. Plasma concentrations of FSH were significantly elevated in bilaterally affected rats but plasma concentrations of testosterone and LH were unchanged in uni- and bilaterally affected rats. Pituitary contents of LH and FSH were significantly elevated in bilaterally affected rats. The endocrinological status of TS inbred rats was therefore similar to that of experimentally induced cryptorchid rats.     

Effects of season of birth on the prepubertal pattern of gonadotropin secretion and age at puberty in beef heifers

There is an early transient rise in gonadotropin secretion in spring-born prepubertal heifers and there is an indication that this pattern is different in autumn-born heifers. The effect of season of birth on age and weight at puberty is equivocal. This study was designed to compare the temporal patterns of LH and FSH secretion between spring- and autumn-born heifers and to determine the effects of season of birth on age and weight at puberty. Blood samples from 2 groups of heifer calves born in spring (last week of March, n = 5) or autumn (last week of October, n = 5) were collected every other week from birth to puberty and every 15 min for 10 h at 6, 12, 18, 24 and 32 wk of age. Timing of puberty was determined by measuring progesterone in plasma samples collected every 2 to 3 d starting at 42 wk of age. Age and weight at onset of puberty did not differ between the 2 groups of heifers (P > 0.05); however, the autumn-born heifers tended to mature in a wider range of ages and weights. Based on the 10-h sampling periods, mean serum concentrations of LH and LH pulse frequency and amplitude were higher in spring-born heifers at 18 wk of age than in autumn-born heifers (P < 0.05). In spring-born heifers, LH pulse frequency increased over time to 32 wk of age, and LH pulse amplitude was higher at 12 and 18 wk than at 32 wk of age (P < 0.05). Autumn-born heifers had higher LH pulse frequency at 6 wk and showed a decrease in mean concentrations of LH at 12 and 18 wk of age (P < 0.05). The FSH pulse frequency of spring-born heifers was higher at 12 wk of age than in autumn-born heifers (P < 0.05), FSH pulse amplitude in autumn-born heifers decreased from 6 to 32 wk of age. It was concluded that although the mean age and weight at puberty did not differ between spring- and autumn-born heifers, the range in age and weight at puberty was wider in the autumn-born heifers. The patterns of LH secretion differed between spring- and autumn-born prepubertal heifers, with spring-born calves exhibiting an early rise in LH secretion, while mean serum concentrations of LH decreased during this period in autumn-born heifers.     

Lack of adrenarche in two children with precocious puberty secondary to hypothalamic hamartoma

Adrenarche, which occurs earlier than gonadarche in normal children, is marked by increases in plasma dehydroepiandrosterone and its sulfate (DHAS). Adrenarche and gonadarche can be dissociated in various situations, e.g. central precocious puberty, indicating that they are controlled by independent mechanisms. This report concerns 2 children with central precocious puberty secondary to hypothalamic hamartoma. Their plasma basal DHAS values, compared to other cases with central precocious puberty not secondary to hamartoma, remained low for chronological age and bone age over a follow-up of 6.3 (case 1) and 9.2 9.2 years (case 2): in case 1 (boy), DHAS was 9 micrograms/dl at chronological age 7.7 and bone age 13 years; in case 2 (girl), DHAS was 11 micrograms/dl for chronological age 10.5 and bone age 13.5 years. GH secretion was normal. Basal plasma cortisol levels as the levels during hypoglycemia and after corticotropin stimulation were all normal. These data suggest that hypothalamic hamartoma may affect the central control of adrenarche. They may also contribute to the diagnosis of hypothalamic hamartoma.     

