Changes in androgen concentrations during puberty and their relation to behaviour in male Saccostomus campestris (Gray 1844), an African rodent

1993 ◽  
Vol 5 (5) ◽  
pp. 577 ◽  
Author(s):  
LM Westlin ◽  
HM Dott
Keyword(s):  
Sexual Development ◽  
Plasma Concentrations ◽  
Reproductive Organs ◽  
Oestrous Cycle ◽  
Plasma Testosterone ◽  
Seminiferous Tubules ◽  
Morphological Development ◽  
Intraindividual Variation ◽  
Adult Females ◽  
Tubule Diameter

Sexual development in male Saccostomus campestris, the pouched mouse, was studied in terms of morphological development and changes in concentrations of plasma testosterone and androstenedione. The interaction of adult females and males following the introduction of a male was observed at all stages of the oestrous cycle. The histology of the reproductive organs is similar to that of other rodents. Measurements of the diameter of the seminiferous tubules and the width of the seminiferous epithelium suggest asymptotic growth but, although the diameter had not reached the asymptote at 70 days of age the epithelial width was close to the calculated asymptote at 55 days of age. Intraindividual variation was no greater than variation between individuals of the same age from 55-70 days. Spermatids were not seen in any animals younger than 45 days, but all animals over 55 days of age had spermatozoa in the epididymis. By 70 days of age, fertile matings were observed. At this stage, the seminiferous tubule diameter was still increasing slowly but plasma concentrations of testosterone and androstenedione had reached adult levels; at no time was the concentration of testosterone greater than androstenedione. The males were never aggressive towards females; however, they were severely attacked by females at all stages of the oestrous cycle except pro-oestrus. Only rarely did males show aggression to other males.

INFLUENCE OF METYRAPONE ON PLASMA CONCENTRATIONS OF TESTOSTERONE AND ANDROSTENEDIONE IN MAN

1971 ◽  
Vol 68 (3) ◽  
pp. 576-584 ◽  
Author(s):  
K. O. Nilsson ◽  
B. Hökfelt
Keyword(s):  
Body Weight ◽  
Male Patient ◽  
Gradual Increase ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Normal Males ◽  
A Minor ◽  
Secondary Hypogonadism

ABSTRACT Metyrapone was administered either orally, 750 mg every four h, in a total of six doses, or intravenously 30 mg per kg body weight as a four h infusion. In three males with normal endocrine functions, metyrapone given orally or intravenously induced a fall in plasma testosterone and an elevation of androstenedione within 2–8 h. When metyrapone was administered to a patient given dexamethasone to suppress endogenous ACTH production, the androstenedione levels did not alter whereas the testosterone levels showed a slight, transient decrease. In two normal females metyrapone administration was followed by a marked increase in plasma androstenedione whereas testosterone showed only a minor, gradual increase. In one male patient with Addison's disease the basal plasma testosterone was normal whereas the level of androstenedione was low. Following metyrapone intravenously, there was a slight suppression of plasma testosterone but no change in the androstenedione concentration. In one patient with primary hypogonadism, two with secondary hypogonadism and two with Klinefelter's syndrome the plasma testosterone was low under basal conditions and did not change following metyrapone. Basal plasma androstenedione was within the range for normal males and increased markedly following metyrapone in all the cases.

FSH AND LH LEVELS IN THE INTACT AND UNILATERALLY OVARIECTOMIZED CYCLING RAT

1972 ◽  
Vol 69 (2) ◽  
pp. 267-280 ◽  
Author(s):  
Richard D. Peppler
Keyword(s):  
Plasma Concentrations ◽  
Follicular Development ◽  
Slight Modification ◽  
Oestrous Cycle ◽  
Successive Cycle ◽  
Unilateral Ovariectomy ◽  
Subsequent Cycle ◽  
Intact Rats

