Sh. S. Tashaev
Received: 17 March 1980
Key Words adaptation - hemorrhage - hypotension - hypertension - reinfusion
Studies on the importance of sympathetic innervation, adrenergic receptors, and a possible local catecholamine production in the development of patellar tendinopathy (tendinosis) in man |
| Patrik Danielson 1 *, Håkan Alfredson 2, Sture Forsgren 1 |
| 1Department of Integrative Medical Biology, Section for Anatomy, Umeå University, Umeå, Sweden 2Department of Surgical and Perioperative Science, Sports Medicine, Umeå University, Umeå, Sweden |
| email: Patrik Danielson (patrik.danielson@anatomy.umu.se) |
*Correspondence to Patrik Danielson, Department of Integrative Medical Biology, Section for Anatomy, Umeå University, SE-901 87 Umeå, Sweden
Funded by:
Faculty of Medicine at Umeå University The Swedish National Centre for Research in Sports The County Council of Västerbotten The Arnerska Research Foundation
| Keywords |
tyrosine hydroxylase •  (alpha)-1 • (alpha)-2A •  (beta)-1 • adrenoreceptors • tenocytes |
| Abstract |
| Changes in the patterns of production and in the effects of signal substances may be involved in the development of tendinosis, a chronic condition of pain in human tendons. There is no previous information concerning the patterns of sympathetic innervation in the human patellar tendon. In this study, biopsies of normal and tendinosis patellar tendons were investigated with immunohistochemical methods, including the use of antibodies against tyrosine hydroxylase (TH) and neuropeptide Y, and against 1-, 2A-, and 1-adrenoreceptors. It was noticed that most of the sympathetic innervation was detected in the walls of the blood vessels entering the tendon through the paratendinous tissue, and that the tendon tissue proper of the normal and tendinosis tendons was very scarcely innervated. Immunoreactions for adrenergic receptors were noticed in nerve fascicles containing both sensory and sympathetic nerve fibers. High levels of these receptors were also detected in the blood vessel walls; 1-adrenoreceptor immunoreactions being clearly more pronounced in the tendinosis tendons than in the tendons of controls. Interestingly, immunoreactions for adrenergic receptors and TH were noted for the tendon cells (tenocytes), especially in tendinosis tendons. The findings give a morphological correlate for the occurrence of sympathetically mediated effects in the patellar tendon and autocrine/paracrine catecholamine mechanisms for the tenocytes, particularly, in tendinosis. The observation of adrenergic receptors on tenocytes is interesting, as stimulation of these receptors can lead to cell proliferation, degeneration, and apoptosis, events which are all known to occur in tendinosis. Furthermore, the results imply that a possible source of catecholamine production might be the tenocytes themselves. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. |
Molecular and Cellular Biology and Pathobiology Program, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
White adipose tissue (WAT) is innervated by the sympathetic nervous system (SNS), and the central origins of this innervation have been demonstrated for inguinal and epididymal WAT (iWAT and eWAT, respectively) using a viral transneuronal tract tracer, the pseudorabies virus (PRV). Although the more established role of this sympathetic innervation of WAT is as a major stimulator of lipid mobilization, this innervation also inhibits WAT fat cell number (FCN); thus, local denervation of WAT leads to marked increases in WAT mass and FCN. The purpose of this study was to extend our understanding of the SNS regulation of FCN using neuroanatomical and functional analyses. Therefore, we injected PRV into retroperitoneal WAT (rWAT) to compare the SNS outflow to this pad from what already is known for iWAT and eWAT. In addition, we tested the ability of local unilateral denervation of rWAT or iWAT to promote increases in WAT mass and FCN vs. their contralateral neurally intact counterparts. Although the overall pattern of innervation was more similar than different for rWAT vs. iWAT or eWAT, its SNS outflow appeared to involve more neurons in the suprachiasmatic and solitary tract nuclei. Denervation produced significant increases in WAT mass and FCN for both iWAT and rWAT, but FCN was increased significantly more in iWAT than in rWAT. These data suggest differences in origins of the sympathetic outflow to WAT and functional differences in the WAT SNS innervation that could contribute to the differential propensity for fat cell proliferation across WAT depots in vivo.