|
|
||||||||
a Departamento de Morfologia, Instituto de Biociências - UNESP, Botucatu, SP, Brazil
b United States Environmental Protection Agency, Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Research Triangle Park, North Carolina 27711
c Olson Biochemistry Laboratories, South Dakota State University, Brookings, South Dakota 57007
d Department of Biological Science, York College of Pennsylvania, York, Pennsylvania 17405
Guanethidine, a chemical that selectively blocks sympathetic noradrenergic neurons, was used to investigate the role of sympathetic innervation in the fertility of rat epididymal sperm, using both natural mating and in utero insemination protocols. This animal model correlates, at least in part, with spinal cord injury (SCI) in men. Adult male rats were treated daily by i.p. injections, for 21 or 42 days, with 0 or 6.25 mg/kg guanethidine. To compare the effects of guanethidine-induced sympathectomy with those following surgically induced sympathectomy, the inferior mesenteric ganglion and the proximal hypogastric nerves were removed in another group of rats. Both chemically and surgically induced sympathectomy increased the weight of the epididymis and seminal vesicles/coagulating glands as well as the number and the transit time of cauda epididymal sperm. Neither serum testosterone levels nor LH was affected by treatment with guanethidine. Using natural mating, no litters were produced by guanethidine-treated rats. Chemically denervated rats failed to produce copulatory plugs or ejaculate into the uterus. However, distal cauda epididymal sperm from chemically or surgically denervated rats displayed normal fertilization ability (80%) using in utero inseminations. In addition, the sperm of denervated rats did not show abnormal sperm chromatin structure using an assay that detects DNA damage. We conclude that sympathectomy delays the transit of sperm through the cauda epididymidis and produces ejaculatory dysfunction but does not compromise sperm quality in the distal cauda epididymidis. Moreover, these data provide compelling evidence that there is no association between the prolonged transit time of sperm within the epididymis, i.e., pre-ejaculatory sperm aging, and the fertility of those sperm, which has important implications for artificial insemination using sperm from men with SCI.
2 Correspondence: Wilma De Grava Kempinas, Departamento de Morfologia, Instituto de Biociências - UNESP, 18618 000 Botucatu, SP, Brazil. FAX: 55 14 821 3744; kempinas{at}surfnet.com.br
This article has been cited by other articles:
![]() |
A. M. Silva, D. B.C. Queiroz, E. F. Castro Neto, M. d. G. Naffah-Mazzacoratti, R. O. Godinho, C. S. Porto, G. Gutierrez-Ospina, and M. C. W. Avellar Segment-Specific Decrease of Both Catecholamine Concentration and Acetylcholinesterase Activity Are Accompanied by Nerve Refinement in the Rat Cauda Epididymis During Sexual Maturation J Androl, May 1, 2002; 23(3): 374 - 383. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. B.C. Queiroz, F. R. Mendes, C. S. Porto, and M. C. W. Avellar {alpha}1-Adrenoceptor Subtypes in Rat Epididymis and the Effects of Sexual Maturation Biol Reprod, February 1, 2002; 66(2): 508 - 515. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Marostica, E. F. Guaze, M. C. W. Avellar, and C. S. Porto Characterization of Muscarinic Acetylcholine Receptors in the Rat Epididymis Biol Reprod, October 1, 2001; 65(4): 1120 - 1126. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. D. G. Kempinas,, J. D. Suarez,, N. L. Roberts,, L. Strader,, J. Ferrell,, J. M. Goldman,, and G. R. Klinefelter Rat Epididymal Sperm Quantity, Quality, and Transit Time after Guanethidine-Induced Sympathectomy Biol Reprod, October 1, 1998; 59(4): 890 - 896. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |