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PubMed1992

Steady-state amounts of alpha- and luteinizing hormone (LH) beta-subunit messenger ribonucleic acids are uncoupled from pulsatility of LH secretion during sexual maturation of the heifer.

Our primary objective for this study was to determine whether steady-state amounts of alpha- and LH beta-subunit mRNAs in the anterior pituitary are altered during sexual maturation in the bovine female. A secondary objective was to determine whether 17 beta-estradiol (E2) alters amounts of LH subunit mRNAs before onset of puberty. Heifers (7 mo old) were assigned to one of three treatments: 1) ovariectomized (OVX, n = 16); 2) OVX and administered E2 (OVXE, n = 16); or 3) ovary-intact (INTACT, n = 20). Pituitaries were collected at an estimated 120 days before onset of puberty (prepuberty) or 25 days before onset of puberty (peripuberty). Six INTACT heifers were used to determine time of puberty during the experimental period, and their pituitaries were collected 40 h after administration of prostaglandin F2 alpha (postpubertal INTACT group). Relative amounts of mRNAs for LH subunits in each pituitary were determined by Northern analysis and scanning densitometry. Amounts of alpha- and LH beta-subunit mRNAs were lower in pituitaries of INTACT heifers and OVXE heifers, regardless of stage of sexual maturation, than in those of OVX heifers. Amounts of alpha-subunit mRNA were similar in OVXE and INTACT heifers regardless of stage of sexual maturation. Amounts of LH beta-subunit mRNA did not change during sexual maturation in heifers in the INTACT group. Concentrations of E2 were higher and LH beta-subunit mRNA were lower in heifers from the prepubertal OVXE group than in heifers in all other treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1999

Self-assessment of sexual maturation in adolescent females with anorexia nervosa.

PURPOSE: To evaluate the accuracy of self-assessment of pubertal maturation and to determine the desired stage of pubertal maturity in adolescent females with anorexia nervosa. METHODS: Standardized figure drawings depicting Tanner's sexual maturation stages were given to a consecutive sample of 40 adolescent females with anorexia nervosa who were instructed to assess current and desired pubertal development. Pubertal development was assessed independently by two investigators. The percent agreement between physician and subject ratings was determined. RESULTS: Percent agreement between physician and subject ratings was 30% for developmental stage for breasts and 50% for pubic hair. Subjects underestimated breast development 3.4 times as often as they overestimated it and overestimated pubic hair development 1.5 times as often as they underestimated it. Multivariate probit analysis showed that inaccuracy in breast self-assessment was inversely related to a desire for sexual maturity (p < 0.05). Ninety percent of subjects stated that their desired stage of breast development was equal to or more mature than their present stage. Eighty percent stated that their desired stage of pubic hair development was equal to or more mature than their present stage. CONCLUSIONS: Self-assessment of sexual maturity by adolescents with anorexia nervosa using standardized figure drawings depicting Tanner's stages is not accurate. Patients desiring a sexually immature body were most likely to be inaccurate in their self-assessment of their pubertal stage.

Adolescent↗
PubMedDate not supplied

Serum lipids and blood pressure in relation to age and sexual maturity.

This study was designed to examine serum lipid profile and blood pressure in relation to age and sexual maturity. Written informed consent to participate was obtained from 42% of the eligible population of two Devon communities. The blood pressure of 343 boys and 336 girls, aged 11-16 years, was recorded and sufficient blood for analysis was obtained from 320 boys and 301 girls. Of these, sexual maturity of 221 boys and 209 girls was visually assessed using the indices developed by Tanner. In girls there was a significant (p less than 0.05) correlation between age and serum triglyceride level (r = 0.16) and in boys both serum cholesterol and HDL-cholesterol were significantly (p less than 0.01) and negatively correlated with age (r = -0.25 and -0.18 respectively). Girls had significantly higher (p less than 0.05) levels of HDL-cholesterol than boys but neither sex demonstrated significant changes (p greater than 0.05) in serum lipids or lipoproteins with sexual maturity. No significant differences (p greater than 0.05) were detected between the mean diastolic blood pressures of boys and girls but older boys had significantly higher (p less than 0.05) systolic blood pressures than similarly aged girls. Age was positively and significantly correlated (p less than 0.01) with blood pressure in both boys (systolic, r = 0.49; diastolic, r = 0.30) and girls (systolic, r = 0.28; diastolic, r = 0.29). More mature children were demonstrated to have both higher systolic and diastolic blood pressures than less mature children (p less than 0.05) but when allowance was made for school year group through analysis of co-variance the relationship for diastolic blood pressure in boys no longer remained significant. Blood pressures observed in this study do not raise general cause for concern but the data indicate that unfavourable serum lipid and lipoprotein profiles are common.