ABSTRACT Intact 5-day cycling rats were killed between 8–10 a. m. on each day of the oestrous cycle; experimental rats were unilaterally ovariectomized (ULO) at 9 a. m. on day 1 (oestrus) and killed between 8 and 10 a. m. on days 2, 3, 4 or 1 of the subsequent cycle. Pituitary and plasma concentrations of FSH and LH were measured in both groups of rats. Pituitary FSH concentration was measured by the Steelman-Pohley method with slight modification; plasma FSH by the Igarashi-McCann assay and pituitary and plasma LH concentration by the OAAD method. In intact rats, pituitary FSH values remained constant for the first three days of the cycle, increased on day 4 and reverted to early cycle values by day 5. Plasma FSH increased between days 2 and 3 and days 5 and 1. Pituitary LH concentration remained the same for days 1 and 2; increased two-fold on days 3 and 4, and increased further by day 5. Plasma LH increased between days 2 and 3; other differences between successive cycle days were not apparent. Following ULO on day 1, pituitary FSH increased steadily, but not significantly, for the remaining cycle. Plasma FSH did not change from day 2 through day 1 of the subsequent cycle. Pituitary LH remained low on day 2, increased sharply by day 3 and decreased (50 %) by day 4. Plasma LH also increased between days 2 and 3. Other differences between successive days following unilateral ovariectomy on day 1 were not apparent. Correlation of gonadotrophin activity with follicular development suggests that the mechanism of compensatory ovulation in the rat may be one of an increase in time of exposure to a constant gonadotrophic level for the duration of the oestrous cycle rather than to increased levels of the gonadotrophin.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Plasma Concentrations ◽  
External Genitalia ◽  
Oestrous Cycle ◽  
Phascolarctos Cinereus ◽  
Pregnant Females ◽  
Peripheral Plasma ◽  
The Mean ◽  
High Concentrations

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

scholarly journals Intraoperative assessment of tubules in predicting microdissection testicular sperm extraction outcome in men with Sertoli cell-only syndrome

2018 ◽  
Vol 47 (2) ◽  
pp. 722-729 ◽  
Author(s):  
Yang Yu ◽  
Qi Xi ◽  
Ruixue Wang ◽  
Hongguo Zhang ◽  
Leilei Li ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Follicle Stimulating Hormone ◽  
Seminiferous Tubules ◽  
Testicular Sperm Extraction ◽  
Testicular Sperm ◽  
Sperm Retrieval ◽  
Intraoperative Assessment ◽  
Retrieval Rate ◽  
Surgical Suture ◽  
Tubule Diameter

Objective This study aimed to assess the value of measuring the tubule diameter during microdissection testicular sperm extraction (micro-TESE) in predicting outcomes in patients with Sertoli cell-only syndrome (SCOS). Methods Fifty-six consecutive patients with SCOS were included. Patients were classified into two groups on the basis of the diameter of seminiferous tubules measured against 5/0 surgical suture (≥100 µm or <100 µm). Results The sperm retrieval rate (SRR) in men with a tubule diameter ≥100 µm was significantly lower than that in those with <100 µm (3.1% vs. 25.0%). The SRR from the contralateral testis in men with a tubule diameter ≥100 µm was lower than that in those with <100 µm (0% vs. 14.3%). Men with a tubule diameter ≥100 µm had a significantly larger testis and lower follicle-stimulating hormone levels than did men with <100 µm (8.1 ± 2.4 vs. 5.3±1.8 mL, 19.9 ± 9.7 vs. 25.9 ± 7.1 mIU/mL, respectively). Conclusions The diameter of tubules is a useful predictor for a successful SRR in men with SCOS. Intraoperative assessment of homogeneous large tubules allows some men to perform a limited (superficial) contralateral micro-TESE after no spermatozoa are initially identified.

PROLONGED RELEASE BY DIOESTROUS RATS OF FOLLICLE-STIMULATING HORMONE DURING THE PERIOD OF OVULATION INDUCED BY LUTEINIZING HORMONE RELEASING HORMONE

1979 ◽  
Vol 81 (1) ◽  
pp. 109-118 ◽  
Author(s):  
SHUJI SASAMOTO ◽  
SHIGEO HARADA ◽  
KAZUYOSHI TAYA
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Concentrations ◽  
High Plasma ◽  
Oestrous Cycle ◽  
Prolonged Release ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Follicular Maturation ◽  
Lh Rh ◽  
Premature Ovulation