Early diagnosis and treatment of ectopic pregnancy

During the period from 1995 to 1999, 64 patients were treated for ectopic pregnancy. All patients admitted to the department passed the same procedure including (complete preoperative laboratory findings, Beta HCG, serum progesterone and transvaginal colour Doppler). In patients who had ultrasound finding typical for ectopic pregnancy in combination with positive Beta HCG, conservative treatment was primarily done. In the rest of the patients, Beta HCG was tested every second day and in combination with the clinical and vaginosonographical findings the patients underwent diagnostic or operative laparoscopy. Out of 64 patients 36 had visible ectopic pregnancy when admitted to the clinical department. Three patients had no visible ectopic pregnancy neither at the time of their admission to the department nor at the time of laparoscopy. One of them had cervical pregnancy and the other two had pregnancies in the uterine part of the tube. The patient with cervical pregnancy was treated with metrotrexat (MTX) 12 mg daily in 5 doses. One patient with cornual pregnancy was treated with high doses of oxytocin infusion in combination with MEB intravenously 3 x 1 amp. The other patient with cornual pregnancy underwent laparoscopy with cornual resection and salpingectomy. Four of other tubar pregnancies were treated with metrotrexat 12 mg/day for 5 days. Other ectopic pregnancies were treated as follows: 36 laparoscopic salpingectomies, 10 laparoscopic salpingotomies with ovum expression, 9 adnexectomies by laparotomy, and 2 laparoscopic adnexectomies.     

The relationship between secretory patterns of gonadotrophic hormones and the attainment of puberty in bull and heifer calves born early or late during the spring calving season

It was suggested that an early increase in gonadotrophin secretion in calves aged between 6 and 24 weeks might be critical for initiating developmental changes culminating in puberty. An early rise in luteinizing hormone (LH) release appears to be caused by an increase in LH pulse frequency in bull calves and by an increase in LH pulse amplitude in heifer calves. Previously we have found differences in the characteristics of the LH rise between prepubertal beef calves born in spring or fall; however, age at puberty was not affected by season of birth. Here we report the LH/FSH secretory patterns in prepubertal bull and heifer calves (Hereford x Charolais), born in March or April, respectively (i.e., early or late during the spring calving season; six animals of each sex born at each time). The bull calves of both groups reached puberty (defined as an attainment of scrotal circumference of >or=28 cm) at 43.2+/-1.3 weeks of age (P>0.05). Age at puberty for March- and April-born heifer calves (defined as the age at which serum progesterone concentrations first exceeded 0.4 ng/ml) averaged 56.0+/-1.4 weeks (P>0.05). Based on blood samples taken weekly from birth to 26 weeks of age, and then every other week until puberty, bull calves born in March exceeded April-born bull calves in mean serum LH concentrations at 6, 10 and 12 weeks of age (P<0.05). Mean FSH concentrations were greater (P<0.05) in March-born compared to April-born bull calves from 34 to 32 weeks before puberty. Mean serum LH (at 40, 42 and 56 weeks) and FSH concentrations (at 2, 10, 20, 22-26, 30 and 56 weeks of age) were greater (P<0.05) in heifer calves born in April than March. On the basis of frequent blood sampling (every 12 min for 10 h), heifer calves born in April exceeded March-born animals in mean LH and FSH concentrations, at 5 and 25 weeks, and LH pulse frequency, at 5, 10 and 25 weeks of age (P<0.05). None of the parameters of LH secretion (i.e., mean concentrations of LH, LH pulse frequency and amplitude based on frequent blood collection) differed between March- and April-born bull calves in this study (P>0.05). In summary, March-born bull calves had greater mean serum LH and FSH concentrations prior to 24 weeks of age than April-born calves. April-born heifer calves had greater mean serum concentrations of LH and FSH but this difference was not confined to the early postnatal period. Although there were significant differences in absolute amounts of LH secreted, there were no differences in the frequency of LH secretory pulses amongst March- and April-born bull calves and no differences in LH pulse amplitude in heifer calves born in March or April. As these particular parameters of LH secretion, as well as age at puberty, are not affected by the time or season of birth, they may be primary hormonal cues governing sexual development in bulls and heifers, respectively.     

