Regrowth of lymphatic vessels following transection of the muscle coat in the rat small intestine

Abstract

Regeneration of lymphatic vessels after transection of the muscle coat in the rat jejunum was studied by histochemical methods. The lymphatic regrowth occurred behind the regeneration of blood vessels. Enzyme histochemistry for 5'-nucleotidase (5'-Nase) demonstrated the manner of lymphatic regrowth, which was essentially attributed to vascular sprouting from preexisting lymphatics, and structural changes of the endothelial cells indicating their high migratory potential. The lymphatic regeneration progressively advanced with vascular maturation throughout the experimental period. The expression of 5'-Nase in the regenerating lymphatics was increased in proportion to their growth. VEGF-C, a highly specific lymphangiogenic factor, was highly expressed in a subpopulation of interstitial cells, being close to the regrowing lymphatics with immunoreactivity of its receptor, VEGFR-3, in the regenerative area. The present findings suggest that transection of the intestinal muscle coat affords a useful experimental model for the investigation of lymphatic regeneration in tissue repair and that the interstitium may play a crucial role in lymphangiogenesis.

Topographic study on nerve-associated lymphatic vessels in the murine craniofacial region by immunohistochemistry and electron microscopy

“…1e). onstrated lymphatic vessels with significant immunoreactivity in all preparations as reported in our previous studies (21)(22)(23). SEM examination of the LYVE-1-immunostained tissues further allowed a precise analysis of distribution and structure of the lymphatics.…”

“…The deparaffinized sections were incubated in a 0.01 M citrate buffer (pH 6.0) at 121°C for 15 min to retrieve antigenicity of the objective proteins before immunostaining. Immunostaining was performed as previously described (21,23). Some tissue sections for light microscopy were immersed in 0.3% H 2 O 2 in 1/15 M phosphate buffered saline (PBS; pH 7.4) containing 0.1% sodium azide (Wako Pure Chemical Industries, Osaka) at room temperature for 20 min to block the endogenous peroxidase activity.…”

Abnormal recruitment of periendothelial cells to lymphatic capillaries in digestive organs of angiopoietin-2-deficient mice

“…Immunostaining was performed as previously described (Shimoda et al 2003(Shimoda et al , 2004. In brief, the specimens were incubated in rabbit antibody against LYVE-1 (AngioBio, Calif., USA), followed by the use of the streptavidin-biotin method (Histofine, Nichirei, Tokyo, Japan).…”

“…Several tissue specimens fixed with Karnovsky's fixative were processed for scanning electron microscopy (SEM) as described previously (Shimoda et al 2001(Shimoda et al , 2004. Briefly, they were macerated with 6 N NaOH at 60°C for 10-15 min, stained with 1% osmium tetroxide solution, dehydrated in a graded ethanol series, freeze-dried by t-butylalcohol, and observed under an S-800 scanning electron microscope (Hitachi, Tokyo, Japan).…”

“…Although many of the mice lacking Ang2 die within 2 weeks of birth (Gale et al 2002), we have obtained multiple surviving adult mutant animals with severe lymphatic dysfunction (Hunter et al 2006) in order to examine the fine structure of their lymphatic capillaries. Hence, we have explored the precise structure of the lymphatic capillaries in Ang2 knockout and Ang1 knockin mice by focusing on the lymphatics in the digestive organs, which contain a welldeveloped lymphatic vasculature (Shimoda 1998;Shimoda and Kato 2006;Shimoda et al 1997Shimoda et al , 2001Shimoda et al , 2003Shimoda et al , 2004.…”