Survival mechanisms in a physiological oxidative stress model.
The Syrian hamster Harderian gland has as the remarkable feature of an extraordinary rate of porphyrin production, even higher than the liver. The low activity of the last enzyme of the route gives rise to the accumulation of the uncomplex porphyrins in the female glands. Moreover, due to the localization of the Harderian gland, porphyrins exposed to light produce reactive oxygen species and, thus, the gland presents a physiological oxidative stress, with a great number of sings of degeneration, but without compromising the gland integrity. The appearance of abnormal features in this gland was largely described in the past, but the significance is interpreted for the first time in this study. We have found that autophagic processes are the first result of an elevated porphyrin metabolism, as it is observed in both sexes. This mechanism is considered, in this case, as a constant renovation system that allows the normal gland activity to be sustained. Furthermore, there is a second procedure, invasive processes toward connective tissue, which even occasionally reach blood vessels with intravasation of damaged gland components into the bloodstream. This effect is a consequence of a strong oxidative stress environment that is mainly observed in the female gland, resembling to tumoral progression. Both mechanisms, autophagy and invasive processes, have to be implied in the maintenance of the gland integrity.
Tomás-Zapico
Cristina
C
Departamento de Morfología y Biología Celular, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
Caballero
Beatriz
B
Sierra
Verónica
V
Vega-Naredo
Ignacio
I
Alvarez-García
Oscar
O
Tolivia
Delio
D
Rodríguez-Colunga
María Josefa
MJ
Coto-Montes
Ana
A
D000818:Animals; D017209:Apoptosis; D001343:Autophagy; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002401:Cathepsin B / Q000096:biosynthesis; D002402:Cathepsin D / Q000096:biosynthesis; D056655:Cathepsin H; D002403:Cathepsins / Q000096:biosynthesis / Q000378:metabolism; D006224:Cricetinae; D003546:Cysteine Endopeptidases / Q000096:biosynthesis; D018450:Disease Progression; D005260:Female; D006243:Harderian Gland / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D008954:Models, Biological; D015233:Models, Statistical; D018384:Oxidative Stress; D011166:Porphyrins / Q000378:metabolism; D017382:Reactive Oxygen Species; D012737:Sex Factors
D011166:Porphyrins; D017382:Reactive Oxygen Species; D002403:Cathepsins; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; D056655:Cathepsin H; D002402:Cathepsin D