SERVICES*

Close-up TV News - Prolotheray lecture

Reversing Hypertension

Heavy Metals and all diseases

Close-Up TV News - Dr. Calapai's approach

News 12 Interview: Parkinson’s Disease, Glutathione and Chelation Therapy

News 12 Interview: Platelet-rich plasma therapy

Prolotherapy Interview News 12

News 12 Interview: Diabetes and Weight Loss
Low-Level Human Equivalent Gestational Lead Exposure Produces Supernormal Scotopic Electroretinograms, Increased Retinal Neurogenesis, and Decreased Retinal Dopamine Utilization in Rats *

Background

Postnatal lead exposure in children and animals produces alterations in the visual system primarily characterized by decreases in the rod-mediated (scotopic) electroretinogram (ERG) amplitude (subnormality). In contrast, low-level gestational Pb exposure (GLE) increases the amplitude of scotopic ERGs in children (supernormality).
Objectives

The goal of this study was to establish a rat model of human equivalent GLE and to determine dose–response effects on scotopic ERGs and on retinal morphology, biochemistry, and dopamine metabolism in adult offspring.
Methods

We exposed female Long-Evans hooded rats to water containing 0, 27 (low), 55 (moderate), or 109 (high) ppm of Pb beginning 2 weeks before mating, throughout gestation, and until postnatal day (PND) 10. We measured maternal and litter indices, blood Pb concentrations (BPb), retinal Pb concentrations, zinc concentrations, and body weights. On PND90, we performed the retinal experiments.
Results

Peak BPb concentrations were < 1, 12, 24, and 46 μg/dL in control, low-, moderate- and high-level GLE groups, respectively, at PNDs 0–10. ERG supernormality and an increased rod photoreceptor and rod bipolar cell neurogenesis occurred with low- and moderate-level GLE. In contrast, high-level GLE produced ERG subnormality, rod cell loss, and decreased retinal Zn levels. GLE produced dose-dependent decreases in dopamine and its utilization.
Conclusions

Low- and moderate-level GLE produced persistent scotopic ERG supernormality due to an increased neurogenesis of cells in the rod signaling pathway and/or decreased dopamine utilization, whereas high-level GLE produced rod-selective toxicity characterized by ERG subnormality. The ERG is a differential and noninvasive biomarker of GLE. The inverted U-shaped dose–response curves reveal the sensitivity and vulnerability of the developing retina to GLE.

* Legal Disclaimer: Chelation and Hyperbaric Therapy, Stem Cell Therapy, and other treatments and modalities mentioned or referred to in this web site are medical techniques that may or may not be considered “mainstream”. As with any medical treatment, results will vary among individuals, and there is no implication or guarantee that you will heal or achieve the same outcome as patients herein.

As with any procedure, there could be pain or other substantial risks involved. These concerns should be discussed with your health care provider prior to any treatment so that you have proper informed consent and understand that there are no guarantees to healing.

THE INFORMATION IN THIS WEBSITE IS OFFERED FOR GENERAL EDUCATIONAL PURPOSES ONLY AND DOES NOT IMPLY OR GIVE MEDICAL ADVICE. No Doctor/Patient relationship shall be deemed to have arisen simply by reading the information contained on these pages, and you should consult with your personal physician/care giver regarding your medical treatment before undergoing any sort of treatment or therapy.

Published on 09-01-2010
Authors: Donald A. Fox, Subbarao V. Kala, W. Ryan Hamilton, Jerry E. Johnson, and James P. O'Callaghan
Source: Environ Health Perspect. 2008 May; 116(5): 618-625.