Postnatal Development of Reproductive System in Male Guinea Pigs and Its Relation to Testis Hormone Secretion

1939 ◽  
Vol 12 (3) ◽  
pp. 256-267 ◽  
Author(s):  
E. Duane Sayles
Keyword(s):  
Postnatal Development ◽  
Reproductive System ◽  
Guinea Pigs ◽  
Hormone Secretion

Metabolic Patterns of Several Tissues of Rabbits and Guinea Pigs during Postnatal Development

Neonatology ◽  
1973 ◽  
Vol 22 (3-4) ◽  
pp. 201-221 ◽  
Author(s):  
W. Isselhard ◽  
J.H. Fischer ◽  
H. Kapune ◽  
W. Stock
Keyword(s):  
Postnatal Development ◽  
Guinea Pigs

Growth hormone secretion in the guinea-pig

1990 ◽  
Vol 124 (3) ◽  
pp. 371-380 ◽  
Author(s):  
B. Gabrielsson ◽  
K. M. Fairhall ◽  
I. C. A. F. Robinson
Keyword(s):  
Growth Hormone ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Physiological Control ◽  
Gh Secretion ◽  
Dose Dependent Fashion ◽  
Growth Promoting ◽  
Dose Dependent

ABSTRACT The guinea-pig is unusual in that it continues to grow at a normal rate after hypophysectomy. Although its pituitary gland appears to contain a GH, this has not been isolated or characterized, and nothing is known about its secretion or physiological control. We have identified guinea-pig GH, established a sensitive heterologous radioimmunoassay and adapted our automatic blood microsampling method to study spontaneous GH secretion in this species. In male guinea-pigs, GH is released in an episodic pattern, reminiscent of the rat. Large multicomponent pulses of GH secretion occur every 3–4 h between periods of low or undetectable GH release, whereas most females showed a more uniform pulsatile pattern with pulses every 1–2 h. GH was released in response to GH-releasing factor (GRF) injections (2, 10 or 20 μg [Nle27]-GRF(1–29)NH2) in a dose-dependent fashion, and i.v. infusion of somatostatin (50 μg/h) blocked spontaneous GH pulses, eliciting a rebound release (from 2·0±0·8 (s.e.m.) to 36±17 μg/l 30 min after stopping the infusion). Infusions of a GH-releasing hexapeptide (100 or 400 μg/h for 4 h) also released GH. These results provide the first description of the pattern of GH release in the guinea-pig, and suggest that the striking episodic pattern is controlled by the same hypothalamic peptides that regulate GH in other species. Since the guinea-pig grows well in the absence of GH, this species may use GH for its metabolic, rather than growth-promoting actions. The guinea-pig may well prove a useful model, now that methods are available for studying its endogenous GH secretion. Journal of Endocrinology (1990) 124, 371–380

Postnatal development of the reproductive system in the grey short-tailed opossum, Monodelphis domestica

2004 ◽  
Vol 208 (2) ◽  
pp. 121-133 ◽  
Author(s):  
S. Mackay ◽  
Q. Xie ◽  
S. L. Ullmann ◽  
D. P. Gilmore ◽  
A. P. Payne
Keyword(s):  
Postnatal Development ◽  
Reproductive System ◽  
Monodelphis Domestica

scholarly journals Major Royal Jelly Proteins Accelerate Onset of Puberty and Promote Ovarian Follicular Development in Immature Female Mice

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1145-1145
Author(s):  
Lirong Shen ◽  
Xin Liu ◽  
Yong Chen ◽  
Fangxiong Shi ◽  
Chao-Qiang Lai
Keyword(s):  
Reproductive System ◽  
Royal Jelly ◽  
Hormone Secretion ◽  
Follicular Development ◽  
Serum Estradiol ◽  
Immature Female ◽  
Female Mice ◽  
Estrogenic Effect ◽  
Ovarian Follicular Development ◽  
Estradiol Levels

Abstract Objectives Estrogen plays an important role in for growth and development of reproductive system in female. The major royal jelly (RJ) has a significant estrogenic-like effect for many female animals. The major RJ proteins (MRJPs) are the central constituents responsible for the physiological activities of RJ. In recent years, we have found that MRJPs possesses functions to increase fecundity associated with estrogenic effect in Drosophila. However, if MRJPs are the specific active ingredient mediating estrogenic effect of RJ and related action mechanism in mammalians remains unclear. Methods Neonatal immature female mice (FC) were divided into four groups fed MRJPs with doses of 0, 125, 250 and 500 mg/kg/body weight (M125, M250 and M500), respectively. The freeze-dried MRJPs powder was administrated daily for 45 consecutive days. The effects of MRJPs on the puberty onset, ovarian follicular development and serum estradiol levels in FC were evaluated. Results The times of estrus in M125, M250 and M500 were accelerated by 10.7%, 15.5% and 10.7%, the ovarian index of M125 and M250 and M500 were increased by 26.8% and 32.1% and 1.7%. The number of secondary follicles in M125 and M250 and M500 were increased by 50.7%,78.8% and 38.6%, the Graafian follicles in M125 and M250 and M500 were increased by 600.0% and 774.0% and 150.0%. M500 induced multi-oocyte follicles. The serum estradiol levels of M125, M250 and M500 were increased by 47.1%, 64.9% and 31.1%, the action of MRJPs raising hormone secretion level is mainly via upregulating expression of ERβ gene. Antioxidant parameters of ovarian tissue showed that the malondialdehyde levels in M125 and M250 were decreased, the superoxide dismutase activities and glutathione peroxidase activities in M125 and M250 were increased, respectively. Conclusions Oral administration of MRJPs may accelerate onset of puberty and promote follicular development in immature FM. The reproductive performance promotion of MRJPs was associated with raising estrogenic activity and antioxidant potential to reproductive system, upregulating expression of ERβ gene to raise hormone secretion and promote ovary development in FM. Funding Sources The National Natural Science Foundation of China and US Department of Agriculture, Agriculture Research Service.