When 1·0 μg luteinizing hormone releasing hormone (LH-RH) was given i.v. three times at 1 h intervals from 17.00 to 19.00 h on the day of dioestrus (day 0) to regular 4 day cyclic rats, premature ovulation was induced the next morning (day 1) with the number of ova present comparable to normal spontaneous ovulation. The next spontaneous ovulation occurred on the morning of day 5, 4 days after premature ovulation induced by LH-RH. Plasma concentrations of FSH and LH showed transient rises and falls within 1 h of administration of LH-RH; concentrations of FSH in the plasma decreased from 20.00 h on day 0 but markedly increased again from 23.00 h on day 0 to 02.00 h on day 1 and these high levels persisted until 14.00 h on day 1, with only a small increase of plasma LH during this period. The duration of increased FSH release during premature ovulation induced by LH-RH treatment was 6 h longer than the FSH surge occurring after administration of HCG on day 0. Surges of gonadotrophin were absent on the afternoon of day 1 (the expected day of pro-oestrus) and the surges characteristic of pro-oestrus occurred on the afternoon of day 4 and ovulation followed the next morning. The pituitary content of FSH did not decrease despite persisting high plasma levels of FSH during premature ovulation induced by either LH-RH or HCG on day 0. The changes in uterine weight indicated that the pattern of oestrogen secretion from the day of premature ovulation induced by LH-RH to the day of the next spontaneous ovulation was similar to that of the normal 4 day oestrous cycle. When 10 i.u. HCG were given on day 0, an increase in oestrogen secretion occurred on day 2, 1 day earlier than in the group given LH-RH on day 0. This advancement of oestrogen secretion was assumed to be responsible for the gonadotrophin surges on day 3. Similar numbers of fully developed follicles were found by 17.00 h on day 2 after premature ovulation induced by either LH-RH or HCG, suggesting that the shorter surge of FSH during premature ovulation induced by HCG had no serious consequences on the initiation of follicular maturation for the succeeding oestrous cycle in these rats. Administration of LH-RH on day 0 had no direct effect on the FSH surge during premature ovulation. Secretory changes in the ovary during ovulation may be responsible for this prolonged selective release of FSH.

scholarly journals Overexpression of the Matrix Metalloproteinase Matrilysin Results in Premature Mammary Gland Differentiation and Male Infertility

1998 ◽  
Vol 9 (2) ◽  
pp. 421-435 ◽  
Author(s):  
Laura A. Rudolph-Owen ◽  
Paul Cannon ◽  
Lynn M. Matrisian
Keyword(s):  
Matrix Metalloproteinase ◽  
Transgenic Animals ◽  
Reproductive Organs ◽  
Mammary Development ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Wild Type ◽  
The Matrix

To examine the role of matrilysin (MAT), an epithelial cell-specific matrix metalloproteinase, in the normal development and function of reproductive tissues, we generated transgenic animals that overexpress MAT in several reproductive organs. Three distinct forms of human MAT (wild-type, active, and inactive) were placed under the control of the murine mammary tumor virus promoter/enhancer. Although wild-type, active, and inactive forms of the human MAT protein could be produced in an in vitro culture system, mutations of the MAT cDNA significantly decreased the efficiency with which the MAT protein was produced in vivo. Therefore, animals carrying the wild-type MAT transgene that expressed high levels of human MAT in vivo were further examined. Mammary glands from female transgenic animals were morphologically normal throughout mammary development, but displayed an increased ability to produce β-casein protein in virgin animals. In addition, beginning at approximately 8 mo of age, the testes of male transgenic animals became disorganized with apparent disintegration of interstitial tissue that normally surrounds the seminiferous tubules. The disruption of testis morphology was concurrent with the onset of infertility. These results suggest that overexpression of the matrix-degrading enzyme MAT alters the integrity of the extracellular matrix and thereby induces cellular differentiation and cellular destruction in a tissue-specific manner.

Pituitary and gonadal responses to the long-term pulsatile administration of gonadotrophin-releasing hormone in fetal fetal sheep

1997 ◽  
Vol 153 (3) ◽  
pp. 385-391 ◽  
Author(s):  
G B Thomas ◽  
A N Brooks
Keyword(s):  
Plasma Concentrations ◽  
Reproductive Function ◽  
Inverse Correlation ◽  
Experimental Period ◽  
Immediate Release ◽  
Late Gestation ◽  
Plasma Testosterone ◽  
Fetal Sheep ◽  
Pulsatile Administration

Abstract The fetal hypothalamo–pituitary–gonadal axis reaches a peak in activity at mid-gestation and this is followed by a period of suppression which persists until the onset of puberty. The decline in gonadotrophic activity during late gestation is thought to reflect the maturation of central and peripheral feedback signals. In order to establish if sustained pituitary responsiveness is rate limiting to the reinstatement of reproductive function, we have examined the endocrine consequences of repeated pulsatile GnRH administration to male and fetal sheep during late gestation. Beginning on day 121 of gestation (term=145 days) chronically catheterized fetal sheep were given i.v. pulses of either 500 ng GnRH or saline every 2 h for 14 days. Pituitary and gonadal responses were assessed by measuring changes in plasma concentrations of LH, FSH, inhibin and testosterone (in male fetuses) in response to the first pulse of GnRH on day 1 and to the corresponding pulse on days 4, 7, 10 and 14. In response to the first pulse of GnRH there was an immediate release of LH, with the peak response being significantly (P<0·01) greater than on subsequent days. In male fetuses each pulse of LH was followed by a rise in plasma testosterone concentrations within 40–60 min. The amplitude of these testosterone responses increased significantly (P<0·01) after 9 days of treatment despite a decline in the plasma LH response. Basal FSH concentrations increased progressively (P<0·05) during pituitary stimulation with GnRH in both male and female fetuses. Immunoreactive inhibin concentrations were significantly (P<0·05) higher in males than in females, and there was a gradual increase throughout the experimental period irrespective of treatment. We observed no inverse correlation between inhibin and FSH concentrations. These data show that pulsatile administration of GnRH to fetal sheep during late gestation results in sustained re-activation of pituitary–gonadal function. The decline in fetal gonadotrophins, which is a characteristic feature of late gestation, is therefore likely to result from inadequate GnRH secretion from the fetal hypothalamus rather than an inhibition of pituitary function by peripheral feedback signals. Journal of Endocrinology (1997) 153, 385–391

