• About
  • Masthead
  • License Content
  • Advertise
  • Submit Press Release
  • RSS/Email List
  • Write for us
  • Contact us
2 Minute Medicine
No Result
View All Result

No products in the cart.

SUBSCRIBE
  • Specialties
    • Cardiology
    • Chronic Disease
    • Dermatology
    • Emergency
    • Endocrinology
    • Gastroenterology
    • Imaging and Intervention
    • Infectious Disease
    • Nephrology
    • Neurology
    • Obstetrics
    • Oncology
    • Ophthalmology
    • Pediatrics
    • Preclinical
    • Psychiatry
    • Public Health
    • Pulmonology
    • Rheumatology
    • Surgery
  • Wellness
  • Classics™
    • 2MM+ Online Access
    • Paperback and Ebook
  • Rewinds
  • Visual
  • Partners
    • License Content
    • Submit Press Release
    • Advertise with Us
  • AccountLog-in/out
    • Subscribe
    • Sign-in
    • My account
2 Minute Medicine
  • Specialties
    • Cardiology
    • Chronic Disease
    • Dermatology
    • Emergency
    • Endocrinology
    • Gastroenterology
    • Imaging and Intervention
    • Infectious Disease
    • Nephrology
    • Neurology
    • Obstetrics
    • Oncology
    • Ophthalmology
    • Pediatrics
    • Preclinical
    • Psychiatry
    • Public Health
    • Pulmonology
    • Rheumatology
    • Surgery
  • Wellness
  • Classics™
    • 2MM+ Online Access
    • Paperback and Ebook
  • Rewinds
  • Visual
  • Partners
    • License Content
    • Submit Press Release
    • Advertise with Us
  • AccountLog-in/out
    • Subscribe
    • Sign-in
    • My account
SUBSCRIBE
2 Minute Medicine
Subscribe
Home All Specialties Chronic Disease

Growth hormone releasing hormone (GHRH) agonists protects against diabetic retinopathy in animal model

byCorinne FoleyandRadhika Agarwal
January 18, 2018
in Chronic Disease, Endocrinology, Ophthalmology, Preclinical
Reading Time: 3 mins read
0
Share on FacebookShare on Twitter

1. GHRH and GHRH receptor levels are decreased in diabetic rats and humans.

2. Administration of GHRH agonists to diabetic rats reversed signs of diabetic retinopathy.

Evidence Rating Level: 2 (Good)

Study Rundown: Diabetic retinopathy is the main cause of blindness in the Western world. However, effective treatment for this condition remains limited, in part due to a lack of understanding as to how this condition develops. The growth hormone axis has been implied in retinal ganglion cell development and activity. Researchers at the Medical College of Georgia examined levels of growth hormone and growth hormone receptor in the retinas of diabetic rats and patients, and discovered that the growth hormone axis was downregulated relative to wild-type controls. Based on these findings, the authors hypothesized that treating these mice with growth hormone agonists might restore retinal integrity and function.

When diabetic and non-diabetic mice were treated with GHRH agonists, multiple structural and functional changes suggested reversal of pathologic features typically associated with diabetic retinopathy. For instance, retinal thickness decreased following treatment with the agonist. Furthermore, retinal cell death decreased following treatment, likely due to decreased production of reactive oxygen species. Gliosis and inflammation were also reduced in the presence of the GHRH agonist. Finally, the agonist appeared to have vasculoprotective effects as well, increasing the integrity of retinal blood vessels. Furthermore, GHRH antagonists resulted in worsening of retinal morphology.

These animal studies suggest GHRH agonists may protect against the development of diabetic retinopathy. Although the toxicity of this drug and optimal dose for administration still need to be determined, these studies highlight a new potential therapeutic for diabetic patients.

Click to read the study in PNAS

RELATED REPORTS

The ACCORD trial: Intensive glucose control associated with increased mortality [Classics Series]

Increases in muscle-strengthening activities may reduce mortality risk and certain diseases

Associations of dietary patterns and lifestyle modifications with glycemic control in diabetic patients

Relevant Reading: Diabetic retinopathy: research to clinical practice

In-Depth [animal study]: Retinas from streptozotocin-induced diabetic (STZ) rats and post-mortem human diabetic donors were obtained and qPCR performed to evaluate mRNA expression of GHRH and western blot performed to evaluate expression of its receptor (GHRH-R). A significant decrease in both GHRH and GHRH-R was noted in both diabetic mice and humans compared to normoglycemic controls (p< 0.01). STZ-rats were then treated with 15 ug/kg MR-409, a GHRH agonist, for 6 weeks and the retinas obtained for analysis. H&E staining of retinas from control rats along with treated and untreated STZ-rats revealed that whereas diabetes decreased the thickness of the retina, treatment with MR-409 normalized its structure. Because the decreased thickness of the retina in diabetes is typically due to increased retinal cell death, TUNEL staining was used to identify dying cells, revealing an increase in TUNEL-positive nuclei in STZ-rats and a reduction following treatment.