The comparative aspects of hystricomorph subplacenta: potential endocrine organ

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Maria Angelica Miglino ◽  
Gustavo de Sá Schiavo Matias ◽  
Nathia Nathaly Rigoglio ◽  
Jessica Borghesi ◽  
Taís Harumi de Castro Sasahara ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Hormone Secretion ◽  
Chorionic Villus ◽  
Secretory Activity ◽  
Steroidogenic Enzymes ◽  
Unusual Structure ◽  
Hormone Synthesis ◽  
Trophoblastic Cells ◽  
Considerable Controversy ◽  
Near Term

Abstract Background The placenta of hystricomorph rodents, lagomorphs and some primates includes an unusual structure, termed a subplacenta, which essentially consists of trophoblastic cells located deep to the central implantation site within the area of decidualization. It has been suggested that the subplacenta is functionally important, although considerable controversy remains on the issue. In this context, our objective was to compare the architecture and structure of the subplacentas of different hystricomorph species, to investigate the possibility that it is active in hormone synthesis. Methods In total, the placentas of 3 capybaras (Hydrochaeris hydrochaeris), 2 pacas (Agouti paca), 5 agoutis (Dasyprocta leporina), 5 rock cavies (Kerodon rupestris) and 3 guinea pigs (Cavia porcellus) at different stages of pregnancy (early, middle and near term) were used for gross and microscopic examination. This included the preparation of latex injection casts, immunohistochemistry for steroidogenic enzymes, scanning and transmission electron microscopy. Tissue steroid concentrations were also determined. Results The gross morphology and microvascular arrangement of the subplacentas were similar among the hystricomorphs studied including ultra-structural verification of cytotrophoblast and syncytiotrophoblast in all species. In guinea pigs, trophoblast cells exhibited characteristics consistent with intense metabolic and secretory activity in general. However, immuno-histochemical evidence also indicated that subplacental trophoblast expressed key steroidogenic enzymes, mainly in the chorionic villus region, consistent with tissue steroid concentrations. Conclusions The subplacentas within placentas of hystricomorph rodent species are structurally similar and, in guinea pigs, have potential for steroid hormone secretion from, at least the early stages of pregnancy.

β-Glucuronidase Activity in the Jejunum and Ileum of Mice, Rabbits and Guinea Pigs During their Postnatal Development

Neonatology ◽  
1965 ◽  
Vol 8 (1) ◽  
pp. 30-35 ◽  
Author(s):  
V. Jirsová ◽  
O. Koldovský ◽  
A. Heringová ◽  
J. Hošková
Keyword(s):  
Postnatal Development ◽  
Guinea Pigs ◽  
Glucuronidase Activity

scholarly journals Impact of Age on the Male Reproductive System from the Pathologist’s Perspective

2016 ◽  
Vol 45 (1) ◽  
pp. 195-205 ◽  
Author(s):  
Catherine A. Picut ◽  
Amera K. Remick
Keyword(s):  
Postnatal Development ◽  
Reproductive System ◽  
Reproductive Organs ◽  
Male Reproductive System ◽  
Laboratory Animals ◽  
Large Animal ◽  
Age Related ◽  
Organ Systems ◽  
Microscopic Evaluation ◽  
Tissue Changes

Age, and in particular young age, can significantly impact the response to toxicants in animals and can greatly influence the interpretation of tissue changes by the toxicologic pathologist. Although this applies to multiple organ systems, the current review focuses on the male reproductive system. When performing microscopic evaluation of male reproductive organs, the toxicologic pathologist must be aware of the dynamic changes in histomorphology, predominantly driven by timed hormonal alterations, at various life stages. Specific challenges pathologists face are understanding the appearance of male reproductive tissues throughout the neonatal, infantile, and juvenile developmental periods, recognizing when normal looks abnormal during tissue development, defining sexual maturity, and working with high interanimal variability in maturation rate and histologic appearance in developing large laboratory animals, such as nonhuman primates, dogs, and pigs. This review describes postnatal development of the male reproductive system in the rat, demonstrates how assessing toxicity during a defined window of postnatal development in the rat may improve definition of toxicant timing and targets, and discusses challenges associated with the interpretation of toxicity in immature large animal species. The emphasis is on key age-related characteristics that influence the interpretation of tissue changes by the toxicologic pathologist.

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