scholarly journals The reproductive hormone cycle of adult female American alligators from a barrier island population

Reproduction ◽  
2014 ◽  
Vol 147 (6) ◽  
pp. 855-863 ◽  
Author(s):  
Heather J Hamlin ◽  
Russell H Lowers ◽  
Satomi Kohno ◽  
Naoko Mitsui-Watanabe ◽  
Haruna Amano ◽  
...  
Keyword(s):  
Adult Female ◽  
Plasma Concentrations ◽  
Barrier Island ◽  
Reproductive Activity ◽  
Plasma Testosterone ◽  
Island Population ◽  
Moderate Increase ◽  
Random Intervals ◽  
American Alligators ◽  
Kennedy Space

Comparatively, little data are available detailing the geographic variation that exists in the reproductive endocrinology of adult alligators, especially those living in barrier islands. The Merritt Island National Wildlife Refuge (MI) is a unique barrier island environment and home to the Kennedy Space Center (FL, USA). Seasonal patterns of sex steroids were assessed in adult female American alligators from MI monthly from 2008 to 2009, with additional samples collected at more random intervals in 2006, 2007, and 2010. Plasma 17β-estradiol and vitellogenin concentrations peaked in April, coincident with courtship and mating, and showed patterns similar to those observed in adult female alligators in other regions. Plasma concentrations of progesterone, however, showed patterns distinctly different than those reported for alligator populations in other regions and remained relatively constant throughout the year. Plasma DHEA peaked in July around the time of oviposition, decreased in August, and then remained constant for the remaining months, except for a moderate increase in October. Circulating concentrations of DHEA have not been previously assessed in a female crocodilian, and plasma concentrations coincident with reproductive activity suggest a reproductive and/or behavioral role. Interestingly, plasma testosterone concentrations peaked in May of 2008, as has been shown in female alligator populations in other regions, but showed no peak in 2009, demonstrating dramatic variability from year to year. Surveys showed 2009 to be particularly depauperate of alligator nests in MI, and it is possible that testosterone could serve as a strong indicator of breeding success.

scholarly journals A first observation of spermatogenesis in mature male scalloped hammerheads (Sphyrna lewini) from Zinkwazi, KwaZulu-Natal, South Africa

2020 ◽  
Author(s):  
Helené J. Coetzee ◽  
Kristina Naidoo ◽  
Ina Wagenaar
Keyword(s):  
South Africa ◽  
Reproductive Organs ◽  
Mature Male ◽  
Seminiferous Tubules ◽  
Stages Of Development ◽  
Biometric Data ◽  
Sphyrna Lewini ◽  
Histological Assessment ◽  
Scalloped Hammerhead ◽  
Kwazulu Natal

Abstract Sharks are not only threatened, but also have a low fecundity as they are being overfished. The shark family, Sphyrnidae, consists of nine species of which three are found in South African oceans. One of the three Sphyrnidae species, the scalloped hammerhead (Sphyrna lewini) are the most common, but their biology and mode of reproduction are not extensively studied in terms of their reproductive biology. The aim of this study was to describe the germ cell development in the testes of sexually mature male scalloped hammerheads. Three individual male S. lewini were caught at Zinkwazi, KwaZulu-Natal, South Africa. The sharks and their reproductive organs were weighed and measured to collect the biometric data for the condition factor and the gonado-somatic index. Following standard necropsy, the testes were fixed in Bouin’s solution and processed for histological assessment. The histological assessment revealed that the testes of S. lewini consist of seminiferous tubules which form part of a larger lobular structure with germ cells in different stages of development, from spermatogonia to mature spermatozoa. Seven stages of development were identified during the process of spermatogenesis, similar to what has been described for elasmobranchs. In conclusion, this study provides evidence that the testes of S. lewini are diametrical and polyspermatocystic and conforms to the testes structure of elasmobranch males.

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