Adolescent↗
PubMed2006

Dietary patterns are associated with sexual maturation in Korean children.

The purpose of this study was to investigate the association between dietary patterns and sexual maturation among Korean children. A cross-sectional study was conducted in 422 boys and 365 girls aged 9-12 years living in Seoul, Korea. Three-day food records were obtained, and pubertal stages were determined with a questionnaire using Tanner stages. Body fat was measured by bioelectrical impedance analysis, and bone mass content at the right calcaneus was measured by portable dual-emission X-ray absorptiometry. Exploratory factor analysis with a Varimax rotation was applied to identify dietary patterns using twenty-four food groups. Four distinct dietary patterns--"rice and Kimchi", "shellfish and processed meat", "pizza and drinks" and "milk and cereal"--were obtained. Twenty-six per cent (24 % stage 2, 2 % stage 3) of boys had genital development, and 79 % (63 % stage 2, 16 % stage 3) of girls showed breast development. In boys, genital development was weakly positively associated with "shellfish and processed meat" dietary factor scores (odds ratio 1.65, CI 0.95, 2.89, P for trend 0.07) after adjusting for confounders. In girls, breast development was significantly positively associated with the factor score of "shellfish and processed meat" (odds ratio 1.88, CI 1.08, 3.26, P for trend 0.05). These results suggest that dietary patterns were related to body composition and sexual maturation among the Korean children. Further investigations are needed to identify components of the foods consumed in high amounts in these patterns and how they are related to sexual maturation.

Anthropometry↗
PubMed1983

Effect of sexual maturation and exhaustive exercise on myocardial glycogen metabolism.

Prepubertal, pubertal, and postpubertal (28, 45, and 60 days old, respectively) rats of both sexes were run to exhaustion on a motor-driven treadmill to determine whether sexual maturation was involved in the glycogen sparing phenomenon previously reported in the myocardium of female rats receiving high doses of estrogen. Positive work was calculated and was not different in the male and female age-paired rats. Liver glycogen was significantly depleted by 92-98% in male and 96-97% in female exercising rats of all ages. The exercise bout resulted in significant depletion of glycogen in the red and white portions of the vastus lateralis muscle of male and female animals. At 45 and 60 days of age female animals had significantly more glycogen in the red muscle at exhaustion than age-paired males. Myocardial glycogen was significantly depleted by 32, 38, and 41% in prepubertal and pubertal males and prepubertal females, respectively. Pubertal females depleted myocardial glycogen by 19% (P less than 0.05). Postpubertal male animals exhibited a 46% depletion of myocardial glycogen (P less than 0.01), while myocardial glycogen in sexually mature females was not decreased at exhaustion. These data indicate that a myocardial glycogen sparing phenomenon exists in vivo in sexually mature female rats. These data further suggest that the glycogen sparing phenomenon develops in association with sexual maturation.

Animals↗
PubMed1995

Effect of age and carcase composition on the onset of sexual maturity in quail under normal feeding regimens.

1. The effect of age and carcase composition on the onset of sexual maturity was investigated in Japanese quail (Coturnix coturnix japonica) reared under a normal feeding regimen. 2. At 42 d of age, when the quail had started to lay and hen day production was about 60%, layers were heavier and contained more carcase fat than those that were not laying. 3. The liver and the ovary weight were greater following the onset of sexual maturity than 1 or 2 weeks before (35 and 28 d respectively). 4. Carcase fat as well as age are critical requirements for the onset of sexual maturity in quail.

Aging↗
PubMed1996

Sexual maturation in East German boys.

According to the internationally accepted classification, sexual maturation was investigated in 8685 healthy East German boys by means of the status quo method and the probit regression analysis. The 3rd, 50th and 97th centiles were calculated for the development of both the male external genitalia and pubic and axillary hairs. The findings are in line with those of recent studies from different European countries. Special attention was paid to the stages at the beginning and at the end of sexual maturation, e.g. B 2, B 5; AH2, AH3; PH 2, PH5/6, etc.

Adolescent↗
PubMed1988

Identification and characterization of an abundant ovarian interstitial gland protein associated with sexual maturity in rabbits.