Hormone response of dairy cows with ovarian cysts after treatment with HCG or GnRH

Twenty lactating Holstein and Guernsey cows, diagnosed by rectal palpation as having ovarian cysts, were randomly divided within breed into two groups to receive either a single intramuscular injection of 100 μg of synthetic gonadotropin releasing hormone (GnRH) or an intravenous injection of 10,000 IU of human chorionic gonadotropin (HCG). The objective was to compare hormonal and clinical changes in cows with ovarian cysts following treatment with GnRH and HCG. Eight of ten and nine of ten cows given either GnRH and HCG, respectively, responded to treatment and subsequent fertility was not different between the two groups. Pre-injection plasma levels of LH, progesterone, and estradiol were highly variable. Mean plasma levels of LH, progesterone and estradiol did not differ between groups either following treatment (days 1–17 post-treatment), at the subsequent estrus, or during days 1–13 following the subsequent estrus. Mean LH levels did not differ significantly on the days either post-treatment or post-estrus except that levels were higher (P < .01) at the subsequent estrus as compared to the other days. Mean progesterone levels increased after treatment with either GnRH or HCG and were higher on days 5, 9 and 13 post-estrus and post-treatment as compared to the subsequent estrus. Mean levels of estradiol were higher (P < .05) at the subsequent estrus than any other time post-treatment or post-estrus. No other days were significantly different. In conclusion, GnRH and HCG are effective treatments for ovarian cysts in cattle. Endocrine response on days following treatment are similar for both compounds.     

Treating heifers with GnRH from 4 to 8 weeks of age advanced growth and the age at puberty

In heifer calves, an early transient increase in circulating concentrations of LH is associated with early follicular development and is thought to regulate the timing of puberty. In an attempt to hasten the onset of sexual maturity, the early rise in LH concentration was advanced by injecting heifer calves with 120 ng/kg of GnRH (n=6) twice daily from 4 to 8 weeks of age; control calves received saline (n=6). Blood samples were collected every 15 min for 10h at 4, 8, 14, 20, 26, 32, 38, 44 and 50 weeks of age. Treatment with GnRH increased mean circulating concentrations of LH at 8 weeks of age (P<0.05), LH pulse frequency at 4 and 8 weeks of age (P<0.05), and reduced the mean age at puberty by 6 weeks (56.8+/-1.7 versus 62.8+/-2.4 weeks of age, for GnRH treated and control calves, respectively; P=0.04). Body weight gain was greater in GnRH-treated calves than control calves (P<0.05), and the rate of weight gain was shown to be a significant covariate within age at puberty. In conclusion, we suggest that the timing of the early rise in LH concentrations is a critical signal involved in the timing of puberty in heifers.     

Comparison of bioassay and radioimmunoassay data for study of changes in the pattern of LH secretion from birth to puberty in the heifer

To define gonadotrophin secretion rates in the prepubertal heifer, 12 Hereford x Friesian heifers were blood-sampled at 15-min intervals for periods of 24 h every 4 weeks from 3 weeks of age until puberty. Radioimmunoassay of plasma LH concentrations showed that, although LH episode frequency increased with age, overall mean LH concentrations and basal LH concentrations decreased between 3 and 15 weeks of age and then increased to 35 weeks of age. The validity of these trends in relation to biological activity of plasma LH was investigated using an in-vitro Leydig cell bioassay. Samples were selected from 24-h profile bleeds of 4 heifers at 3, 7, 11, 15, 19, 27 and 39 weeks of age. No significant differences were found in the patterns of change in overall mean LH concentrations, basal LH concentrations or LH episode amplitude when comparing the estimates obtained by radioimmunoassay with those by bioassay from birth over the prepubertal period. These results indicate that the changes with age observed by radioimmunoassay are representative of changes in biologically active hormone.     

Advancement of puberty in ewe lambs by active immunisation against inhibin early in life

