The regeneration of corneal nerve in the graft after penetrating partial homo-keratoplasty had been observed histologically in the experimental rabbits and also the influence of thiamine hydrochloride on nerve regeneration had been studied. Cornea-grafts obtained from the central portion of the cornea by 6 mm trephine were transplanted each other among the rabbits and given 8 sutures in situ under deep sodium pentobarbital anesthesia. Thiamine hydrochloride were given daily does of 5 mg/kg body weight to the grouped rabbits intramuscularly. Enuculeations were done in 5 days, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 18, 20, 22, 24, 26, and 27 weeks after transplantation. Preparations were made with 10-15 micro paraffiserial sections, both of cross and flat, and modified Romanes' silver stain was applied. The results were as follows: 1) Control group: In 5 days after operation, fine nerve fibes were regenerated from the cutted nerve stumps of the host-cornea. After I weeks, nerve plexus were formed in the host-cornea around scar tissue and few fibers penetrated into the scar tissue. After 2 weeks, fine regenerating nerve fibers were found in the transplanted cornea-grafts. Thereafter, numbers and size of the regenerated nerve fibers increased gradually. In 9 weeks after transplantation, nerve innervation in the transplanted cornea-graft was similar to normal cornea. 2) Thiamine hydrochloride treated group: In 5 days after operation, fine regenerating nerve sprouts from the cutted nerves tumps in the host-cornea formed loose nerve plexus and few fibers penetrated into the scar tissue. After 1 week, regenerating nerve fibers were already found in the periphery of the transplanted cornea-grafts. In process of experimental time, nerve fibers in the cornea-grafts more actively regenerated compared with control group. In 7 weeks after homo-corneal transplatation, nerve innervation in the grafts was the same as normal cornea. 3) Thiamine hydrochloride remarkably accelerated nerve regeneration in the transplanted cornea-grafts after penetrating partial homo-keratoplasty.
Anesthesia ; Body Weight ; Cicatrix ; Cornea ; Nerve Fibers ; Nerve Regeneration* ; Pentobarbital ; Rabbits* ; Regeneration ; Silver ; Sodium ; Sutures ; Thiamine ; Transplants

PURPOSE: The sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA), encoded by ATP2A2, is an essential component for G-protein coupled receptor (GPCR)-dependent Ca(2+) signaling. However, whether the changes in Ca(2+) signaling and Ca(2+) signaling proteins in parotid acinar cells are affected by a partial loss of SERCA2 are not known. MATERIALS AND METHODS: In SERCA2(+/-) mouse parotid gland acinar cells, Ca(2+) signaling, expression levels of Ca(2+) signaling proteins, and amylase secretion were investigated. RESULTS: SERCA2(+/-) mice showed decreased SERCA2 expression and an upregulation of the plasma membrane Ca(2+) ATPase. A partial loss of SERCA2 changed the expression level of 1, 4, 5-tris-inositolphosphate receptors (IP(3)Rs), but the localization and activities of IP3Rs were not altered. In SERCA2(+/-) mice, muscarinic stimulation resulted in greater amylase release, and the expression of synaptotagmin was increased compared to wild type mice. CONCLUSION: These results suggest that a partial loss of SERCA2 affects the expression and activity of Ca(2+) signaling proteins in the parotid gland acini, however, overall Ca(2+) signaling is unchanged.
Amylases/metabolism ; Animals ; Blotting, Western ; Calcium/metabolism ; Calcium Signaling/drug effects/genetics/*physiology ; Carbachol/pharmacology ; Immunohistochemistry ; Inositol 1,4,5-Trisphosphate Receptors/metabolism ; Mice ; Mice, Knockout ; Parotid Gland/*metabolism ; Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics/*metabolism ; Signal Transduction/drug effects/genetics/physiology

Synaptotagmin is a Ca2+ sensing protein, which triggers a fusion of synaptic vesicles in neuronal transmission. Little is known regarding the expression of Ca2+ - dependent synaptotagmin isoforms and their contribution to the release of secretory vesicles in mouse and rat parotid acinar cells. We investigated a type of Ca2+ - dependent synaptotagmin and Ca2+ signaling in both rat and mouse parotid acinar cells using RT-PCR, microfluorometry, and amylase assay. Mouse parotid acinar cells exhibited much more sensitive amylase release in response to muscarinic stimulation than did rat parotid acinar cells. However, transient [Ca2+]i increases and Ca2+ influx in response to muscarinic stimulation in both cells were identical, suggesting that the expression or activity of the Ca2+ sensing proteins is different. Seven Ca2+ - dependent synaptotagmins, from 1 to 7, were expressed in the mouse parotid acinar cells. However, in the rat parotid acinar cells, only synaptotagmins 1, 3, 4 and 7 were expressed. These results indicate that the expression of Ca2+ - dependent synaptotagmins may contribute to the release of secretory vesicles in parotid acinar cells.
Synaptotagmins/*metabolism ; Signal Transduction ; Rats ; Protein Isoforms/metabolism ; Parotid Gland/cytology/*metabolism ; Muscarinic Agonists/pharmacology ; Mice ; Exocytosis/drug effects/physiology ; Carbachol/pharmacology ; Calcium/metabolism/*physiology ; Animals ; Amylases/secretion