An abundant ovarian protein with a relative mol wt (Mr) of 37K and an apparent pI of 8, associated with the onset of sexual maturity in the rabbit, has been identified. Ovaries from sexually mature (greater than 6 months old) rabbits contain large quantities of this 37K protein, while none can be detected in ovaries of immature (1 and 2 months) animals. Analysis of polyacrylamide gel electrophoresis (PAGE) gels of mature ovarian homogenates demonstrates that this protein is more abundant than actin in these preparations. It appears to be tissue specific, since it was not detected in 16 other rabbit tissues tested. Autoradiographic analysis of proteins labeled with 35S in ovarian organ culture demonstrates that a protein of identical Mr and charge to the 37K protein is synthesized in this tissue. Polyclonal sheep antiserum has been produced to the two-dimensional PAGE-purified protein. Immunoblotting of two-dimensional PAGE gels shows specific recognition of this protein and two slightly more acidic proteins of the same Mr by this antiserum. These three protein species also stain identical colors with a silver-based color stain, further suggesting that these are charge variants of the same protein. This protein is not present in corpora lutea isolated form sexually mature ovaries and is present in interstitial cell-enriched ovaries of rabbits which have been actively immunized with zona pellucida proteins. Immunocytochemical localization studies further demonstrate that this protein is localized in the interstitial gland cells. These findings suggest that this 37K protein is not associated with either follicular or luteal cells, but, rather, is linked with the 20 alpha-hydroxyprogesterone-secreting interstitial gland cell population.

Animals↗
PubMed2006

Testosterone levels and sexual maturation predict substance use disorders in adolescent boys: a prospective study.

BACKGROUND: This investigation determined whether testosterone level and sexual maturation in boys biased development of socially nonnormative behavior culminating in a substance use disorder (SUD). METHODS: The subjects were 179 boys recruited in late childhood through a high-risk paradigm. Path analysis was used to evaluate the influence of testosterone level and sexual maturation in early adolescence (age 12-14) on attitudes toward antisociality, affiliation with deviant peers, and social potency in middle adolescence (age 16), illicit drug use by late adolescence (age 19), and SUD in young adulthood (age 22). RESULTS: Testosterone level predicted social potency and approval of aggressive/antisocial behavior. Sexual maturation mediated the relation between testosterone level in early adolescence and later affiliation with deviant peers. Social potency, approval of aggressive/antisocial behavior, and deviant peer affiliations predicted illicit drug use by late adolescence that in turn predicted SUD in young adulthood. CONCLUSIONS: This study demonstrated that pubertal processes in early adolescence influence the risk for SUD via effects on psychosocial functioning.

Adolescent↗
PubMed1993

Divergent selection for body weight and yolk precursor in Coturnix coturnix japonica. 9. Evaluation of traits associated with onset of sexual maturity.

An experiment was conducted to compare traits associated with onset of sexual maturity in Japanese quail lines. Lines divergently selected for high and low 4-wk BW (HW and LW), and high and low total plasma phosphorus at beginning of lay (HP and LP) were compared with a randombred line (RBC1) that served as the base population for HW, LW, HP, and LP. The HW sublines (HW-HP and HW-LP) and LP subline (LP-HW) were also compared to their respective line of origin. Most of the differences observed for males selected for a single trait were found for weight-selected rather than for phosphorus-selected lines. The patterns of significance closely followed differences expected due to the extreme diversity in BW for the HW and LW when compared with RBC1. Females generally matured approximately 2 wk later than males for HW, HP, and LP. Line LW females matured approximately 4 wk later than LW males. Differences were observed for variables associated with onset of sexual maturity for HW, LW, and HP when compared with RBC1. Observed changes in carcass variables for sublines were generally associated with reductions in BW for HW-HP, and HW-LP versus HW and for increases in BW for LP-HW versus LP. The differences were likely due to the fact that two-trait selection (BW for males and total plasma phosphorus in females) has allowed weights to diverge when compared with lines selected for single traits.

Age Factors↗
PubMed2006

Effects of atrazine on sexual maturation in female Japanese quail induced by photostimulation or exogenous gonadotropin.

The herbicide atrazine has gained recent attention for its reported effects on reproduction in amphibians. The present study examined the putative effects of atrazine during sexual maturation in the photostimulated female Japanese quail. Furthermore, the effects of atrazine on birds administered exogenous gonadotropin (pregnant mare serum gonadotropin [PMSG]) were investigated. Atrazine was administered up to 1,000 ppm in the diet to female quail undergoing photoperiodically induced sexual maturation. At high dietary concentrations, atrazine exhibits signs of overt toxicity with reductions in growth, feed intake, and liver weights, but these effects were dependent on the timing of treatment administration. Atrazine did not influence the weights of reproductive tissues (ovary and oviduct) or circulating concentrations of luteinizing hormone (LH). However, high concentrations of atrazine depressed circulating concentrations of estradiol. Treatment with atrazine for four weeks during sexual maturation inhibited growth but did not affect any other parameter assessed (feed intake, liver, ovary, or oviduct weights or the circulating concentrations of LH and estradiol). In birds receiving daily injections of PMSG, atrazine reduced growth, feed intake, and liver weights. However, PMSG-induced gonadal and oviduct growth was not affected by atrazine. The present results suggest that dietary atrazine exhibits limited reproductive toxicity in female quail during sexual maturation and only at concentrations above ecological relevance.

Animals↗
PubMed1994

The interrelation between photoperiod, growth hormone, and sexual maturation of adult Atlantic salmon (Salmo salar).

The plasma profiles of growth hormone (GH) in adult male and female Atlantic salmon were determined in relation to manipulation of the photoperiod and to the development and timing of sexual maturation. Fish were exposed to natural light (NL) or NL + 24L:0D additional light over the netpens from January (ALJ) or March (ALM) to July. Thereafter, these groups were brought indoors, subdivided, and subjected to simulated natural photoperiod (SNP), continuous light (24L), or short day (8L). Assay of salmon GH by RIA in monthly plasma samples revealed that GH levels were generally < 1 ng ml-1 during January to June and were only slightly affected by additional light in January or March. ALJ-24L treatment, and to a lesser extent, ALM-24L treatment, was effective in preventing sexual maturation, and GH levels of immature fish continued to be < or = 1.5 ng ml-1. On the other hand, in sexually maturing fish, GH levels increased to 2-5 ng ml-1 months prior to ovulation. Short-day photoperiod (8L) from July advanced ovulation and spermiation, whereas continuous light from July delayed these processes. The timing of the increase of GH levels was shifted in a parallel manner, indicating a functional relationship between plasma GH levels and the process of sexual maturation.

Animals↗
PubMed1988

[Role of brain serotonin in the regulation of sexual maturation in male rats].

The effect of decrease of the brain serotonin level in different periods of prepubertal development on sexual maturation of male rats, was studied. Injections of p-CPA on the 30th and 34th days of life activated the endocrine function of testis in 60-day old animals. Injections of p-CPA later in life, on the 40th and 44th days, delayed sexual maturation as revealed by a decrease of spermatogenesis and endocrine function of testis. The data obtained suggest that serotonin has a dual role in regulation of the rate of sexual maturation in different periods of prepubertal age.

Animals↗
PubMed2004

Growth and sexual maturation during long-term treatment with risperidone.

OBJECTIVE: This study assessed the impact of risperidone on growth and sexual maturation. METHOD: The pooled database of five studies included 700 children ages 5-15 years with disruptive behavior disorders. All evaluable patients had received risperidone for 11 or 12 months. Those evaluable for growth also had baseline and 11- or 12-month height measurements (N=350); girls >/=9 years and boys >/=10 years who were evaluable for sexual maturation also had baseline and 11- or 12-month Tanner staging (N=222). RESULTS: Risperidone-treated children had a mean increase in height 1.2 cm greater than the reference population, and they experienced no delay in progression through Tanner staging. Transient increases in prolactin did not correlate with growth or sexual maturation. CONCLUSIONS: In this retrospective analysis, there was no evidence of statistically or clinically significant growth failure or delay in pubertal onset or progression in children treated for up to 1 year with risperidone.

Adolescent↗
PubMed1997

Cone photoreceptor topography in the retina of sexually mature Pacific salmonid fishes.

We examined the retinal cone topography in sexually mature individuals from four species of Pacific salmonid fishes by using semithin plastic sections. We identified variations in cone density and cone arrangements and noted the presence of putative ultraviolet (UV) cones. Putative UV cones were found over an area extending dorsotemporally from the center of the retina. Because most of the putative UV cones are believed to disappear in early ontogeny, their presence over a large proportion (15-20%) of the surface area of the adult retina suggests that they may be reincorporated prior to or at sexual maturity, at least in rainbow trout. Cone density varied across the retina, with highest values at the peripheral margin. Relatively high densities were observed ventrotemporally (in all specimens) and, to a lesser extent, dorsonasally (7 of 11 specimens). The higher cone density in the ventrotemporal retina may represent a retinal specialization in the part of the visual field located above and in front of the animal. Lowest cone densities were found dorsocentrally and coincided approximately with the distribution of putative UV cones, raising the possibility that these cones may not be used in visual tasks requiring the higher visual acuity normally associated with higher cone densities. We also report a novel cone arrangement that consists of rows of double cones inserted between rows composed of single-double cone pairs alternating in position.

