Inflammatory and Morphological Responses of Lactating and Postlactating Rats Following Ozone Exposure: A Comparison of Concentration and Inhaled Dose

Details

• Personal Author:
  Chen LC ; Gunnison AF ; Nadziejko C ; Weideman PA
• Description:
  Ozone (O3) has been shown to elicit an inflammatory response and induce morphological changes in the lung. We have previously shown that rats late in pregnancy and throughout lactation had enhanced inflammatory responses following acute exposure to a high concentration (1.0 ppm) of O3 compared to those of age-matched, virgin female and postlactating rats. This study examined the inflammatory and morphological responses in lactating and postlactating rats following an acute exposure to a range of O3 concentrations. Adult, primiparous Sprague-Dawley CD VAF rats at day 13 of lactation or day-10 postlactation were exposed in barometric plethysmographs to 0, 0.3, 0.5, or 1.0 ppm O3 for 6 hours. Tidal volume and breathing frequency were measured at regular intervals throughout exposure for calculation of inhaled dose. The rats were killed 18 hours after exposure, the right lung was lavaged, and the left lung was fixed for histopathology. Lactating rats had increases in total protein and neutrophils recovered in bronchoalveolar lavage fluid (BALF) compared to postlactating rats. Severity and size of lesioned areas and number of free inflammatory cells in the Jung parenchyma were greater in lactating rats and were concentration dependent for both groups. Alveolar septa! tip thicknesses in the periacinar regions were increased at 1.0ppm only, and there was no difference between groups of rats. Lactating rats had greater minute volumes than postlactating rats at all O3 concentrations. The results of this study show that lactating rats are more sensitive than postlactating rats in selected responses to acute exposures of O3 and suggest that inhaled dose explains a portion of the difference between these groups of animals. [Description provided by NIOSH]
• Subjects:
  Animals Immune System Lung Occupational Health Ozone Respiratory System Safety Toxicology
• Keywords:
  Animal Studies Exposure Assessment Immune Reaction Inhalation Lung Tissue Pulmonary Effects
• ISSN:
  0731-9193
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  New York ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  93-94
• Volume:
  15
• Issue:
  1
• NIOSHTIC Number:
  nn:20060148
• Citation:
  Toxicologist 1995 Mar; 15(1):93-94
• CAS Registry Number:
  Ozone (CAS RN 10028-15-6)
• Federal Fiscal Year:
  1995
• Performing Organization:
  Mount Sinai School of Medicine, New York
• Peer Reviewed:
  False
• Start Date:
  19920701
• Source Full Name:
  The Toxicologist. Society of Toxicology 34th Annual Meeting, March 5-9,1995, Baltimore, Maryland
• End Date:
  19970630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7a32379294d6fe2899c8c182dbe7d20fe3256c53642d42718f5213a179610fe03221c0e19021db482bd577a640adbca46e5ea520e1c842740f979801dda527cf
• Download URL:
  https://stacks.cdc.gov/view/cdc/224151/cdc_224151_DS1.pdf
• File Type:
  [PDF - 283.49 KB ]