Preproinsulin I and II mRNA expression in adult rat submandibular glands.
Mammalian salivary glands are known to produce a number of biologically active peptides. The aim of this study was to extend our previous results showing the presence of a biologically active insulin-like immunoreactive peptide in rat salivary glands. In rodents, where two nonallelic and functional insulin genes are expressed, the co-expression of both genes seems to be limited to beta-cells of pancreatic islets or to embryologic developmental processes. We have investigated the expression of insulin genes in rat submandibular glands and in a murine immortalized submandibular cell line, SCA-9. For this purpose, total RNAs were isolated and submitted to reverse transcription. The cDNAs obtained were amplified by a nested polymerase chain reaction using rat preproinsulin I and II primers. Our data show that both preproinsulin I and II mRNAs are expressed in adult rat submandibular glands as well as in the SCA-9 cell line. The identification of salivary gland rat preproinsulin I and II was confirmed by direct sequencing. These results provide, for the first time, evidence for the expression of both preproinsulin I and II mRNA in an extra-pancreatic tissue from adult rodents.
Egéa
J C
JC
Laboratoire de Physiologie, Faculté d'Odontologie, Montpellier, France. jc.egea@wanadoo.fr
Hirtz
C
C
Gross
R
R
Lajoix
A D
AD
Traskawka
E
E
Ribes
G
G
de Périère
D D
DD
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015870:Gene Expression; D007328:Insulin; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011384:Proinsulin / Q000096:biosynthesis* / Q000235:genetics; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA; D013363:Submandibular Gland / Q000378:metabolism*
D007328:Insulin; D011498:Protein Precursors; D012333:RNA, Messenger; C013737:preproinsulin; D011384:Proinsulin