Paraoxonase polymorphism in northwestern Indians.
OBJECTIVE
The aim of this study was to distinguish paraoxonase phenotypes by dual substrate method.


METHODS
166 unrelated healthy northwestern Indian Punjabis were studied for basal paraoxonase activity (P), in presence of 1 M NaCl (salt-activated) using paraoxon as substrate and arylesterase activity (A) using phenylacetate as substrate.


RESULTS
The mean (+ SD) activity of these in population was 70.43 (+/-30.41), 103.11 (+/-42.87) nmol/min/ml plasma and 36.81 (+/- 9.87) micromol/min/ml plasma, respectively, with no significant difference in sexes. Based on the ratio of SAP activity to A activity, 3 distinct phenotypes could be determined with gene frequencies of PON*A and PON*B being 0.845 and 0.155, respectively. Between P and A, and SAP and A in both A and AB phenotypes, significant correlation was observed (A = r 0.34 and 0.62, p < 0.01; B = r 0.31 and 0.81, p > 0.01), suggesting that both enzymes belong to the same group.


CONCLUSIONS
Though northwestern Indian Punjabis have trimodal paraoxonase activity, the majority is either low homozygous (AA) or heterozygous (AB) type with enzyme activity lower than Europids.
Singh
S
S
Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Verma
M
M
Nain
C K
CK
Co
L
L
Goel
R C
RC
Sharma
B K
BK
D000328:Adult; D000483:Alleles; D043303:Aryldialkylphosphatase; D004789:Enzyme Activation / Q000187:drug effects; D004950:Esterases / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011110:Polymorphism, Genetic; D012727:Sex Characteristics; D012965:Sodium Chloride / Q000494:pharmacology
D012965:Sodium Chloride; D004950:Esterases; D043303:Aryldialkylphosphatase