Tese
Função endócrina do interferon-tau durante o reconhecimento materno da gestação em ovinos
Fecha
2010-06-09Registro en:
ANTONIAZZI, Alfredo Quites. Endocrine action of interferon-tau during the maternal recognition of preganancy in sheep. 2010. 49 f. Tese (Doutorado em Medicina Veterinária) - Universidade Federal de Santa Maria, Santa Maria, 2010.
Autor
Antoniazzi, Alfredo Quites
Institución
Resumen
The objective of the present study is to evaluate interferon-tau (IFNT) endocrine
action in extra uterine tissues. The first approach consists of collecting samples from ewes on
days 12, 13, 14 and 15 of the estrous cycle or early pregnancy. The second, consists of
installing osmotic pumps to deliver a continuous concentration of recombinant ovine (ro)
IFNT into the uterine vein for 24 or 72 hours. Our hypothesis is that endocrine release of
IFNT into the uterine vein occurs as early as Day 13 of pregnancy. Also, that 24 and 72 hours
infusion of roIFNT induces ISGs in the CL, liver and endometrium and IFNT has endocrine
action on the CL to modulate major genes involved in luteolysis. Endometrium, liver, corpus
luteum, uterine vein, jugular and uterine vein blood were collected from cyclic (NP) and
pregnant (P) ewes on Days 12, 13, 14 and 15. Instalation of 24 and 72 hour pumps was done
on Day 10 of the estrous cycle. Half were infused with BSA and the other half with roIFNT.
Only in the 24 hour infusion, half of each group was challanged with a PGF injection at 12
hours following pump installation. Concentrations of progesterone in serum were similar on
Days 12 and 13 and then declined (P<0.05) to less than 1 ng/ml in NP ewes between Days 14
and 15. Endometrial ISG15 mRNA increased (P<0.05) in P versus NP ewes by Day 13 and
remained greater through Day 15. Endometrial ESR1 and OXTR mRNAs were up-regulated
(P<0.05) in NP compared to P ewes by Day 14, and remained up-regulated on Day 15.
Uterine vein ISG15 mRNA was not affected by pregnancy status. IFNAR1 and IFNAR2
mRNA were present in the CL, but did not change due to pregnancy status. ISG15 mRNA in
CL and liver increased (P<0.05) by Day 14 and remained up-regulated on Day 15 in P
compared to NP ewes. The expression of ESR1, OXTR, PTGFR, PTGER2, PTGER3 and
PTGER4 did not change in the corpus luteum during Days 12, 13, 14 and 15 related to
pregnancy status. Following the 24 hour infusion, ESR1, OXTR, PTGER2 and PTGER3
mRNA were not affected, but SLCO2A1 mRNA decreased (P<0.001) in BSA+PGF, roIFNT
and roIFNT+PGF compared to BSA-infused ewes. PTGFR mRNA was down regulated
(P<0.001) in roIFNT and roIFNT+PGF compared to BSA and BSA+PGF-infused ewes.
PTGER4 mRNA was greater (P<0.05) in roIFNT and roIFNT+PGF compared to BSA, but
not compared to BSA+PGF-infused ewes. After 72 hours, concentrations of progesterone did
not differ in roIFNT- compared to BSA-infused ewes. ISG15 mRNA was induced in the CL,
liver and endometrium in roIFNT- compared with BSA-infused ewes. Endocrine action of
IFNT occurred through up-regulation of ISG15 mRNA in CL and liver by Day 14 of
pregnancy. It is concluded that IFNT has endocrine effects on the CL between Days 13 and 14
of pregnancy and may protect the CL through mechanisms that are complementary, yet
independent to its paracrine effects on the OXTR endometrial pathway.