Active immunisation of lambs early in life with inhibin can advance puberty and increase ovulation rate but these effects appear not to be mediated through changes in FSH concentrations. The aims of this study were to advance puberty in ewe lambs and determine if increased plasma concentrations of gonadotropins are responsible for the advancement of puberty. Ewe lambs were immunised at 3, 7 and 15 weeks of age against either a synthetic inhibin alpha subunit peptide 1–32 conjugated to human serum albumin (HSA), or an inhibin preparation purified from porcine follicular fluid (porcine monoclonal purified inhibin; pMPI), or HSA alone (control immunogen).Immunisation with inhibin alpha peptide 1–32 produced antibodies which bound iodinated native bovine inhibin and advanced puberty (time of first ovulation) and increased ovulation rate but did not significantly increase plasma FSH concentrations, although LH concentrations were lower (P < 0.01) on a number of occasions. In contrast, immunisation with pMPI significantly (P < 0.01) increased FSH and LH concentrations following the first booster immunisation, although FSH was only transiently elevated. Despite these increases in gonadotropins, no advancement of puberty was observed in PMPI immunised ewe lambs.This study confirms that active immunisation of ewe lambs early in life against inhibin advances puberty via a mechanism which does not significantly increase plasma gonadotrophin concentrations. Immunisation to advance puberty also results in persistent increases in ovulation rates in later breeding seasons.     

Gonadotrophin secretion in prepubertal bull calves born in spring and autumn

The reproductive development of bull calves born in spring and autumn was compared. Mean serum LH concentrations in calves born in spring increased from week 4 to week 18 after birth and decreased by week 24. In bull calves born in autumn, mean LH concentrations increased from week 4 to week 8 after birth and remained steady until week 44. LH pulse amplitude was lower in bull calves born in autumn than in calves born in spring until week 24 of age (P < 0.05). There was a negative correlation between LH pulse frequency at week 12 after birth and age at puberty in bull calves, irrespective of season of birth, and LH pulse frequency at week 18 also tended to correlate negatively with age at puberty. Mean serum FSH concentrations, age at puberty, bodyweight, scrotal circumference, testes, prostate and vesicular gland dimensions, and ultrasonographic grey scale (pixel units) were not significantly different between bull calves born in autumn and spring. However, age and body-weight at puberty were more variable for bull calves born in autumn (P < 0.05). In a second study, bull calves born in spring received either a melatonin or sham implant immediately after birth and at weeks 6 and 11 after birth. Implants were removed at week 20. Mean LH concentrations, LH pulse frequency and amplitude, mean FSH concentrations and age at puberty did not differ between the two groups. No significant differences between groups in the growth and pixel units of the reproductive tract were observed by ultrasonography. In conclusion, although there were differences in the pattern of LH secretion in the prepubertal period between bull calves born in autumn and spring, the postnatal changes in gonadotrophin secretion were not disrupted by melatonin treatment in bull calves born in spring. Reproductive tract development did not differ between calves born in spring and autumn but age at puberty was more variable in bull calves born in autumn. LH pulse frequency during the early prepubertal period may be a vital factor in determining the age of bull calves at puberty.     

Effect of melatonin on pulsatile release of luteinizing hormone in female lambs.

This study investigated the effect of melatonin treatment of ewe lambs on LH pulsatility in an attempt to examine the mechanism whereby melatonin advances the onset of puberty. Six ewe lambs were given intravaginal melatonin implants at 12.8 weeks of age. Another six lambs received empty implants. All lambs were serially blood sampled every 15 minutes for six hours on several occasions prior to the onset of puberty. One week after implantation LH pulse frequency and mean LH levels were higher in treated lambs than the control lambs (pulse frequency 0.13/h vs 0.03/h; mean LH levels 2.0 +/- 0.2 ng/ml vs 1.3 +/- 0.1 ng/ml; p less than 0.05). Melatonin treatment failed to alter pulse frequency after the initial increase. Puberty was advanced by 3 weeks in the treated group. In the second experiment six lambs received melatonin implants at 13 weeks of age and another six lambs served as control. In this experiment blood samples were taken intensively during the first few weeks after treatment. Results of this study show that mean plasma LH levels and LH pulse frequency were again higher during the first week after implantation. This transient increase in LH release may be part of the mechanism initiating the eventual advancement of puberty although the significance of this increase is questionable. In both experiments the LH response to estradiol injection was monitored at various times after treatment, but no effects of melatonin were found, although the magnitude of the response increased with age.     