Animals↗
PubMed2003

Physical growth and sexual maturation of boys in Chapaevsk, Russia.

We characterized physical growth and sexual maturation in 2,579 boys, ages 10 through 16.99 years, residing in Chapaevsk, Russia in order to establish region-specific reference data. Age-specific norms were established for height, weight, and BMI, and compared to US reference data by z-score analysis, while mean heights and weights by age were compared to published national Russian data. Compared to US boys, height was slightly lower (overall z-score -0.18) at all ages except the oldest (16-16.99 yr), while weight and BMI were moderately lower (overall z-score -0.52 and -0.61, respectively). Chapaevsk boys were significantly taller (1.15 cm) and thinner (-1.28 kg) than the broader Russian sample. The median ages of stage 2 genitalia and pubic hair development were 11.9 and 12.7 years, respectively. In conclusion, Chapaevsk boys are thinner than both US and Russian boys, and have a later onset of puberty and attainment of sexual maturity than boys from other countries.

Adolescent↗
PubMed2005

Obesity induced during sexual maturation is linked to LDL-triacylglycerols in Yucatan miniature swine.

The incidence of childhood obesity is rising dramatically throughout industrialised countries. To evaluate and study the impact of childhood obesity on lipoprotein metabolism, we developed a new animal model of premature obesity. Yucatan mini-pigs aged 4 months were studied over a 12-month period from childhood to adulthood. Animals were divided into two groups: the first group were overfed a Western misbalanced diet; the second group were normally fed a recommended human-type diet. Cholesterol and triacylglycerol concentrations in VLDL-, LDL- and HDL-lipoproteins were followed from baseline to adulthood by fast protein liquid chromatography. At 10 (the end of sexual maturation) and 16 months old (adulthood), liver, visceral and subcutaneous adipose tissues were sampled. Real-time RT-PCR was performed in order to compare apo AI, apo B, apo C-III, PPAR-alpha, insulin receptor and lipoprotein lipase gene expression between groups and ages. Differences between groups were observed only after sexual maturity. Adult overfed mini-pigs had a higher LDL-cholesterol:HDL-cholesterol ratio (P < 0.05; 0.55 (SE 0.06) for overfed v. 0.42 (SE 0.04) for normally fed pigs at the tenth month of the study). In both groups, VLDL-triacylglycerol decreased (P < 0.05). VLDL-triacylglycerol evolution in the overfed group was associated with an increase in LDL-triacylglycerol plasma concentrations (P < 0.05) after sexual maturation. LDL-triacylglycerol concentration in overfed mini-pigs went from an average of 0.28 mmol/l before sexual maturation to reach an average concentration of 0.56 mmol/l afterwards. This phenomenon has never been observed in similar studies when obesity is induced in adult mini-pigs and may represent a specific hallmark of an obesity induced during sexual maturity.

Animals↗
PubMed2000

Simultaneous determination of plasma ovarian and thyroid hormones during sexual maturation of the hen (Gallus domesticus).

The concentrations of ovarian steroids (estradiol--E2, progesterone--P4 and testosterone--T) and thyroid hormones (thyroxine--T4 and triiodothyronine--T3) were determined in blood plasma of the domestic hen during sexual maturation and the initial period of egg lay. Blood samples were collected from Hy-Line pullets at 3 day intervals from days 87 to 144 day of life, i.e. 42 days before and 14 days after the onset of egg lay (OEL). Ovarian and thyroid hormones were measured by RIA methods. During sexual maturation an increase in ovarian steroids in the blood plasma was observed. The maximum E2 and P4 levels were recorded on day 6 and day 3 prior to OEL, respectively. In the case of plasma T level, an increase from 42 to 18 days before OEL followed by a decrease and a renewed increase from day 9 till OEL was observed. The relatively unchanged plasma level of T4 until day 9 before OEL decreased significantly just before the first oviposition while the T3 level gradually decreased between day 42 and day 9 before OEL, and then increased and again decreased from day 3 before till day 3 after OEL. During sexual maturation the following statistically significant coefficients of correlation between ovarian steroids and T3 were found: E2 vs. T3-->r = -0.551 and P4 vs. T3-->r = -0.373. There was no significant correlation between T and T3 or between the examined steroids and T4. The data obtained indicate that during sexual maturation of the domestic hen there is a negative relationship between the ovary and the thyroid gland.

Animals↗