Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Gestational changes in hamster adrenal cortex: stereologic and functional studies.

M Nowak1, G G Nussdorfer, K W Nowak

  • 1Department of Histology and Embryology, Poznan Academy of Medicine, Poland.

Research in Experimental Medicine. Zeitschrift Fur Die Gesamte Experimentelle Medizin Einschliesslich Experimenteller Chirurgie
|January 1, 1990
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Cytophysiology of the adrenal zona glomerulosa.

International review of cytology·2010
Same author

Interleukin-1beta Stimulates Corticotropin-Releasing Hormone (CRH) and Adrenocorticotropin (ACTH) Release by Rat Adrenal Gland in Vitro.

Molecular and cellular neurosciences·2009
Same author

Morphometry and mathematical modelling of the capillary-like patterns formed in vitro by bone marrow macrophages of patients with multiple myeloma.

Leukemia·2007
Same author

Fine ultrastructure of chromaffin granules in rat adrenal medulla indicative of a vesicle-mediated secretory process.

Anatomy and embryology·2005
Same author

Preproorexin and orexin receptors are expressed in cortisol-secreting adrenocortical adenomas, and orexins stimulate in vitro cortisol secretion and growth of tumor cells.

The Journal of clinical endocrinology and metabolism·2005
Same author

G protein receptors 7 and 8 are expressed in human adrenocortical cells, and their endogenous ligands neuropeptides B and w enhance cortisol secretion by activating adenylate cyclase- and phospholipase C-dependent signaling cascades.

The Journal of clinical endocrinology and metabolism·2005

Researchers investigated how hamster adrenal glands adapt during pregnancy. They found that while the glands grow and increase their hormone-producing enzyme activity, the actual output of cortisol changes in specific ways. This study highlights that pregnant hamsters have a higher capacity to produce cortisol, though the exact triggers for these changes are still unclear.

Area of Science:

  • Endocrinology research within gestational adrenal cortex physiology
  • Reproductive biology and stereologic analysis

Background:

No prior work had resolved the precise structural and functional adaptations of the adrenal cortex throughout hamster gestation. It was already known that pregnancy induces significant physiological stress and metabolic shifts in mammals. However, the specific cellular mechanisms governing adrenal responsiveness during this period remained largely uncharacterized. Prior research has shown that adrenal weight fluctuates during pregnancy in various rodent models. That uncertainty drove the need for a detailed stereologic investigation into organelle density. This gap motivated an examination of enzymatic activity alongside hormonal output profiles. Scientists previously lacked a comprehensive view of how these morphological changes correlate with systemic steroid levels. This study addresses these unresolved questions by systematically tracking adrenal changes from early to late pregnancy.

Purpose Of The Study:

The study aims to characterize the structural and functional modifications of the adrenal cortex during hamster pregnancy. Researchers sought to determine how morphological changes in organelles relate to altered steroidogenic activity. This investigation addresses the uncertainty regarding the regulation of cortisol production in the absence of pituitary stimulation. The authors intended to quantify the temporal shifts in adrenal weight and enzymatic performance. They aimed to resolve whether structural density changes contribute to the observed hormonal variations. This work clarifies the relationship between systemic hormone levels and local adrenal tissue output. The motivation stems from the need to understand the physiological mechanisms supporting pregnancy-related stress responses. By examining these factors, the team provides a detailed profile of adrenal adaptation throughout the entire gestational timeline.

Keywords:
steroidogenesisendocrine adaptationhamster modelcortisol regulation

Frequently Asked Questions

The researchers propose that the adrenal glands exhibit an enhanced capacity to secrete cortisol. While enzyme activity for 11 beta-hydroxylase and 3 beta-hydroxysteroid dehydrogenase/isomerase rises, the total cortisol content within the gland remains stable throughout the gestational period.

The study utilized stereologic analysis to evaluate the surface densities of mitochondrial cristae and smooth endoplasmic reticulum. These organelles house the enzymes responsible for steroidogenesis, allowing the team to correlate structural integrity with metabolic performance across different gestational stages.

The authors state that the plasma adrenocorticotropic hormone (ACTH) level remains unchanged throughout pregnancy. This stability is necessary to demonstrate that the observed ten-fold increase in blood cortisol concentration is not driven by traditional pituitary-adrenal axis stimulation.

Related Experiment Videos

Main Methods:

The investigators employed a stereologic approach to quantify the surface densities of specific intracellular organelles. They performed enzymatic assays to measure the activity of 11 beta-hydroxylase and 3 beta-hydroxysteroid dehydrogenase/isomerase. The team prepared adrenal homogenates and tissue slices to evaluate steroid production capabilities. Researchers tracked changes in adrenal weight at multiple time points throughout the reproductive cycle. They monitored blood cortisol concentrations using standardized laboratory techniques. The study design included comparing plasma levels of adrenocorticotropic hormone and aldosterone across different gestational stages. This analytical framework allowed for the correlation of morphological data with functional hormonal output. The approach ensured a comprehensive assessment of the adrenal gland's adaptation during the entire pregnancy duration.

Main Results:

The strongest finding indicates that cortisol production in adrenal slices rises gradually throughout the course of pregnancy. Adrenal weight increases promptly, reaching a peak value at day 5 before declining toward term. Enzyme activity for 11 beta-hydroxylase and 3 beta-hydroxysteroid dehydrogenase/isomerase shows significant increases at day 5 and day 10, respectively. Surface densities of mitochondrial cristae and smooth endoplasmic reticulum display no significant changes during the gestational period. Blood cortisol concentration increases approximately ten-fold by the end of pregnancy. Plasma adrenocorticotropic hormone levels remain unchanged despite the substantial rise in systemic cortisol. Plasma aldosterone concentration decreases significantly as the pregnancy progresses. Adrenal homogenates show no significant change in total cortisol content or output despite the observed enzymatic increases.

Conclusions:

The authors propose that the adrenal glands of pregnant hamsters exhibit a heightened potential for cortisol secretion. This synthesis suggests that structural organelle density remains stable despite significant shifts in enzymatic performance. The researchers indicate that the observed rise in cortisol production occurs independently of plasma adrenocorticotropic hormone levels. These findings imply that alternative regulatory pathways likely drive the observed steroidogenic enhancements. The study highlights that plasma aldosterone concentrations decrease significantly as gestation progresses toward term. The authors conclude that the specific factors responsible for these hormonal shifts remain unidentified. This review of the evidence confirms that cortisol output in tissue slices increases gradually during pregnancy. The implications emphasize a complex, non-ACTH-dependent adaptation of the adrenal cortex during the reproductive cycle.

The researchers used adrenal homogenates and adrenal slices to quantify hormone production. Homogenates provided data on total enzyme capacity, whereas slices offered a more physiological model to measure actual cortisol output, revealing a gradual rise that homogenates failed to detect.

The team measured a ten-fold increase in blood cortisol concentration by the end of gestation. In contrast, they observed a significant reduction in plasma aldosterone concentration, highlighting a divergent regulatory response between these two adrenal-derived steroid hormones.

The authors propose that the pregnant hamster's adrenal glands possess an increased ability to produce cortisol. They suggest that the specific factor or factors triggering this enhanced steroidogenic capacity remain unknown, necessitating further investigation into non-ACTH regulatory mechanisms.