Interrelationships of porcine X and Y chromosomes with pituitary gonadotropins and testicular size

Endocrine and testicular responses to unilateral castration on 1, 10, 56, or 112 days of age were characterized in 132 Chinese Meishan (MS) x White composite (WC) crossbred boars in which testicular size associates with a quantitative trait locus (QTL) on X chromosome. At 220 days of age, testicles of boars unilaterally castrated on Day 1 or 10 weighed more and had greater total daily sperm production (DSP) than one testicle of bilaterally intact boars (P < 0.05); compensation did not double these two responses. Boars with MS alleles at the X chromosome QTL had smaller testicles, darker colored parenchyma, and lower total DSP than boars with WC alleles (P < 0.05). The MS alleles engendered greater (P < 0.05) plasma FSH and LH during puberty than WC alleles. Plasma FSH increased (P < 0.05) within 48 h of unilateral castration on Days 1, 10, and 56. Subsequent increases occurred earlier during puberty (P < 0.05) after unilateral castration at younger ages than after unilateral castration at older ages. Pubertal increases in plasma FSH and LH were greater (P < 0.05) in boars with MS alleles than in those with WC alleles for the X chromosome QTL. Breed of Y chromosome had no effect on testicular traits, FSH, testosterone, or estrone. For LH, boars with an MS Y chromosome had greater (P < 0.01) plasma LH across all ages than boars with a WC Y chromosome. We conclude that a gene or groups of genes that reside on the porcine X chromosome regulate testicular development and pubertal gonadotropin concentrations.     

Blood concentrations of gonadotrophins, prolactin and gonadal steroids in males and in non-pregnant and pregnant female African elephants (Loxodonta africana)

No seasonal variation in any of the hormones measured was apparent in males or females. Testosterone levels in males increased around puberty (10-11 years) and remained significantly higher in adult than prepubertal males. This was not accompanied by any significant change in levels of LH, FSH or prolactin. In non-pregnant females there was no apparent difference in levels of LH, FSH or prolactin with age. There was a significant increase in progesterone around puberty (12 years) but there was considerable overlap in values between prepubertal and adult females. During pregnancy, progesterone levels were significantly higher than in non-pregnant females with maximum levels occurring at mid-pregnancy (9-12 months). However, there was considerable overlap in values between non-pregnancy and pregnancy. Concentrations of LH and FSH decreased significantly during mid-pregnancy while prolactin levels increased dramatically during pregnancy; after 7 months of gestation until term levels were always at least 8 ng/ml greater than in any non-pregnant female. It is suggested that this consistent increase in plasma/serum levels of prolactin can be used to diagnose pregnancy in the elephant.     

A study of seasonally delayed puberty in the male hare, Lepus Europaeus.

The brown hare, Lepus europaeus, has a mating season which extends from January to September. Adult males exhibit pronounced seasonal changes in the reproductive tract which are associated with changes in LH secretion. Maximum plasma levels of immunoreactive LH occur between March and June and minimal levels in the autumn non-mating period from September to December; this seasonal cycle in gonadotrophin output is reflected by the appropriate changes in the secretion of testosterone from the testes and in the activity of the accessory sex glands. Juvenile animals reach puberty only during the adult mating season, and the age of puberty thus varies with the date of birth. Males born before May reach puberty and become fertile at 3 months of age, while those born from May to July grow to a mature body size during the autumn non-mating season but puberty is delayed for several months. Since some animals experiencing delayed puberty were found to have elevated plasma levels of LH and testosterone, it is concluded that puberty is not completely suppresed by the environmental effects of the autumn, but that the developmental process is prolonged, resulting in the juveniles being synchronized with the adults in their reproductive activity.     

