Acute Experimental Diabetes and Aortic Depressor Nerve Ultrastructural Morphometry: Effects of Insulin TreatmentFabrício Singaretti de Oliveira1, Milena Menezes de Amorim2,3, Jaci Airton Castania4, Helio Cesar Salgado4, Randy Alan Nessler3, Valéria Paula Sassoli Fazan2,3,5*
- Corresponding Author:
- Valéria Paula Sassoli Fazan
Department of Surgery and Anatomy
School of Medicine of Ribeirão Preto
USP, Av. Bandeirantes 3900, Ribeirão Preto
SP, Brazil and Central Microscopy Research Facility
The University of Iowa, Iowa City, IA, USA
Tel: +55 16 3602-4634
Fax: +55 16 3633-0017
E-mail: [email protected], [email protected]
Received Date: September 03, 2014; Accepted Date: September 23, 2014; Published Date: September 25, 2014
Citation: Oliveira FS, Amorim MM, Castania JA, Salgado HC, Nessler RA, et al. (2014) Acute Experimental Diabetes and Aortic Depressor Nerve Ultrastructural Morphometry: Effects of Insulin Treatment. Anat Physiol 4:159. doi:10.4172/2161-0940.1000159
Copyright: © 2014 Oliveira FS et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Previous results from our laboratory showed myelinated fiber alterations in the aortic depressor nerve (ADN) from rats rendered diabetic for 15 days (short term). The ultrastructure and the acute effect of insulin treatment, particularly in the unmyelinated fibres of this nerve, were not yet investigated in this experimental model, being the aim of this work. Wistar rats received a single intravenous injection of streptozotocin (STZ – 40 mg/Kg) 15 days (N=7) before the experiments. Control animals (N=7) received vehicle (citrate buffer) and treated animals (n=6) received a subcutaneous injection of insulin (10 IU/Kg) on a daily basis beginning 3 days after the STZ injection. Under pentobarbital anaesthesia the ADNs were isolated and had their spontaneous activity recorded. Afterwards, proximal and distal segments of the nerves were prepared for transmission electron microscopy studies. Morphometry of the myelinated and unmyelinated fibres was carried out with the aid of computer software. Nerves from diabetic animals showed some unmyelinated fiber enlargement with signs of swelling and degeneration, and the Schwann cells mitochondria presented enlargement and clustering formation. On treated animals, an important thickening of the Schwann cells’ basement membrane was present and some myelinated fibers showed thin myelin sheaths. The endoneural blood vessels ultrastrucutre was preserved in all nerves from the three experimental groups. Myelinated axon area and diameter was significantly larger on insulin treated animals, compared to both, controls and acute diabetic groups, on both segments. No other differences were observed between groups for the myelinated or unmyelinated fibers morphometric parameters. Investigation of experimental models of diabetes in early or acute stage of the disease provide relevant information on the physiopathological mechanisms involved in the alterations present in patients with chronic diabetes and its complications. We suggest that insulin treatment alone might have a role on the morphological alterations present in diabetic neuropathy.