To assess retinal cell injury due to oxidation typically seen in diabetes, the reactive oxygen species 3-nitrotyrosine and 4-hydroxynonenal were evaluated using immunohistochemistry. These studies revealed a protective effect of MR-409 through the reduction of reactive oxygen species expression. Gliosis and inflammation in the retina were then evaluated due to these typical findings in retinas of diabetic patients and rats. To evaluate the induction of gliosis, immunohistochemistry was used to assess ICAM-1 and GFAP expression, molecules found to be upregulated with hyperglycemia. Treatment with MR-409, however, decreased these markers of gliosis. Additionally, using ELISA to evaluate cytokine production, a decrease of pro-inflammatory cytokines was noted following treatment along with an increase in anti-inflammatory cytokines (p< 0.05).

Finally, fundoscopy was performed on the rats to visualize the vascular integrity of the retinal blood vessels. Whereas the untreated STZ-rats demonstrated elevated dye extravasation due to hyperglycemia, this was significantly decreased following treatment (p<0.01) suggestive of improved vascular integrity.

Image: PD

©2018 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.

Tags: diabetes
Previous Post

2 Minute Medicine Rewind January 15, 2018

Next Post

Percutaneous patent foramen ovale closure is superior to medical treatment alone in preventing recurrent stroke

RelatedReports

Classics Series, Landmark Trials in Medicine
Emergency Classics

The ACCORD trial: Intensive glucose control associated with increased mortality [Classics Series]

May 4, 2022
Exercise improves aromatase inhibitor-induced arthralgia in breast cancer survivors
Cardiology

Increases in muscle-strengthening activities may reduce mortality risk and certain diseases

May 3, 2022
Chronic Disease

Associations of dietary patterns and lifestyle modifications with glycemic control in diabetic patients

April 29, 2022
Filtered-sunlight may effectively treat neonatal jaundice in resource-poor settings
Cardiology

Light exposure during sleep may alter glucose metabolism and impair cardiometabolic function

April 19, 2022
Next Post
Intensive rehabilitation not superior to traditional therapy for arm function after stroke

Percutaneous patent foramen ovale closure is superior to medical treatment alone in preventing recurrent stroke

Normal tissue BRCA1 methylation associated with risk for high-grade ovarian cancer

Interstitial lung abnormalities linked to greater risk of all-cause mortality

Thyroid hormone supplementation may be a promising treatment for idiopathic pulmonary fibrosis [PreClinical]

License Our Award-Winning Physician-Written Medical News and Visual Abstracts

2 Minute Medicine is the leading authoritative medical news licensing service, and the only with reports written by practicing doctors.

LICENSE CONTENT

Get 2MM+ Premium Access

No ads & unlimited access to all current reports, over 9000 searchable archived reports, visual abstracts, Weekly Rewinds, and the online edition of The Classics Series™ textbook.

Subscription Options
2 Minute Medicine

2 Minute Medicine® is an award winning, physician-run, expert medical media company. Our content is curated, written and edited by practicing health professionals who have clinical and scientific expertise in their field of reporting. Our editorial management team is comprised of highly-trained MD physicians. Join numerous brands, companies, and hospitals who trust our licensed content.

Recent Reports

  • #VisualAbstract: Bimekizumab shows a favourable 2-year safety profile in patients with moderate to severe plaque psoriasis
  • Medical cannabis provides little improvement to sleep in chronic pain patients
  • Alzheimer disease in individuals with Down syndrome has similar variability in age of onset and mortality rate as autosomal dominant forms
License Content
Terms of Use | Disclaimer
Cookie Policy
Privacy Statement (EU)
Disclaimer

© 2021 2 Minute Medicine, Inc. - Physician-written medical news.

  • Specialties
    • Cardiology
    • Chronic Disease
    • Dermatology
    • Emergency
    • Endocrinology
    • Gastroenterology
    • Imaging and Intervention
    • Infectious Disease
    • Nephrology
    • Neurology
    • Obstetrics
    • Oncology
    • Ophthalmology
    • Pediatrics
    • Preclinical
    • Psychiatry
    • Public Health
    • Pulmonology
    • Rheumatology
    • Surgery
  • Wellness
  • Classics™
    • 2MM+ Online Access
    • Paperback and Ebook
  • Rewinds
  • Visual
  • Partners
    • License Content
    • Submit Press Release
    • Advertise with Us
  • Account
    • Subscribe
    • Sign-in
    • My account

© 2021 2 Minute Medicine, Inc. - Physician-written medical news.