Plasma LH,FSH, testosterone,and age at puberty in ram lambs actively immunized against an inhibin alpha-subunit peptide

Active immunization against inhibin has been shown to advance puberty and increase ovulation rate in ewe lambs; but in ram lambs, effects on puberty and sperm production are equivocal. The objective of the present study was to determine whether active immunization against an inhibin alpha-subunit peptide advances the onset of puberty in ram lambs. St. Croix hair sheep ram lambs were assigned to inhibin-immunized (n = 7) and control (n = 8) treatment groups. Lambs in the inhibin-immunized group were immunized against a synthetic peptide-carrier protein conjugate, alpha-(1-25)-human alpha-globulin (halpha-G), and control lambs were immunized against halpha-G. Lambs were immunized at 3, 7, 13, 19, 25, 31, and 37 weeks of age. On the day of immunization a blood sample was collected and lambs were weighed. Another blood sample was collected 1 week following each immunization. At 20 weeks of age additional blood samples were collected at 20 min intervals for 8h. Beginning at 20 weeks of age and at weekly intervals thereafter, scrotal circumference (SC) was measured and semen was collected using electroejaculation. A subsequent ejaculate was collected 1 week following onset of puberty, which was defined as the week of age when an ejaculate first contained > or =50 x 10(6) sperm cells. In control lambs, plasma alpha-(1-25)-antibody (Ab) was nondetectable. In inhibin-immunized lambs, alpha-(1-25)-Ab titer increased from 7 to 25 weeks of age and then plateaued at a level that varied (P<0.001) among animals. Body weight and SC of control and inhibin-immunized lambs were similar at the onset of puberty. At pubertal onset inhibin-immunized lambs were older than control lambs (31.9+/-0.5 vs. 29.5+/-0.7 weeks of age, P<0.05). Plasma FSH concentrations were similar in control and inhibin-immunized lambs from 3 to 38 weeks of age. Plasma LH levels were lower (P<0.01) in inhibin-immunized than control lambs. During the 8-h blood sampling period at 20 weeks of age, LH and testosterone concentrations were lower (P<0.05) in inhibin-immunized than control ram lambs, and the LH pulse frequency was similar in the two groups of animals. The decreased LH secretion is consistent with the immunoneutralization of a putative inhibin alpha-subunit-related peptide that stimulates LH secretion in ram lambs. Present findings show that active immunization against an inhibin alpha-peptide delays rather than advances puberty in ram lambs.     

Secretory patterns of leptin and luteinizing hormone in food-restricted young female sheep

Leptin, the product of the ob gene, has been proposed as a metabolic signal that regulates the secretion of GnRH/LH. This may be critical during prepubertal development to synchronize information about energy stores and the secretion of GnRH/LH. This study aimed to assess the effect of food restriction on the episodic secretion of leptin and LH in young female sheep. Five 20-week-old prepubertal females were fed a low-level diet for 10 weeks to maintain the body weight. Control females of the same age received food ad libitum. Blood samples were collected at 10-min intervals for six hours at 20, 26, and 30 weeks of age, and plasma leptin, LH, insulin and cortisol concentrations were measured. In the control group, no changes were found in pulsatile LH secretion characteristics. Mean LH concentrations and LH amplitude were lower in the food-restricted group than in the control group at 26 and 30 weeks of age. In the control group, pulsatile leptin secretion did not change. When compared to control lambs of the same age, the food-restricted group showed lower mean plasma leptin concentrations, pulse amplitude and plasma insulin levels, after 6 weeks of restriction (week 26), although by week 30, plasma leptin concentrations and plasma insulin rose to those of the control group. Leptin pulse frequency did not change, nor did mean plasma levels of insulin in the control group at any age studied. Mean plasma concentration of cortisol did not change within or between groups. These data suggest that plasma leptin concentrations may not be associated with the onset of puberty under regular feeding and natural photoperiod in lambs. Prolonged food restriction, however, induces metabolic adaptations that allow an increase of leptin during the final period, probably related to the development of some degree of insulin resistance.     

Transitory increase in plasma FSH and LH levels induces early vaginal opening and corpus luteum formation in ovarian transplants of rats ovariectomized at 20 days of age

The effect of a transitory increase in plasma FSH and LH levels on puberty has been investigated. Hormonal changes were induced by bilateral ovariectomy (OVX) at 20 days of age followed by implantation of two ovaries (donor animals 20-day-old) beneath the kidney capsule 1, 2 or 3 days later. In an other group of animals the two interventions were made in reversed order. Rats in which OVX was made first showed early vaginal opening. If ovarian implantation preceded OVX, these two interventions did not affect the time of vaginal opening. More than 1/3 of the ovarian implanted animals exhibiting early opening of the vagina contained corpora lutea three days after vaginal opening. FSH and LH levels of OVX + ovary implanted rats were from the third day on following implantations markedly different from the OVX controls and were in the range of intact or sham-operated rats. The present findings indicate that a transitory increase in plasma gonadotropin levels around twenty days of age may lead to precocious puberty.     

