Morphological and functional aspects of the aortic depressor nerve in diabetic rats

• Published in: The FASEB journal Vol. 21; no. 5; p. A473
• Main Authors: Carmo, Jussara Marcia do, Castania, Jaci Airton, Fazan, Valeria Paula Sassoli, Fazan, Rubens, Salgado, Helio Cesar
• Format: Journal Article
• Language: English
• Published: Federation of American Societies for Experimental Biology 01-04-2007
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.21.5.A473-a

Functional and morphological aspects of the aortic depressor nerve (ADN) were investigated in acute (5 days) and chronic (120 days) streptozotocin (STZ) induced diabetic rats. Arterial pressure (AP) and ADN activity were continuously recorded under anesthesia. After basal recording, AP was changed to assess the entire range of ADN activity. Baroreceptor gain was examined either by the first derivative of AP vs. ADN activity curve, fitted by sigmoidal regression, or by cross‐spectral analysis between spontaneous oscillations of AP and ADN activity. Afterwards, ADN was collected for morphometric analysis. Gain of aortic baroreceptors (%basal/mmHg), evaluated by AP vs. ADN activity curves, was similar between control and diabetic rats at 5 (5±0.5 vs. 4.5±1) or 12 days after STZ (4.0±0.5 vs. 3.5±0.7). Cross spectral analysis also revealed similar baroreceptor gain between diabetic and control rats at 5 (2.7±0.5 vs. 2.9±0.2) or 120 days (3.4±0.6 vs. 2.8±0.2). Chronic diabetic rats presented a smaller ADN fascicular area (0.9±0.1 vs. 1.4±0.1 μm2) and a smaller myelin area (2.0±0.1 vs. 3.8±0.15 μm2). The number of fibers and the area of myelinated axons were found similar between diabetic and control rats. In conclusion, despite the morphological changes found in chronic diabetic rats, the activity of the ADN, examined by two different approaches, was not altered in acute or chronic states.
Support: FAPESP, CAPES, CNPq.