Purine nucleoside phosphorylase and the enzymatic antioxidant defense system in breast milk from women with different levels of arsenic exposure.
Purine nucleoside phosphorylase (PNP) is an ubiquitous enzyme which plays an important role in arsenic (As) detoxification. As is a toxic metalloid present in air, soil and water; is abundant in the environment and is readily transferred along the trophic chain, being found even in human breast milk. Milk is the main nutrient source for the growth and development of neonates. Information on breast milk synthesis and its potential defense mechanism against As toxicity is scarce. In this study, PNP and antioxidant enzymes activities, as well as glutathione (GSH) and total arsenic (TAs) concentrations, were quantified in breast milk samples. PNP, superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) activities and GSH concentration were determined spectrophotometrically; TAs concentration ([TAs]) was measured by atomic absorption spectrometry. Data suggest an increase in PNP activity (median = 0.034 U mg protein-1) in the presence of TAs (median = 1.16 g L(-1)). To explain the possible association of PNP activity in breast milk with the activity of the antioxidant enzymes as well as with GSH and TAs concentrations, generalized linear models were built. In the adjusted model, GPx and GR activities showed a statistically significant (p<0.01) association with PNP activity. These results may suggest that PNP activity increases in the presence of TAs as part of the detoxification mechanism in breast milk.
Centro de Investigaciones Biológicas del Noroeste, S.C. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, Baja California Sur, C.P. 23096. Hospital General de Zona No.1. Instituto Mexicano del Seguro Social. 5 de febrero y Héroes de la Independencia, Centro, La Paz Baja California Sur, C.P. 23000.. r.gaxiolar@gmail.com.
Ramón
R
Gaxiola-Robles
Centro de Investigaciones Biológicas del Noroeste, S.C. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, Baja California Sur, C.P. 23096.. vlabrada@gmail.com.
Vanessa
V
Labrada-Martagón
Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano del Seguro Social (IMSS), Sierra Mojada 800, Colonia Independencia, CP: 44340, Guadalajara, Jalisco. México.. kurtbitzer@gmail.com.
Oscar Kurt
OK
Bitzer-Quintero
Centro de Investigaciones Biológicas del Noroeste, S.C. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, Baja California Sur, C.P. 23096.. tzenteno04@cibnor.mx.
Tania
T
Zenteno-Savín
Centro de Investigaciones Biológicas del Noroeste, S.C. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, Baja California Sur, C.P. 23096.. lmendez04@cibnor.mx.
Lía Celina
LC
Méndez-Rodríguez
D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D001151:Arsenic / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008658:Inactivation, Metabolic; D008800:Mexico; D008895:Milk, Human / Q000737:chemistry* / Q000201:enzymology; D011683:Purine-Nucleoside Phosphorylase / Q000032:analysis*
D000975:Antioxidants; D011683:Purine-Nucleoside Phosphorylase; D001151:Arsenic