Localization of vesicular inhibitory amino acid transporter (VIAAT) in the submandibular salivary gland throughout the postnatal development of mice / Localización del transportador vesicular de aminoácidos inhibidores (VIAAT) en la glándula salival submandibular durante el desarrollo postnatal de ratones

According to recent studies, it is highly possible that the occurrence of vesicular inhibitory amino acid transporter (VIAAT) is a good marker of GABA-signaling not only in the brain, but also in extra-brain tissue cells containing GABA and GAD. In view of this, the present study was attempted to localize VIAAT-immunoreactivity in the submandibular gland of mice. In the present study, the submandibular glands of male mice at various postnatal developmental stages were examined for detailed localization of VIAAT-immunoreactivity in immunohistochemistry at light microscopic level. The immunoreactivity for VIAAT was localized in epithelial cells of proximal and distal excretory ducts with the striated portion more intensely immunopositive at young postnatal stages. No significant immunoreactivity was seen in the acinar cells throughout the postnatal development. In addition, the immunoreactivity for VIAAT was detected in the salivary parasympathetic ganglionic neurons, but not in any nerve fibers surrounding the glandular cells. Furthermore, VIAAT-immunoreactivity was found in smooth muscle cells forming the outermost layer of intralobular arterioles. From the present findings, it is possible that GABA plays roles as paracrine and autocrine regulators in the saliva secretion as well as the gland development.

Según estudios recientes, es altamente posible que la aparición del transportador vesicular de aminoácidos inhibidores (VIAAT) sea un buen marcador de señalización de GABA no sólo en el cerebro, sino también en células de tejido extra-cerebrales que contienen GABA y GAD. En el presente estudio se intentó localizar inmunoreactividad a VIAAT en la glándula submandibular de ratones. En el presente estudio, se examinaron las glándulas submandibulares de ratones machos en las distintas etapas del desarrollo postnatal para la localización detallada de inmunoreactividad a VIAAT inmunohistoquímicamente a nivel de microscopía óptica. La inmunorreactividad para VIAAT se localizó en las células epiteliales de los conductos excretores proximal y distal, con mayor intensidad en la porción estriada en las etapas tempranas. No se observó inmunoreactividad significativa en las células acinares durante el desarrollo postnatal. Además, se detectó la inmunoreactividad para VIAAT en las neuronas ganglionares parasimpáticas salivales, pero no en las fibras nerviosas que rodean las células glandulares. Además, la inmunoreactividad a VIAAT se encuentra en las células del músculo liso que forman la capa más externa de las arterias interlobulillares. En base a estos hallazgos, es posible que GABA tenga una función como regulador autocrino y paraparacrino en la secreción de saliva, así como en el desarrollo de la glándula.

Primary culture and identification of mouse PASMCs and effects of hy-poxia on proliferation and apoptosis of PASMCs / 中国病理生理杂志

AIM:To establish a fast , accurate and economical technique for culturing mouse pulmonary arte-riolar smooth muscle cells ( PASMCs ) , and to explore the effects of hypoxia on the proliferation and apoptosis of the PASMCs.METHODS:In sterile condition, the pulmonary artery was isolated from the male BALB/c mice by digesting with collagenase I, and the cells were cultured in fetal bovine serum-coated flask.Centrifugal procedure was not used dur-ing the cell passage .The cell morphology was observed under an inverted phase-contrast microscope .α-Smooth muscle ac-tin was identified by immunocytochemistry and immunofluorescence .The effects of hypoxia on the proliferation and apopto-sis of the PASMCs were detected by CCK-8 assay and TUNEL assay .RESULTS:PASMCs were identified by the methods of immunocytochemistry , immunofluorescence staining and observation of morphology .Unlike the rat PASMCs with typical subcultured peak-vally pattern, the mouse PASMCs showed a lot different without a peak-vally pattern.The cells could be subcultured after 5 d to 7 d and there was 3 to 5 generations depending on the activity of the cells .CCK-8 assay demonstra-ted that the A values of PASMCs exposed to hypoxia increased after 24 h ( P<0.05) as compared with normoxia .TUNEL result showed that the apoptotic index of the PASMCs in hypoxia decreased after 24 h (P<0.05).CONCLUSION:This technique for obtaining cultured mouse PASMCs is simple , fast, accurate and economical .The digestion time is easy to control.Hypoxia promotes the proliferation and inhibits the apoptosis of PASMCs .