Growth hormone-releasing factor (GRF) induced growth hormone advances puberty in female buffaloes

Exogenous bovine growth hormone-releasing factor (bGRF) at the dose rate of 10 microg/100 kg body weight was administered intravenously (i.v.) to six Murrah buffalo heifers as treatment group, while another six buffalo heifers served as control group which received the vehicle (0.9% NaCl solution) at an interval of 15 days for a period of 9 months to study the effect of bGRF on puberty onset associated with temporal hormonal changes in peri-pubertal buffalo heifers. Blood samples were collected at 3-day interval from all the animals during the experimental period and plasma harvested was assayed for growth hormonal (GH), luteinizing hormone (LH) and progesterone. The day that plasma progesterone was greater than 1.0 ng/ml for three consecutive sampling days was defined as the day of puberty. Exogenous bGRF administration increased (P = 0.02) plasma GH concentration in treatment group over control group during the treatment of bGRF as well as during the peri-pubertal period. Plasma progesterone concentrations increased transiently earlier (P = 0.05) by 58.5 days in bGRF-treated buffaloes than that in the control group. However, plasma LH concentrations were unaffected by the treatment of bGRF (P = 0.48). Both plasma GH and LH in the buffalo heifers increased (P < 0.01) over time preceding puberty and the higher hormonal concentrations were maintained during the onset of puberty, and thereafter, the concentrations of both the hormones declined (P < 0.05) after puberty. GH and LH were positively correlated both before puberty (r = +0.59 and +0.63; P < 0.05 for control and treatment group, respectively) and after puberty (r = +0.42 and +0.46; P < 0.05 for control and treatment group, respectively) indicating the interaction and/or close relationship of GH and LH in the mechanism of puberty in buffalo species.     

Models for Predicting the Adult Height and Age at First Menstruation of Girls with Idiopathic Central Precocious Puberty

Background

It is difficult to determine whether to treat a given girl who has idiopathic central precocious puberty (CPP) with gonadotropin-releasing hormone analog (GnRHa) in terms of adult height (AH). The objective was to provide an easy tool for predicting AH and age at first menstruation at initial evaluation to help guide the decision regarding whether to treat.

Methods

Data analysis using multiple linear regression models was performed in 134 girls with CPP. Among them 78 were given GnRHa because of low predicted AH (n=45), pubertal luteinising hormone (LH)/follicle-stimulating hormone peaks (FSH) ratio (n=50) and/or high plasma estradiol concentration (n=45). 56 girls were followed without treatment.

Results

In the whole population, the actual AH (162.1±5.61 cm) was similar to target height (161.7±4.91 cm) and to AH predicted by the Bayley and Pinneau method (161.9±7.98 cm). Separated models for treated and untreated girls provide very close estimations, leading to a unique formula for both groups. The AH (cm) could be calculated at the initial evaluation: 2.21 (height at initial evaluation, SD) + 2.32 (target height, SD) – 1.83 (LH/FSH peaks ratio) + 159.68. The actual AH was lower than the calculated AH by more than 1 SD (5.6 cm) in 11 girls (8.0%). The time between onset of puberty and first menstruation (in untreated girls) can be estimated with: 10.9 - 0.57 (LH/FSH peaks ratio). The formulae are available at http://www.kamick.org/lemaire/med/girls-cpp15.html.

Conclusions

We established formulae that can be used at an initial evaluation to predict the AH, and the time between onset of puberty and first menstruation after spontaneous puberty. The similarity of the formulae for both groups suggests that the treatment had no significant effect on the AH. However, the criteria used to select treatment suggest that it prevents the deterioration of AH in cases with rapidly evolving form of CPP.